Student Text - MechanicalRailway diesel shed training notes

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General Motors Electro-Motive Model 567,645,and 710 Series Diesel Engine

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Acknowledgements

This course was prepared by International Technical Services, a division of 984326 Ontario Inc., in cooperation with the General .\lotors Locomotive Group Customer Training Center, Technical Publications Dept. and Engineering Departments.

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The course content is based partialy on previous publications produced by the Training Center, and pardy on information gathered by the Training Center from Electro-Motive's Service and Engineering Departments. The contents of Chapter 7 were extracted from the EMD document, The Electro-Motive Turbocharger by William Badurski.

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Developed in Cooperation with the General Motors Locomotive Group ElectdMotive Customer Training Center.

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Copyright, April, 1997 The content ofthis document is the property o f International Technical Services, a division of984326 Ontario Inc.. All rights reserved. Neither this document, nor any part thereof,may be regroduced or stored by any means without the expressed written consent of984326 Ontario Inc. Contact International Technical Services, 572 Wellington Street, London Ontario Canada, N6A 3R3 Tel(519) 439-2362, Fax 675-1868 Internet:[email protected].

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Second Edition Revision 1 August 1997

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/ABLE OF bONTENTS

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Chapter 7

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EMD Technical Publications & History EMD History ...................................................................... 1 .1 Engine Development ...................................................... 1 .4 Locomotive Development .............................................. 1 ,5 EMD Technical Publications ........................................... 1 .9 Locomotive Service Manual (LSM) ................................ 1.9 Engine Maintenance Manual..................................... 1 .1 1 Maintenance Instructions ........................................... 1.1 3 Service Pointers ............................................................ 1 14

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Chapter 2

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Introduction ..................................................................... 2.1 Engine Operating Cycles ............................................... 2.1 Four Stroke Engine .......................................................... 2.2 Two Stroke Engine ........................................................... 2.5 General Engine Arrangement .................................... 2.10 Internal Pressure Division ............................................. 2.13 Serial Numbers ............................................................. 2.14

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Diesel Engine Theory

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Chapter 3

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Engine Components and Construction Physical Layout .......................................................................... 567-645-710 Engine Evolution .................................................... Cross Sectional Engine Diagram .............................................. Components .............................................................................. Crankcase .................................................................................. Crankcase Comparison ............................................................ Main Bearings and Crankshaft ............................................... Crankshaft ................................................................................ Torsional Dampers ................................................................... Types of Oil Pans ...................................................................... Power Packs (Assemblies) ....................................................... Cylinder Liner ........................................................................... Piston and Rings ....................................................................... Piston Carrier ............................................................................ Connecting Rods ..................................................................... Cylinder Head .......................................................................... Rocker Arm Assembly .............................................................. Hold Down Crab System ......................................................... Head Seat Ring ........................................................................ Camshafts ................................................................................ Clutch/Spring Drive Gear ........................................................ Accessory Drive ........................................................................ Engine Model Comparison 645 - 71 0 .....................................

3.1 3.4 3.4 3.5 3.5 3.8 3.lo 3.11 3-12 3.15 3.16 3.16 3.18 3.19 3.21 3-22 3.23 3.24 3.27 3.27 3.32 3.33 3.34

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Introduction ................................................................................ supply ......................................................................................... Delivery ....................................................................................... Unit Injector System ................................................................... Injector Operation ..................................................................... Injection Control ........................................................................ EMDEC Injection Control ........................................................... EMDEC Fuel Flow and System Components ............................ Electronic Fuel Control ............................................................ Fuel System Troubleshooting .................................................. EMDEC System Maintenance ................................................. Fuel System Troubleshooting EMDEC .....................................

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4.6 4.8 4.8 4.9 4.12 4.16 4.19 4.20

ElectrrjMotive Model 567. 645 8t 71 0 Series Diesel Engines

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Chapter 5

Introduction................................................................................. 5.1 Blower Type Cooling System ...................................................... 5.4 System Pressurization .................................................................. 5.4 Operating Water Level ............................................................... 5.5 Coolant ....................................................................................... 5.5 Water Pumps ............................................................................... 5.6 Low Water Shutdown .................................................................. 5.7 Radiators ..................................................................................... 5.8 System Maintenance ............................................................... 5.10 Cooling System Troubleshooting ............................................. 5.12

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Cooling System

Chapter 6

Lube Oil System Introduction................................................................................. Main Lubricating System ............................................................ Piston Cooling Oil System ........................................................... Scavenenging Oil System .......................................................... Oil Gauge .................................................................................... Piston Cooling Oil Pressure ......................................................... Scavenging Oil Strainer .............................................................. Scavenging Oil Pump ................................................................. Lube Oil Filter ............................................................................... Lube Oil Cooler ........................................................................... Lube Oil Strainer Housing ........................................................... Main & Piston Cooling Strainers (Fine) ...................................... Main Lube and Piston Cooling Pump ........................................ Lube Oil Pressure Relief Valve .................................................... Turbocharger Oil Filter ............................................................. Soakback System ...................................................................... Lube Oil Separator (Turbo and Blower) .................................. System Maintenance ............................................................... Lube Oil System Troubleshooting............................................ Prelubrication of Engines ..........................................................

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6.1 6.2 6.3 6.4 6.4 6.4 6.5 6.5 6.6 6.7 6.7 6.8 6.8

6.9 -6.10 6.10 6.11 6.12 ,6.14 6.22

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Chapter 7

Introduction................................................................................. Turbochargers .............................................................................

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Air Intake and Exhaust Systems

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Chapter 7 cont’d

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Component Familiarization....................................................... Doweling Assembly. ................................................................... Main Housing “Cradle” Gasket Area ........................................ Turbine Wheel .......................................................................... Turbocharger Bearings ............................................................ Turbocharger Labyrinth Seals ................................................. Turbine Inlet Scroll ............. .,...................................................... Nozzle Ring ............................................................................... Turbine Shroud & Retaining Clamp ........................................ Exhaust Diffuser ...................................................................... Exhaust Duct ............................................................................ Compressor Diffuser ................................................................ Planet Gears ............................................................................ Ring Gear & Clutch Housing ................................................... Clutch Camplate & Rollers ...................................................... Gear Drive System .................................................................. Lube Oil System ........................................................................ Soak Back System .................................................................... Planetary System Oil Drainage Screen ................................... Gear Train Operation .............................................................. Turbochargers with External Clutch ....................................... External Inspection & Diagnosis............................................ Roller Clutch Test ..................................................................... Turbocharger Oil Pressure Test ............................................... Run-Down Time Test ................................................................. Additional External Inspections .............................................. Additional Troubleshooting Information ................................ Overheat/Overspeed Failure .................................................. Foreign Material Damage to Turbine ..................................... Damage to Compressor Impeller ......................................... Clutch Failure ........................................................................... Lack of Proper Lubrication ...................................................... Bearing Failures........................................................................ Planetary Gear Train Failure .................................................... Turbine Blade Fatigue ........................................................... Failure Classification ................................................................ Overheat/Overspeed .............................................................. Foreign Material Damage to Turbine Sections ...................... Thrust Bearing Failure .............................................................. Compressor Bearing Failure .................................................... Turbine Bearing Failure ............................................................ Rotler Clutch Failure .................................................................

7.2 7.4 7.6 7.7 7.10 7.11 7.14 7.14 7.15 7.16 7.16 7.18 7.19 7.20 7.21 7.22 7-23 7.24 7.25 7.26 7-28 7-30 7.30 7.31 7.32 7-33 7.37 7.39 7.40 7.41 7.41 7.42 7.42 7.44 7.45 7.45 7.45 7.46 7.46 7.47 7.47 7.47

Electro-MotiveModel 567. 645 & 710 Series Diesel Engines

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Chapter 7 cont'd

Foreign Material Damage to Compressor Section ......,...,... 7.47 Planetary Gear Train Failure ....,..... .... . ................................... ,. 7.47 Lack of Proper Lubrication ......,..,......... .......,... 7.48 Turbine Blade fatigue Fracture .......... ............................. 7.48 Exhaust Gas Leak ........................ ...... .. ......... ....................... ,.. 7,48 Turbine Shroud Retaining Clamp Failure .,..... .... .... ................ 7.48 Poor Planetary Train Mesh .. . ................................... ,. 7.49 Internal Oil Leak ..................................................................... (. 7,49 External Gear Damage .,......,....... .... .. ., .......,... ......,,........,...., 7,49 Turbocharger InstallationTips .,,., . ..... ,.. ..,........,,.,........,......, ,, 7.49 Roots Blower ...., ...........,.,..,.............. ......... ,...... .......... ......... ... 7.51 Blower Inspection.....,.,, ,,,....., , . , ,,, . .. ....... ,. ........... ..,*...., ....... ., , , .. 7 -52 Exhaust System Components ................,,........................ ....., 7 -52 a

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Chapter 8

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Engine Speed Control Introduction..,.................. ........................................................ 8,l Speed Sensing and Fuel Control ......, ,.. .., ..........................,...... 8.2 Speed Control .........,.,., .....,.. ....II.....II.......I..I I. ........,.,........,.. 8.4 Load Regulation ........................... 8.6 Protective Devices..,.........,.....,.......,......,... ,...........,,................... 8.7 Governor Maintenance ,.........,,.. . ,,........,.....,., ,...........,....,........ 8,9 Governor Qualification ............................................................ 8.1 1 I . . I .

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Protective Devices Introduction.......,,........,............ ..... ........................,.. 9.1 EPD - Engine Protection Device ..,,. 9.1 Testing EPD Operation ........IIII.......I....IIIIIIII...I....I..IIII..III ..,,....... 9,2 Crankcase Pressure Detector (EMDEC) ...IIII....................II....I. 9.5 Hot Oil Detector...........,...I...I .... ....... ,.,........I . ..,. 9.7 Low Oil Shut Down ,,.,. ,,.,,.....,,, ,..,,,.......,.........,, ,.......,............,.,., 9.8 Engine Overspeed ..... ., .,..,.............,.,.. .....................,......,.. 9.9 .........I..,Iq

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ITS Locomotive Training Series Student Text

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CHAPTER EMD Technical Publications and History

History The General Motors Locomotive Group as we know it today was founded in 1922 with the creation of the Electro-Motive Engineering Company (EMC) in Cleveland, Ohio. EMC produced gasoline-electric railcars suited to light freight and passenger service as an alternative to steam powered engines. These 35 ton rail cars proved to be quite successful, and as a result approximately 500 were built between 1926 and 1932. EleCtreMotive wasfounded in Cleve/cmd Ohio in 7922.

The demand for more power resulted in the use of “Winton” gasoline engines ranging from 175 to 400 horsepower. A limited number of units were built using two of the 400 horsepower engines. Two major problems confronted the designers at EMC, those of space constraints due to the large engine size and the high cost of gasoline in comparison to alternative fuels. EMC attempted to develop their own distillate engine but were unsuccessful. In 1930, both the Electro-Motive Engineering Company and the Winton Engine Company were acquired by General Motors. With the assistance of General Motors Research, Winton soon produced their first diesel, the “Type 201” engine.

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Figure 1.1 The Winton Type 201 Engine

The eight cylinder 201 engine was built with 8" bores and a 10" stroke which developed 75 to 80 horsepower per cylinder at 750 revolutions per minute (rprn). The 201 pioneered many innovative concepts that have been passed on to the engines of today. Among them, the Winton 201 was designed with;

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lightweight design welded steel frame individual removable power assemblies, and unit injectors.

In 1933 a 600 horsepower version of the 201 was used to power the Burlington Railroads Pioneer Zephyr to a new speed record between Chicago and Denver. T h e Zephyr completed the trip in thirteen hours and five minutes averaging 77.6 mph ( I 2 5 krnlh). Following this achievement there was considerable interest expressed by the railways in the development of true diesel locomotives.

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Figure 1.2 The 1933 Burlington Zephyr ElectreMotive Model 567, 645 & 710 Series Diesel Engines

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3 3 Interest was such that in 1935 General Motors undertook the construction of North America’s first Diesel-Electric locomotive plant at LaGrange Illinois. Design work on the diesel engine continued and a new series of engine, the 567 was ready for installation in 1936. A 567 engine was installed in the first locomotive produced at the LaGrange plant. This 600 horsepower switcher locomotive ran in regular service for the Santa-Fe-Railroad until 1975.

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The “567” indicated the number of cubic inches per cylinder and this engine was designed primarily for rail use. The 45” “V” design allowed for installation in narrow car-bodies and the two cycle engine provided a simplicity and ease of maintenance which was recognized as an advantage by the railways. Another significant advantage of the 567 design was the ability to manufacture the engine in 6,8,12 and 16 cylinder models to suit different horsepower demands.

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Figure 1.3 Typical General Motors ”Switcher”Locomotive

By 1938, E M C had assumed responsibility for the manufacture of all locomotive components, and in 1940 oficially became the Electro-Motive Division of General Motors.

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In 1949 General Motors of Canada, Diesel Division, established a plant in London, Ontario Canada to assemble locomotives for the Canadian Market. The General Motors Locomotive Group was formed in 1988 in order to pool the resources of the London and LaGrange plants.

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Engine Development The design of the diesel engine has continued to evolve over the years since the Winton and has seen the incorporation of many improvements. Many of the changes were in response to the customers ever increasing horsepower demands. By 1959 the horsepower of the basic 16 cylinder 567 engine had been increased to 1800 Hp.

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Figure 1.4 The 567 Series "Roots Blown" Engine

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Continuing research led to the introduction of the first turbocharged engine in 1959. The 16 cylinder 567D2 engine produced 2000 Hp. The 567 engine design reached its limit in 1964 with the introduction of the 2500 Hp 567D3A.

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Building on the success of the 567 engine, GM designers produced the first 645 series engine in 1966 by increasing the bore of the 567. Design work continued on the 645 model, still driven by higher horsepower requirements, but also by customer demands for improved fuel economy. The latest version of the 645 engine was the fuel efficient, 3600 Hp, 16 cylinder 645F3B engine.

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Figure 1.5 The Turbocharged 645 Engine 1-4

ElectreMotiveModel 567, 645 & 710 Series Diesel Engines

General Motors introduced the new 710G3 engine in 1984 rated at 3800 horsepower. While this engine is similar to the 645 configuration, the longer stroke of the 710 engine required some redesign to the engine block. This was the first major change to this reliable engine design since 1954. The 710 engine looks almost identical to the 645 model, except that the block is deeper between the air box and the top inspection covers to accommodate the longer stroke of the 710 power gssemblies. The durable and efficient design of these engines has been proven over the years not only in locomotive applications but also in marine applications, drilling rigs and stationary power plants. The newest addition to the General Motors locomotive line is the SD80MAC and SD90MAC locomotives. The SD80MAC Series unit is powered by a 20-710 turbocharged engine which is rated at 5000 tractive horsepower. T h e SD90MAC units were released with a 16-710 engine at 4300 tractive Hp, and are being retrofit with the new EMD designed "H" engine which will produce 6000 tractive Hp. These locomotives and the "H" engine are covered in separate training packages.

Locomotive Development Since the production of the first GM diesel electric switcher locomotive in 1936, locomotive design has kept pace with engine design to effectively deliver the ever increasing horsepower to the rails. Another challenge has been to continually improve the locomotives electrical and mechanical systems so as to provide the customer with the most efficient and reliable locomotive possible. While locomotive design has been a constantly evolving process, there have been several significant milestones, particularly in the technological advances made in the electrical system. The earliest models of GM locomotives were the; $ iW-1, SW-900 and SW-1200

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F-T, F-3, F-7 and F-9

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GP-7, GP-9 and GP-18 and

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SD-9, SD-7 and SD-18

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Figure 1.6 Typical F-PLocomotive

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The next generation of locomotives developed higher horsepower ratings and offered greatly improved electrical systems. One important electrical advance was the replacement of the direct current main generator with an alternating current main alternator. The main alternator offered improved ease of maintenance and increased control over the electrical system. This generation of locomotives included models such as,

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GP-38AC and GP-40 SD-38AC. SDP-40, SD-45 and SD-40

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Later models, known as Dash 2 locomotives offered further refinement to the electrical system. Most of the electrical modules which were mounted throughout the electrical cabinets were incorporated into cards mounted in a cabinet designed for ease of troubleshooting and change-out.

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Figure 1.7 Dash-2 Type Electronic Cards

All locomotive systems and component parts have undergone improvements over the years such as upgraded traction motors, air supply and filtration systems, car-body design, engine protection systems and a vast number of changes all designed to service the customers needs more effectively and economically.

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The design of the SD or GP-60 series locomotives added further technological advances to the GM locomotive which enhanced fuel economy, improved traction and wheel slip control, provided for self diagnostics and proved to be an extremely reliable IgGQgmtive.

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

Voltage Regulation And ’ Power Supply Display Equipment Excitation Computer Computer

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Figure 1.8 The 60 Series Microprocessor

The 60 Series locomotive replaced the Dash-2 type electronic cards nith microprocessor control technology. This eliminated the need for most of the relays in the electrical cabinet and allowed for a far superior control of the excitation and control systems. The microprocessor control allowed for engine crews and maintenance staff to perform much analysis of the 60 Series locomotive from the cab. Also added were many system diagnostic checks that could be run from the display key-pad. The 60 Series locomotive continued successfully to progress the technology demanded by the customer providing again improved fuel economy in an efficient 3800 horsepower locomotive. The 70 Series surpasses the 60 Series in terms of fuel economy, improved tractive effort and control systems in a 4000 horsepower locomotive. Some of the changes to the 70 Series unit are, the faster EM2000 computer system, 4000 tractive horsepower delivered by the 710G3B engine, improved fuel economy, the “steering” HTCR radial truck, higher capacity D-90 traction motors and several technologically .advanced options such as ICE

(integrated cab electronics) and the Micro electronic braking system. Figure 1.9 The 70 Series Locomotive

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3 The EM2000 computer system has also been incorporated into the n e w SD80MAC and SD90MAC locomotives. These units offer AC traction motors and improvements in truck performance with the HTCR-11. Additionally, these units are equipped with EMDEC electronic fuel injection, and further perfornance enhancements.

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Figure 1.10 The EM2000 Computer Chassis

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The SD80MAC is equipped with a 20-710 engine which produces 5000 Tractive Hp. The SD90MAC units were put into service with a 16-710 engine at 4300 Tractive Hp and are being retrofit with the new EMD "H" Model engine. An "H" engine

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equipped SD90MAC will produce 6000 Tractive Hp.

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Figure 1.11 SD8OMAC / SD9OMAC Carbody Design

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Electro-MotiveModel 567, 645 & 710 Series Diesel Engines

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Electro-MotiveTechnical Publications

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General Motors diesel electric locomotives are complex units made up of many components and sub-systems. To assiit in the proper maintenance of this equipment, technical publications have been produced. These publications contain valuable procedures and service data.

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In this section of the chapter we will examine four of the technical publications produced by the GM Electro-Motive Division.

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Technical Publications are provided to assist in the maintenance and repair of

Locomotive Service Manual Engine Maintenance Manual Maintenance Instructions Service Pointers

EM0 1ocomotives.

This section will demonstrate the types of information contained in each of these publications, how to find specific information, and provide an opportunity to practice with this material. As you are working through the chapter, it is suggested that you have copies of the

various publications available to refer to. All of these publications are very useful on the job.

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Locomotive Service Manual (LSM) Electro-Motive Division produces Locomotive Service Manuals in "generic" formats and, more commonly, for customer specific locomotive orders. The manual contains most of the service information for the locomotive, with the exception of the diesel engine, which is covered in its own manual. When referring to the index at the front of the Locomotive Service Manual you will notice it is divided into sections, each section dealing with a specific subject. Each section title serves as a description of the type of information contained in that section. For example, you find information dealing with the Compressed Air System in Section 6. The most important point to remember when using these manuals is to know specifically what information you are looking for. If you know what system you are working on, then it is easy to look in the index for this system, and quickly find the service information.

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Section "0"- General Information The sections of the LSM can be identified by the page numbers at the bottom. T h e first number identifies the section, the second number is the page number within that section. For example in Section 0 entitled General Information, the pages are numbered 0-1 through 0-9. This section is unique, in that, it does not cover any system in detail, but provides:

The EMD Locomotive Service Manual provides technical and maintenance data on each specific class of locomotive.

General information about the locomotive An overall description of the locomotive and its' systems Types of equipment applied to the locomotive Capacities of systems such as fuel and lube oil Weights of major components The information contained in Section 0 will be used on a daily basis. For example, you need to know what the cooling system capacity is when refilling after repairs or when calculating water treatment chemicals. Component weights are required when performing repairs or for selecting proper lifting equipment.

Sample Section "2" - Fuel System Section 2 is a typical service section, dealing with the fuel system. Each of these sections begins with a system description, which explains the operation of the system, and describes the major components. Generally, a diagram of the system is shown, to aid in understanding how the system functions, and to assist in troubleshooting. From there, the section describes each major component in detail. Specific maintenance requirements, specifications, and procedures are provided. For example, on page 2 of section 2, the cleaning procedure for the fuel suction strainer is given. A brush can be used to clean the element and a wooden dowel is used to spread the pleats. It also states that the engine must be shut down to perform this servicing procedure. Section 2 provides additional information on the proper storage and handling of fuel for the locomotive.

The last part of the section provides a list of references that you can consult if you need additional information. Section 2 states that you could look in M.I. 4110 (Maintenance Instruction) to find additional information on maintenance of the fuel pump. If special tools or equipment are required for servicing the system, you can find them listed on these pages.

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All of the sections in the Locomotive Service manual are arranged the same way:

General system description System diagram Specific service requirements and procedures References, and Special tools and part numbers

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Again, if you know the specific system that you require information about, consult the index for the section of the manual that covers that system.

Engine Maintenance Manual (EMM) The Engine Maintenance Manual is prepared for the specific engine in each order of locomotives. While most information applies to all G M diesel engines, there may be certain items specific to each order. Always ensure that you are using the correct manual for your engines. The manual is broken down into sections much like the Locomotive Service Manual. The page numbers work the same way, the first number refers to the section, the second number is the specific section page. In this manual, however, you can see that there is a table of contents for each section to help you find the information you need quickly.

Section ”0”-Table of Contents Section 0 again provides general service information on the engine and it’s systems. It also gives a description of engine operation, specifically the operating cycle of the G M engine. This information will be covered in more detail elsewhere in the course. Section 0 gives engine specifications, ratings and speeds, and specific equipment applied to the engine. For example a Woodward PGR governor has been applied to this engine and at full speed engine RPM should be 904. Also contained in this section is a weight list for engine components similar to the Locomotive Service Manual. O n page 0-9 can be found a complete listing of torque values for your engine. The torque specifications also may include special instruction as denoted by an asterisk -(*):’The asterisk (*) means that you have to look at the end of the section for more information. Refer to the Table of Contents for Section 1.

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311 The table of contents serves as a quick guide to the particular information you need. Section 1 is a typical service section that deals with the crankcase and associated parts. As in the L.S.M., the section starts off with a general description, and then deals with specific components one by one. For each component, a detailed description is provided along with specific inspection and repair procedures. To further understand the layout of the manual, refer to the pages dealing with the lower liner bore insert (p. 1-2). Along with a description of the component, removal and application procedures are described.

The manual tells us if special tools are required to perform the indicated tasks, and in this case a puller is needed to remove and apply the insert. The special tools, such as the puller, are fully described, and drawings provided should it be necessary to fabricate these tools.

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Section 1 finishes with a list of references, specifications for the assemblies, and a list of special tools required for repair of components covered in this section. All the remaining sections of the Engine Service Manual are organized in a similar manner.

Review The Locomotive Service Manual deals with systems and components found on the locomotive except for the diesel engine.

The diesel engine is covered separately in the Engine Service Manual. Both manuals are arranged in the same manner, sections that deal with a specific subject. Within the section, the first number on the bottom of the page refers to the section, while the second number is the specific page within the section. Each section starts with a description of the system or component. Specific maintenance procedures for each component are dealt with, and at the back of each section may be found:

Service references Specifications Special tools and, sometimes part numbers

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Maintenance Instructions (MI'S) Maintenance Instructions, or MI'S, are another form of technical publication produced by General Motors. MI'S deal with the service and repair of specific systems and/or components. These documents are produced as required when:

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Information in the Service Manuals has been updated

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Or when more detailed information is required for inspection or repair of systems or components

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information it contains.

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The number of the MI can be found on the top right corner of the first page (MI-1520). Beneath the number sometimes will be found Rev. and a letter signifyirig the latest update. If you have two versions of an MI, use the version with the latest revision letter. MI-1 520 shows Rev A, meaning that it has been updated once since it was first published.

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Example MI 1520

The title on the top of the first page describes the subject dealt with by the MI, in this case, the inspection and repair of traction motor gear cases. While each MI deals with a different subject, they all follow a similar layout. The subject of the MI is first reviewed, followed by a brief description of the component or system involved. For example, M.I. 1520 explains the functions of the traction motor gear case (Protects the traction motor gears from dirt and/or damage, and contains the gear lubricant). Next, the procedures for removal, inspection, repair, and application are covered in detail. Detailed drawings are provided as required to explain the procedures, fabricate tools, or modify components. The MI also lists other references when required, part numbers for original and replacement parts, and special tools or equipment needed to perform the task. There are numerous MI'S on a great variety of subjects and an index of current MI'S has been prepared to assist in finding information. This index allows you to find MI numbers by subject, number, or application.

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ITS Locomotive Training Series Student Text

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Review

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MI’Sare used to provide additional service data on components and/or systems. They are also used to update information contained in the ESM or LSM. MI’Swill also be used to provide service data on additional locomotive equipment or systems. Revisions to MI’Sare indicated by a revision letter under the MI number on the first page.

MI’Sare organized similar to the sections of the ESM and LSM: Beginning with a general description of the system or components involved Continuing with service data on inspection, repair, or replacement And finishing with a listing of references, specifications, and tools or special equipment required

Service Pointers Refer to the sample GM Pointer. GM Pointers are produced to update procedures or specifications of engine or locomotive systems/components. They are issued to customers as required, and are designed to get the information distributed as quickly as possible. GM Pointers are also used to provide customers with notice of changes to EMM,

LSM, or MI’S.

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Review Pointers are used to get information to the customers fast. They may contain changes to inspections, repair procedures, or specifications. They may also be used simply to advise customers of revisions to technical documents. Pointers may deal with one or more subjects.

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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Diesel Engine Theory

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Introduction In this chapter we will look at the diesel engine beginning with a review of the four stroke and two stroke operating cycles. In this chapter we will continue with:

general engine arrangement; model types (8,12,16, and 20 cylinders,); internal pressure zones (crankcase, airbox, and top deck,) serial number locations and system

ElectrMotive 567,645and 710 Diesel Engines are all "twostroke" engines.

In the next chapter we will cover the individual components in detail.

Engine Operating Cycles The General Motors diesel engine utilizes a two stroke operating cycle. This means that for one engine cylinder to generate a power pulse, it requires two strokes of the piston, one upwards stroke and one downwards stroke. The easiest way to present this cycle is by first comparing it to the four stroke cycle used in most other diesel engines.

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IT5 Locomotive Training Series Student Text

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Four Stroke Engine Construction

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Fuel Injector

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Most four stroke diesel engines share a similar construction (Figure 2.1). The cylinder is closed on the top by the cylinder head and sealed on the bottom by the moveable piston and piston rings. Intake and exhaust valves located in the cylinder head allow the flow of gases into and out of the cylinder as required. The crankshaft eccentric and the connecting rod translate the up and down motion of the piston to a rotary motion on the shaft.

Intake Valve

Exhaust Valve

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3 3 Cylinder

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Crankshaft

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Figure 2.1 Four Stroke Construction

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The four stroke cycle begins with the intake stroke (Figure 2.2). The rotary motion of the crankshaft causes the piston in the cylinder to move downwards, increasing the volume of the cylinder. As the volume of the cylinder increases, the pressure decreases below atmospheric pressure.

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Four Stroke Engine Intake Stroke

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Fresh air enters Cylinder through Intake valve

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Fresh air at the higher pressure rushes into the cylinder through the open intake valve to fill the cylinder. This provides a new charge of oxygen,for the combustion of the fuel.

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As the piston approaches the bottom of the stroke (BottomDead Center or BDC), the intake valve closes to seal the cylinder. The piston now begins to move upwards on the compression stroke.

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I Figure 2.2 Intake Stroke

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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Four Stroke Engine - Compression Stroke As the piston moves upwards on the compression stroke (Figure 2.3), the volume of the sealed cylinder is reduced and causes the pressure in the cylinder to rapidly increase. The reduction in cylinder volume is usually expressed as the compression ratio. This ratio is the difference between the cylinder volume with the piston at Bottom Dead Center (BDC) and cylinder volume with the piston at Top Dead Center (TDC). Diesel engines commonly have compression ratios between 16:l and 20:l.

It is a property of gases, that as the pressure is increased the temperature also increases. It is this rapid increase in temperature that provides the heat necessary to ignite the fuel.

Four Stroke Engine - Power Stroke a

The piston moves upwards on the

compression stroke increasing cylinder pressure and temperature. Near the top of this stroke, fuel is sprayed into the cylinder by the fuel injector. The fuel is atomized by the injector so that it will mix easily and completely with the hot air. The high cylinder temperature ignites the fuel and air mixture and combustion begins.

Figure 2.3 Compression Stroke

Fuel enters Cylinder through Injector

The heat produced by the burning fuel and air mixture causes a further rapid increase in cylinder pressure. As the piston passes through Top Dead Center and begins a downward motion, the increased cylinder pressure pushes the piston down. The force acting downwards on the piston is many times greater than the force required to initially compress the air. This force is transferred through the connecting rod to the crankshaft. It is through the actions of the cylinder assembly that the latent energy contained in the fuel is released and converted into a useable mechanical force.

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Figure 2.4 Power Stroke

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Four Stroke Engine - Exhaust Stroke

Burnt Gases pushed out Exhaust Valve

Before the combustion process can be repeated, the cylinder must be purged of the burnt gases and refilled with a fresh air charge.

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Just before the piston reaches the bottom of the power stroke, the exhaust valve is opened to vent the pressure contained in the cylinder. The piston passes Bottom Dead Center and moves upwards on the exhaust stroke. The motion of the piston moving upwards reduces the volume of the cylinder and increases the pressure.

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Since the exhaust valve is open, the burnt gases flow outwards to the atmosphere through the valve. When the piston has reached Top Dead Center, the exhaust valve closes, the intake valve opens, and the cylinder is ready to begin the next intake stroke.

Figure 2.5 Exhaust Stroke

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Four Stroke Engine - Conclusion In order for the four stroke engine to produce one power stroke, four distinct piston movements are required: intake (piston moves downwards) compression (piston moves upwards) power (piston moves downwards) exhaust (piston moves upwards)

The crankshaft must turn two complete revolutions to produce these for motions. Therefore each cylinder of a four stroke engine will produce one power stroke every other revolution of the crankshaft. The valve operating mechanism (usually a camshaft) will operate at one half of crankshaft speed in a four stroke engine. The energy generated on the power stroke is transferred to the crankshaft and then to the devices powered by the engine. Some of the energy produced is absorbed by the heavy flywheel, usually mounted on the rear of the crank. This energy is released as momentum to carry the engine through the exhaust, intake, and compression strokes. 2-4

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Electro-Motive Model 567, 645 & 710 Series Diesel Engines

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Two Stroke Engine Construction

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Fuel Injector

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There are a great many different designs for two stroke (or cycle) engines; this text will deal only with the design similar to the one used on the General Motors diesel engines.

(air pump)

As in the four stroke engine, the cylinder assembly is sealed at the top by the cylinder head, and at the bottom by the piston and piston rings. Fuel is injected in a similar manner by a fuel injector located in the cylinder head. There are however several very important differences. Instead of utilizing an intake valve located in the cylinder head, a row of ports, or openings, have been located in the lower portion of the cylinder wall. These ports are surrounded by a chamber known commonly as the airbox. Figure 2.6 Two Stroke Engine Constnrction

Fresh air is pumped into this chamber by an air pump, or blower, for use in combustion.

Two Stroke Engine Scavenging (Start) The two stroke engine uses a different method of introducing a fresh air charge into the cylinder than the four stroke engine. Rotation of the crankshaft causes the mechanically coupled air pump to force fresh air into the airbox that surrounds the air ports on the lower cylinder walls. With the piston at the bottom of the stroke, this fresh air enters the cylinder through the ports. As the exhaust valves are also open at this time, the air moves upwards through the cylinder, and exits through the open valves. ~

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IG Figure 2.7 Scavenging (Start)

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The air ports are angled slightly from the center line of the cylinder causing the air to swirl in the cylinder as it moves upwards. Thus the cylinder is completely purged and filled with fresh air. This action is called scavenging.

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Two Stroke Engine Scavenging (Fin ish) The crankshaft rotates, moving the piston upwards in the cylinder. The upwards piston movement blocks the flow of fresh air through the liner ports, and forces a small amount of air out the exhaust valves. Any remaining exhaust from the previous power stroke is completely removed from the cylinder by this action.

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The exhaust valves then close to seal the cylinder and allow compression of the air.

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Figure 2.8 Scavenging (Finish)

Two Stroke Engine - Compression After the exhaust valves have closed, the piston moves upwards compressing the air in the cylinder. As in the four stroke engine when the air is compressed, the temperature and pressure rise. However, compression in a two stroke engine differs slightly in that the initial cylinder pressure is slightly higher because of the air pump, and the effective stroke is much shorter.

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Figure 2.9 Compression Stroke

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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Two Stroke Engine - Injection

Fuel Injection begins just before TDC

The injection of fuel into the cylinder of the two stroke engine is handled in the same manner as the four stroke engine. r\s the piston nears Top Dead Center (TDC)the fuel injector delivers an atomized spray of fuel into the cylinder.

The fuel combines with the air and is ignited by the high temperature. Rotation of the crankshaft carries the piston past TDC as the fuel begins to combust with the air.

Two Stroke Engine - Power

Figure 2.10 Injection Stroke

Combustion of the fuel and air causes the pressure in the cylinder to rise rapidly. This pressure expands in all directions, pushing the piston downwards with a greater force than it took to initially compress the air. As in the four stroke engine, this force on the piston is converted into a rotary motion on the crankshaft, providing a useable mechanical force.

Figure2.11 Power Stroke IlS Locomotive Training Series - Student Text

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Two Stroke Engine Exhaust

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The piston travels downwards on the power stroke until a point just before the air ports are uncovered. The exhaust valves open to vent cylinder pressure to atmosphere.

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By opening the exhaust valves slightly before the air ports, a flow of gasses is started through the valves and cylinder pressure is reduced below that of the airbox. By reducing cylinder pressure in this way a back flow of gas (backfire) into the airbox is prevented. Cylinder pressure continues to reduce until the air ports are opened by the piston. At this time the fresh air from the airbox is allowed to enter and scavenge the cylinder to begin the cycle again.

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4 Figure 2.12 Exhaust Stroke

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Two Stroke Engine Conclusion Conversion of the heat energy contained in the fuel is essentially done the same way in both the two and four stroke engines. However where the four stroke engine requires two revolutions of the crankshaft to deliver one power impulse, the two stroke engine will deliver one power impulse every crankshaft revolution.

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The power impulses in the two stroke engine are of a less magnitude than a four stoke due to the reduced effective compression and power strokes.

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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The four stroke engine cycle consists of intake, compression, power, and exhaust.

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Fuel is injected into a closed cylinder containing compressed air at a temperature high enough to ignite the fuel.

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The pressure increase in the cylinder due to the expanding gases forces the piston downwards inducing a turning motion on the crankshaft.

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The four stroke engine requires two complete revolutions of the crankshaft to produce one power impulse.

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The two stroke engine uses air ports located around the lower portion of the cylinder liner instead of intake valves to admit fresh air into the cylinder.

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Fresh air supplied by an air pump is used for combustion and to purge (scavenge) the cylinder of exhaust gases. The two stroke engine requires one complete revolution of the crankshaft to produce one power impulse.

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ITS LocomotiveTraining Series - Student Text

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General Engine Arrangement

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The two stroke General Motors diesel engine is a It Narrow 'V' type design consisting of two banks (or rows) of engine cylinders arranged with an angle of 45 0 between them. Opposing cylinders share a common crankshaft eccentric (throw)using a "fork and blade" connecting rod design. This design allows for a close distance between cylinders, and the narrow "V", keeps the overall engine width to a minimum. The engine is available in 8, 12, 16, and 20 cylinder models, depending on the desired horsepower output. The 45" compact nature of this engine makes it particularly Between Banks suited to railroad locomotives and marine installations where size is a major consideration.

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The rear of the engine is usually called the flywheel end since this is where the main generator is driven from. Depending on equipment and horsepower, it may also be termed the blower or turbo end because combustion air is supplied through the rear of the engine by either a mechanical air blower or a turbocharger.

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The camshaft gear train and auxiliary

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generator drive are located on the rear of the engine. Engine rotation is left hand, or anticlockwise as viewed from the rear facing towards the front.

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The front end of the engine is commonly referred to as the governor end as this is the mounting location of this device. The water pumps, lube oil pumps, and the pump drive gears are also located on the front of the engine. All oil, fuel, and cooling water connections for the engine are made on the front end. Since the size and type of pumps may vary according to engine horsepower and engine application, the front is sometimes referred to as the accessory end. A drive connection is available on the front end of the crankshaft for accessory items such as air compressors, additional pumps, or mechanically driven blowers.

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Figure 2.14 Engine Configuration

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Electro-Motive Model 567.645 & 710 Series Diesel Engines

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Engine orientation is established from the rear of the engine looking forward.

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The engine banks are termed left and right as viewed from the rear of the engine looking forward. The cylinders are numbered sequentially from front to rear beginning with the right bank. Cylinder number one is always located on the right front corner of the engine.

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In the illustration of a twelve cylinder engine Figure 2.14, the cylinders on the right bank are numbered one thru six; the cylinders on the left bank are numbered seven thru twelve. O n a sixteen cylinder engine the cylinders on the right bank are numbered one thru eight beginning with the right front; the cylinders on the left bank are numbered nine thru sixteen beginning with the left front.

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Cylinder number one on all engines is at TDC when the flywheel pointer reads 0". The cylinder mated to number one will be at TDC 45" later because of the layout of the cylinder banks. Therefore, paired engine cylinders, such as number one and seven on the twelve cylinder model, always fire 45" apart. O n the eight cylinder engine, a power pulse is generated every 45" of crankshaft rotation (360" I 8 cyl = 45"). The sixteen cylinder engine generates a power pulse every 22 1/2" of crankshaft rotation (360" I 16 cyI = 22 I/2").These two engines have a "Balanced" firing order since the pulses are evenly distributed through out one crankshaft revolution.

The twelve and twenty cylinder models have an "Unbalanced" firing order. To balance these engines is not possible with a 45" vee. For example, the twelve cylinder model would require a power pulse every 30" (360" I 12 cyl = 30"). This is not possible since opposing cylinders are 45" apart. The "Pairs" of cylinders are distributed through

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out the revolution based on experience and computer simulation to give the best performance for the twelve and twenty cylinder models. An Injector Timing tag is located at the rear corner of the engine for use when doing engine adjustments.

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NOTE: Always consult your Engine Maintenance Manual for the correct firing order and timing for the engine being serviced !

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The exhaust system is located on the top of the engine between the cylinder banks. For engines equipped with mechanical blowers, the exhaust is collected in the manifold and allowed to vent to atmosphere. O n higher horsepower engines equipped with turbochargers, the exhaust is collected in the manifold and sent through the turbine before escaping to atmosphere.

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The GM diesel engine is a 45" "narrow V" design.

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Engine layout is determined from the rear of the engine facing forward.

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The combustion air supply (bloweror turbo), camshaft gear train, and generator drives are located on the rear of the engine.

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The engine consists of two banks (or rows) of cylinders, the left bank and the right bank.

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64 The cylinders are numbered from front to rear, beginning with the right front cylinder.

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Opposing cylinders are always timed 45" apart.

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The front end of the engine is also called the governor or accessory end.

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The governor, water pumps, and lube oil pumps are located on the front of the engine. All fuel, oil, and cooling water connections are made at the front of the engine.

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3 The exhaust system is mounted to the top of the engine between the cylinder banks.

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ElectroMotiveModel 567, 645 & 710 Series Diesel Engines

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Internal Pressure Divisions The GM diesel engine is divided into two distinct pressure zones; positive pressure (above atmospheric pressure);and negative pressure (be2ow atmospheric pressure).

Positive Pressure The airbox area of the engine is always at a positive pressure as compared to atmosphere. The positive pressure is required to force the air into the cylinders through the liner air ports. The in flowing air must have sufficient pressure to push through the cylinder and force the burnt gases out the exhaust valves. Unlike the four stroke engine, there is no intake stroke to draw fresh air into the cylinder, nor an exhaust stroke to expel the burnt gases.

Figure 2.15 Positive Pressure Zone

The positive air pressure in the airbox is sometimes referred to as the boost pressure. The amount of boost pressure on a mechanical blower equipped engine is directly proportional to the speed of the blower (engine speed). O n turbo equipped engines, the boost depends not only on engine speed, but also the amount of fuel consumed by the engine, as the turbo relies on waste heat energy in the exhaust to operate.

Negative Pressure Most engines use a crankcase ventilation system to prevent the buildup of combustible gases in the crankcase. The eductor system on the GM engine is designed to keep the crankcase at a negative pressure whenever the engine is running. Blower equipped engines draw the crankcase vapours through an oil separator into the blower inlet. Turbo equipped engine use an eductor (venturi) tube in the exhaust stack to draw the vapours through the oil separator and expel them to atmosphere. Figure 2.16 Negutive Pressure Zone

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Positive Pressure

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3 The oil separator is designed to trap and recover small oil droplets carried out of the engine with the vapours.

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The top deck area of the engine is common to the engine sump through oil drain tubes, and the entire assembly is kept at the negative pressure. The reduction of pressure is dependant on engine speed and engine condition. As engine speed is increased, the vapour withdrawn is also increased. Leakage on engine covers and seals or excessive piston ring leakage (blowby) will affect the ability of the system to maintain the negative pressure.

Serial Numbers Refer to section "0"of the Engine Maintenance Manual.

To facilitate parts identification most major components and assemblies are stamped with a part number and a unique serial number. In order to maintain the G M engine and ensure correct parts replacement, it is necessary to understand the system used for serial numbers. Section 0 of the Engine Maintenance Manual identifies most parts that carry serial numbers and where the number is located.

The following example shows the type of information typically found on the Serial Number & Identification plate found on the right bank of the crankcase. a) b) c) d)

ELECTRO-MOTIVE DIVISION GENERAL MOTORS CORPORATION LAGRANGE, IL 60526

SERIAL NO.

MODEL NO.

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Figure 2.17 Engine ldentification Plate

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model designation date of manufacture (or remanufacture) location of manufacture production sequence number

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Electro-Motive Model 567, 645 & 710 Series Diesel Engines

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The specific breakdown of the data is as follows:

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Number of cylinders ( 8, 12,16, or 20)

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Cubic inch displacement per cylinder ( 567,645, or 710) (9291.4, 10,569.6, 11,634.8)-CM3

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(3)(4)Application ( 567A thru E, 645 E thru F, 710 G)

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New Generation Fuel Economy Engine (designated B or C )

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Year produced Month produced ( A thru M, Z is skipped due to confusion)

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Engine history

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Railroad engine blower equipped Industrial engine blower equipped Marine engine blower equipped (without strainer housing) Railroad engine turbocharged Industrial power generator Marine engine turbocharged (without struiner housing) Marine engine blower equipped (with strainer housing) Marine engine turbocharged (with strainer housing) Drill rig engine blower equipped Drill rig engine turbocharged Industrial engine turbocharged

(9)

New manufacture Remanufactured trade in UTEX (unit exchange) Repair and return

Location of production

1 2 3 4

5 6 7

LaGrange, 11. not used Hazelwood, Mo. (no longer used) Vendoritem Halethorpe, Md. (turbo) Commerce, Ca. (turbo) Jacksonville, F1.

(10) Production sequence number In addition to the engine itself, all major components and assemblies carry a serial number. While it is possible for two parts to have identical serial numbers, it is not possible for two parts to have both the same serial number and the same part number. For example, while you may have a cylinder head and a cylinder liner with the same serial numbers, it is impossible to have two cylinder heads with the same serial numbers.

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Review The diesel engine and all major components and assemblies are identified with part numbers and unique serial numbers.

The serial number provides a history of the engine or component including date

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and location of manufacture.

The diesel engine identification tag is located on the right bank of the engine It is not possible to have two identical parts with the same serial number.

The first two digits of the serial number indicate the year of production. Months of manufacture are expressed as A thru M; I is excluded due to confusion.

The last three digits of the serial number indicate the production sequence number.

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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Engine Components & Construction

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Physical Layout The GM 567,645 and 710 Diesel engines are of a "V" design, and are manufactured in 8, 12, 16 and 20 cylinder models. Most engines use a left hand (or counterclockwise)rotation, as viewed from the rear, or flywheel end. Some marin applications use a right hand (clockwise)rotation engine paired with a left hand rotation engine so the propellers will spin in opposite directions. Others use a right and left rotation engine coupled to each side of a common gearbox to turn a single propshaft. The camshaft gear train and turbocharger or rootes blower are located on the rear of the engine. The governor, oil pumps, water pumps, and strainer housing are located on the front, or accessory end of the engine. An important point is that the engine is mounted backwards in the locomotive, the rear of the engine faces the front of the locomotive.

The engine is arranged into pairs of cylinders, each pair using a common throw on the crankshaft. The cylinders are divided into two banks, left and right. If you view the engine from the rear facing towards the governor, or accessory end, the left bank is on the left side, and the right bank is on the right side.

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ITS LocomotiveTraining Series Student Text

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3 On a 16 cylinder engine, for instance, the cylinders are numbered one to eight on the right bank, starting with the front right. On the left bank of the engine the cylinders are numbered nine to sixteen, starting with the front left. This gives us pairs of cylinders such as 1 and 9,8 and 16. Opposing cylinders fire 45 degrees of crankshaft rotation apart due to the 45 degree "v"layout of the engine. A 16 cylinder engine has one cylinder firing every 22 -1/2 degrees of crankshaft rotation (360/16).Since the timing between each power pulse is equal (22 1/2 degrees), the 16 cylinder engine has a balanced firing order. The firing order for a 16 cylinder example engine is 1,8,9, 16, 3,6, 11, 14,4, 5, 12,13, 2,7,10, 15.

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22-1/2"

22-1/20 45" 67- 1/2"

90" 112-1/20 135" 157-1/2" 180" 202-1/20 225" 247-312" 270"

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9 On 12 and 20 cylinder engines, the firing order is unbalanced, with an unequal number of degrees of crankshaft rotation between power pulses. T o have a balanced firing order, a 20 cylinder engine would need a power pulse every 18 degrees, and a 12 cylinder every 30 degrees, both of which are not practical due to the 45 degree "V" arrangement.The following charts show the firing order and top dead center for 12 and 20 cylinder left hand rotation engines.

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0" 9" 36" 45" 72" 81" 108" 117O 144" 153" 180" 189" 216" 225" 252" 261" 288" 297" 324"

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On the 12 cylinder 710 engine, the firing order has been changed in an effort to smooth out the torsional vibrations caused by the unbalanced firing order of previous engines. This is made possible by using a different crankshaft and camshafts along with a specially tuned pendulum trpe torsional damper. The following is the firing order / top dead center chart for the 12N left hand rotation engine for comparison to the 12 cylinder chart on the previous page. The 12N engine is only available in left hand rotation versions.

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NOTE: Always consult your Engine Maintenance Manual for the correct firing order and timing of your engine. This information may be found in Section 0 of the EMM.

IlS Locomotive Training Series -Student Text

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567 645 - 710 Engine Evolution

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MODEL

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# CYLS

16CYL H.P. IMPROVEMENTS

Top Deck Cover

Exhaust Valve Rocker A n

Camshaft injector Rocker A n

E x h m v.hn, Bridge

OVemPOSd Trip Shoe

Exhawt Valve Spring

F d Manifold

Exhaust Valve

Injector control Shafl Cylinder Head

Injaater Rack

Piaton

Cylinder Test Valve

ThM WMher Fuel injector

PMon Carrier

Cylinder Head Crab Bon

Piaton Pin

Air inlel Porn

Cnnkcuo Cyl1nd.r Liner

Air Box

Blade Connecting Rod

Water inlet Jumper

Oil Drain M d V M '

Water Inla MMlfold

Air Box Handhola Cover

Main Lube Oil Manifold

Piston Cooling Oil Plpe Fork CoMlectlng Rod

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Piaon Cooling

Conwcllng Rod B ~ l u t

Oil Manifold

Main Beating 'A' Frame

oil PMl

Handhole Cowr

Mdn Bearing Cap

oil P M

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Oil Pan Sump

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Figure 3.1 Cross Sectional Engine Diagram

mWAmR mMLa 645 SERIES DIESEL ENGINE

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ElectroMotive Model 567.645 & 710 Series Diesel Engines

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Components

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In this section we will look at the major components of the diesel engine, their function and location. This section is intended to aid in identification of engine components and systems. Repair and inspection is covered in the engine maintenance manual, maintenance instructions documents and in subsequent training manuals.

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Crankcase The main structural component of the engine is the crankcase or engine block as shown in Figure 3.2 below.

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Figure 3.2 Engine Block

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ITS Locomotive Training Series -Student Text

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Figure 3.3 Airbox Section (Left) and Airbox Sections in 45 Degree "V" (Right)

The engine block is constructed from four lengths of channel welded together to form the 45 degree air box as illustrated in Figure 3.3. The two air box sections then have a tie plate added at the top and a curved plate added in the "V" to form the main oil gallery. Power pack retainers, base rails and " A frames are added to complete the inner air box assembly as shown in Figure 3.4.

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Power Pack Retainers

Tie Plate

curved Plat

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Figure 3.4 Airbox Sub-assembly (Left) and Completed Airbox Assembly (Right)

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Figure 3.5 illustrates the application of the remainder of the items such as side cover plates, crab supports, cylinder test valve retainers, etc., to complete the construction of the crankcase or engine block. The completed assembly is then measured to ensure there is enough material for the machining processes. The engine block is then heated to between 1050°F and 1200°F to relieve any stress from welding. After being allowed to cool, the block is peened with steel shot, then sent for machining. The block supports the power assemblies and crankshaft, and serves as a mounting for accessories such as the oil pumps, turbocharger, etc. It is the main structural component of the engine, everything else is attached to it.

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ElectroMotiveModel 567,645 & 710 Series Diesel Engines

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Top Deck

Upper Water Manifold

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Mainframe Member

Figure 3.5 Completed Crankcase Assembly

This engine is called a dry block design, because the engine coolant circulates through water jackets built into the individual cylinder liners. Earlier engines (567UV, 5674 and 567B) used "water decks'' and O-rings on the liners and cylinder heads to contain the engine coolant. Discharge Water Manitold

I r Water Manifold

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niet Water Manifold

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Figure 3.6 567 W ,5674 abd 567B Block Cross Section

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Cylinder bores on opposite banks use the same centre line because they share one throw of the crankshaft. This feature allows for a relatively compact design. Exhaust passages are built in to carry the exhaust gasses from the cylinder heads to the exhaust manifold. The crankcase assembly has handholes to allow inspection and servicing of components in the airbox surrounding the cylinder liners. O n the underside of the crankcase are A-frames which form the main bearing supports for the crankshaft. Above the A-frames is a standpipe running the full length of the engine which provides a passage for main bearing lubrication. O n each side of the crankcase are located piston cooling manifolds that deliver oil to the underside of each cylinder assembly. Base rails along each side of the crankcase allow for mounting of the oil pan.

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CRANKCASE COMPARISON

567 - 645 Comparison Crankcase Construction A-Frame Attachment Weld Sizes

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567C and Earlier 114" 5670 and early 645E 318" 645E, I968 and later 112" 645E, serial ## starting with 1971 "D" and later (heavy "A" frame) shown below

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31 Figure 3.7 "A"-FrameWeld Locations

CRANKCASE'A' FRAME SIDE VIEWS

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Figure 3.8 "A" Frame Configurations

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NEW HEAW 'A' W E (71D QuuAnd On)

ElectrMotive Model 567,645 & 710 Series Diesel Engines

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645E - 645F Comparison

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645F, 1977, legs extended through base rail and welded on both sides (shown Below)

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thicker base rail and top deck plate

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E CRANKCASE

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F CRANKCASE

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Figure 3.9 645E and 6453 Crankcase Comparison

645F - 710 Comparison

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(+28.45mm)

710G, A frame attachment same as 645F

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Note: Additional improvements to the "G" case:

1" larger main bearing bore and cap 1.5" taller head retainer forging Improved head retainer to caseceld 1/16" thicker side sheets 1.62" taller and 1.12" wider than "F"

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Figure 3.10 645 - 710 Crankcase Comparison

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ITS Locomotive Training Series - Student Text

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Main Bearings and Crankshaft

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The next components to be covered are the main bearings and crankshaft. Figure 3.6 shows a typical main bearing application.

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During final machining of the crankcase, all main bearing caps are installed, and the main bearings are line bored; serial numbers are stamped on both the “A” frames and bearing caps on the right side, including position number.

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The bearing caps are not interchangeable between positions or engines.

u Figure 3.1 1 Main Bearings

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You can see from this illustration that the main bearing caps are held in place by studs with nuts on the top and bottom.

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The top nuts (culled D nuts) are shaped to fit into recesses in the top of the “ A frame; this prevents them from turning. The studs have a hole drilled through the top; a retainer clip is inserted through this hole and mates with a slot in the top of the D nut to lock the stud and nut together. A special nut and hardened washer complete the bottom of the assembly. Newer 710 engines, due to a new machining process, use an automotive style main bearing cap retaining system. Threads are cut in the “A”frame and the main bearing caps are held in place with cap screws.

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The bearing itself is in two parts, an upper insert and a lower insert, the bearing is a steel backed bronze bearing with a leadkin (babbitt)overlay called a tri-metal bearing. The bearing is prevented from turning in the bore by tangs that fit into recesses in the “Kframe and bearing cap. The bearings can be replaced with the crankshaft in the engine by rotating the engine opposite to normal rotation. The upper and lower inserts are not interchangeable. Excessive longitudinal movement of the crankshaft is controlled by thrust collars located on the #3 main bearing of the 8 cylinder engine, #3 on the 12 cylinder, #5 and #6 on the 16 cylinder and #6 and #7 on the 20 cylinder.

Oil passages are drilled through the “A” frames up into the oil gallery to provide main bearing lubrication. A stand pipe protrudes up into the oil gallery from each of these passages to reduce dirt migration to the main bearings by taking the supply from the middle of the gallery instead of the bottom.

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3-10

Electro-tvlotive Model 567,645& 710 Series Diesel Engines

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Crankshaft The crankshaft as shown in Figure 3.12 is a drop forged carbon steel assembly with induction hardened journals (mainand throws). In the 16 and 20 cylinder engines, the shaft is in two parts, bolted together between the #5 & 6 main bearings on the 16 cylinder and #6 & 7 on the 20 cylinder.

Figure 3.12 Crankshafts

Crankshafts are dynamically balanced, by using counterweights, which compensate for the rotating mass of the crankpin and lower part of the connecting rod. Oil passages (Figure3.13) are drilled in the shaft to allow oil from the main bearings to lubricate the lower connecting rod bearings.

Figure 3.13 Oil Passages

ITS LocomotiveTraining Series - Student Text

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3 The ring gear and coupling disc bolted to the rear of the crankshaft provides the coupling for the generator, ring gear for engagement of the starting motors and holes for an engine turning bar to manually rotate the crankshaft. Degree and top dead center markings are stamped on the outer rim of the coupling disc for reference during maintenance procedures.

Figure 3.14 Ring Gear and Coupling Disc

O n some stationary and marine engine applications where there is no generator, a heavy flywheel is fitted to the rear of the engine. O n generator applications, the flywheel effect is provided by the weight of the main generator rotor.

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Torsional Dampers

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A torsional damper,

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(sometimes called harmonic balancer) is applied to the front of the crankshaft, directly behind the accessory drive gear, to absorb crankshaft torsional vibrations. Four types of torsional dampers have been applied to EMD engines over the years, the spring pack type, gear w e , viscous damper, and the pendulum type.

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The spring pack torsional damper is used on all 567 engines and 6 4 5 blower engines only. There are two versiodj-the 3 pack and the 6 pack. The 6 pack damper is recommended as an upgrade for any engine using a 3 pack damper.

kb Figure 3.15 Harmonic Balancer and Accessory Drive Gear --’

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Electro-MotiveModel 567, 645 & 710 Series Diesel Engines

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Oil Passage

Spring Housing

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Spring Packs Spring Drive Pins Figure 3.16 Spring Pack Torsional Damper with Front Coupling Removed

Viscous Dampers have a hollow sealed housing with a heavy inner ring rotating freely in a thick silicone fluid to absorb torsional vibrations. These were applied to 645E3 turbo engines until 1978 and are no longer recommended for use as the silicone fluid deteriorates and solidifies after approximately 7 years.

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Symptoms of a failed viscous damper include broken water pump shafts, and severe vibration. Replace with gear type damper.

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Figure 3.17 Viscous Damper

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ITS Locomotive Training Series - Student Text

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3 Front Plate

intermediate

Spider

Rear Plate

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3 Figure 3.18 Gear Type Damper, Exploded View

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4 The gear type torsional damper is a hydraulic paddle wheel device that absorbs torsional vibrations by forcing engine lubricating oil from passages in the crankshaft through narrow passages in the damper.The front plate, intermediate ring and rear plate are cushioned from the spider which is attached to the crankshaft, by the engine lubricating oil. This damper requires no maintenance other than inspection at normal overhaul time, but should be checked for free movement at intervals specified in the applicable Schedualed Maintenance Program. This is done by removing the front crankcase handhole cover and rotating the damper about 10" in each direction. If the damper cannot be moved it should be removed and disassembled. The pendulum type torsional damper is used on the 12N engine only. It uses centrifugal "throw out" weights attached to a center hub to absorb the crankshaft torsional vibrations.

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Figure 3.18a Gear Type Damper

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ElectroMotive Model 567,645 81710 Series Diesel Engines

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Oil Pan The engine oil pan (Figure 3.19) encloses the lower part of the crankcase assembly, and serves as both a base for the engine and a storage sump for lubricating oil.

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Figure 3.19 Oil Pun (Sump)

Handholes are provided at each cylinder location for inspection and servicing of engine components. Tubes in the oil pan correspond with holes in the crankcase base rail, and serve as drains for the air boxes. The oil pan also provides for checking of the oil level with a bayonet type dipstick, and piping to drain the sump. The pan is fabricated from steel plating and bolts to the underside of the crankcase assembly.

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Standard Capacity Oil Pan

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TYPES OF OIL PANS

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scawhging oil Suctlon Line

Oil 8ump

apacity Oil Pan

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ITS Locomotive Training Series - Student Text

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3 Power Packs (Assemblies)

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Each cylinder of the diesel engine consists of a power pack or power assembly as shown in Figure 3.20 which is made up of the following parts: cylinder liner cylinder head piston and rings piston carrier assembly connecting rod assembly Depending on your railroads maintenance practices, the power assembly can be removed from the engine piece by piece, or as a complete unit.

Figure 3.20 Power Assembly

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Cylinder Liner

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The cylinder liner as shown in Figure 3.21 is a cast iron assembly with brazed on outer sleeves.

3 Pilot Stud

The unit comprises the cylinder itself, cylinder water jacket, and intake ports. The intake ports are arranged in a row around the circumference of the liner. This arrangement ensures complete cylinder scavenging. Coolant enters the liner from a water manifold in the airbox, through a water jumper, into a flanged connection on the front lower side of the liner. Inside the water inlet is a deflector that prevents erosion and cold spots on the liner.

WatWJacket

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Air Inlet Ports

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Water Inlet

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Figure 3.21 Cylinder Liner

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Electro-Motive Model 567, 645 & 710 Series Diesel Engines

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The coolant circulates through the lower liner,up passages between the ports, and then through the upper liner. From there, the coolant passes through 12 outlet ports on the top of the liner to the cylinder head. The discharge holes are counter bored to retain red silicone seals with white teflon heat dams. A copper head seal is used between the liner and cylinder head. Eight stud bolts are arranged around the top of the liner to retain the cylinder head. A special pilot stud is located at the 5 o'clock position to ensure proper gasket and head alignment. The liner serial number is stamped below the water inlet on the side of the liner. There are basically two main types of cylinder liner; cast iron and chrome. These terms refer the treatment of the cylinder walls. The cylinder may have either chrome plated cylinder walls to be used with cast iron piston rings, or laser hardened cast iron walls used with chrome rings. The type of liner applied is dependant on the type of service the engine is used for. Chrome liners are generally applied when the locomotive must burn high sulphur fuels because they are particularly resistant to corrosion.

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The inner surface of the cylinder can be inspected while installed in the engine by sighting through the airbox and intake ports with the piston at bottom dead centre.

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The cylinder liners also have seal grooves containing O-rings in the bottom area. These O-rings seal off the airbox from the crankcase and mate with a lower liner insert in the bottom of the airbox.Two types of lower liner seals are used, Viton and Polyacrylic rubber. Viton seals offer improved durability over polyacrylic rubber and are identified by two red stripes 1/2" wide. Polyacrilyc rubber seals can be used in the lower groove on all blower engines and in the top groove on all except EC, F, and FB engines. Viton seals are required in the lower groove on all turbo engines and the top groove on EC, F, and FB engines.

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The liner bore diameter is increased approximatly .010" in the port area to relieve piston ring tension as the rings pass the ports.

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Figure 3.22 Lower Liner Bore Insert

The lower liner insert is a cast iron, replacable, sacrificial wear surface that is press fit and removed from the engine block using special hydraulic equipment. The lower liner pilot area and O-rings wear away the inside diameter of the lower liner insert as a result of engine vibration and power assembly movement. Two types of lower liner inserts are in use, the phosphate coated insert used on the 567 up to 645EC engines and the nickel plated insert used on 645F to 710G engines. The nickel plated insert offers improved wear resistance. A .060" oversize diameter lower liner insert is available for use where the insert crankcase bore is out of specification, which allows the weld up and re-boring of the insert bore to be postponed.

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Piston and Rings The pistons in EMD engines (Figure 3.23) are a cast iron alloy, one piece symetrical design which may be either phosphate coated or tin plated depending on application. Pistons on 567 and 645 engines are phosphate coated, which is not a lubricant, but absorbs engine oil to provide a barrier of lubrication between the piston and liner.

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The 710 piston has a ,0007" to .0015" (.02 mm/.04 mm) tin plating applied from below the #4 ring land to the bottom of the piston. This was done because of the 20% higher thrust loads from increased connecting rod angularity. Tin plating also reduces liner scuffing and is an aid in the break in process.

Figure 3.23 Piston Cut-Away

Tin-plated pistons are also available for all types of 645 engines and are recommended as an upgrade for EB and later engines to reduce liner bore scuffing. The undercrown of the piston is cooled by lubricating oil supplied by the piston cooling section of the main lube oil pump to the piston cooling pipes. This oil circulates from the piston cooling pipes through the piston carrier to the fins in the undercrown area to remove combustion heat from the piston crown area. The piston has four compression rings (3 for 567 engines) on the upper portion to seal the cylinder from the crankcase.These rings are either ductile steel for use with chrome plated liners, or chrome plated for use with cast iron finished liners. The top ring for use in cast iron finished liners is usually stainless steel with chrome plated face and sides that is pre-stressed by shot peening to improve fatigue strength. The rings may be inspected through the airbox handhole with the piston positioned so the rings are visible in the intake ports. Two different sizes of ring belts (distunce from upper side of top piston ring to the top ofthe piston) have been used. Ring belt location affects timing. Blower type 645 pistons have a 3/4"ring belt width as do 645EB and later "fire ring" pistons. O n 64533 pistons the ring belt width is 1 1/4".

Ring

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100 Drain H& Surfaces

Figure 3.24 Tin Plated Piston 3-18

Electro-Motive Model 567,645 & 710 Series Diesel Engines

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Two oil control rings are positioned on the lower portion of the piston skirt to control liner lubrication and prevent excess oil consumption.

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Piston Carrier

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The piston rides on a "trunnion" type carrier assembly (Figure 3.25).The carrier is fitted inside the piston, and a thrust washer on top of the carrier allows the piston to rotate freely in the cylinder.

PISTON CARRIER Step to hold insert % ,

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The piston is Bearing Retainer Figure 3.25 Piston Carrier, Rocking pin retained by a large snap ring fitting into a groove in the lower inside piston skirt. The snap ring is not loaded during normal operation as the piston is driven downward with each power stroke. If an injector is cut out or a cylinder is not firing, the snap ring is loaded as it must pull the piston down.

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Figure 3.26 Piston Cooling Tube Assemblies

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ITS LocomotiveTraining Series - Student Text

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Two different types of piston pin-carrier combinations have been used, the plain bore type and the rocking pin b-pe. The plain bore piston pin is conventional shaped and uses a bearing insert retained in the carrier by tangs. Silver plated bearing inserts are used on 567 and 645 turbo applications and bronze lined inserts on 567 and 645 blower engines. The "rocking piston pin" is machined on two offset centers .030" (.76 cm)to produce mechanical separations between the pin and bearing insert alternating between the three bearing surfaces in the course of a power cycle. This creates a pumping action to circulate lubricating oil between the pin and bearing. The rocking pin bearing insert is retained by a bolt, locking clip and bearing retainer. O n engines later than 710G3B, the insert is retained by a larger bolt (5116)torqued to 30 ft. lbs. (41 Nm)with no locking clip.

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'Piston Cooling Pipe

Lubrication and cooling of the carriertpiston assembly is Figure 3.27 Piston Cooling Oil Flow handled by the piston cooling portion of the lube oil system. h o n g each side of the drankcase is the piston cooling manifold, which has small "peel' pipes for each cylinder.

As the pistontcarrier approaches the bottom of the stroke, oil from this pipe is directed through a passage in the carrier to the underside of the piston. This oil cools the piston and lubricates the assembly.

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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Connecting Rods

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The GM diesel engine uses an interlocking connecting rod design (Figure 3.28) to connect the power assemblies to the crankshaft.

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The connecting rods consist of fork rods, blade rods, basket halves, and a set of connecting rod lower bearings with the piston pins bolted directly to the connecting rods.

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Basket Bolts

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Figure 3.28 Connecting Rod Configuration

The connecting rod bearing is held in place by the basket assembly of the fork rod. Two dowels in the fork rod locate the upper bearing shell, and one dowel in the basket locates the lower bearing shell. This bearing is a two part, steel backed, lead bronze with a babbitt overlay similar in construction to the main bearings.

The blade rod slides back and forth on the back of the upper connecting rod bearing and is held in place by shoulders on the inside of the fork rod. On left hand rotation engines the fork rods are installed on the left bank of the engine with the dowel on the basket serrations facing outwards.The blade rods are installed on the right bank with the long "toe" facing inwards. This articulated design allows for two cylinders to share a common crank throw centerline, greatly reducing overall engine dimensions. The fork rod has serial numbers stamped in three places; both basket halves, and above the dowel on the fork rod itself. The blade rod serial number is stamped on the slipper foot opposite the long toe. Fork rods and baskets are not interchangeable, as they are line bored as an assembly.

A blue color on the sides and top of the blade rod slipper foot is a result of the hardening process, not a sign of overheating. No abrasive material should be used on the polished slipper foot surface of the blade rod. The hinge pin type basket halves and connecting rods on 567,567A, 567B, and 567BC engines are no longer sold or serviced. The recommended upgrade is to replace them with the 567C type piston, carrier, pin and connecting rod assembly. An upgrade for fork rods manufactured before 1972 is to machine off the saddle "earsll, which eliminates the potential for fatigue cracks in that area. This modification procedure is covered in EMD Pointers 6 - 1 1 - 73. ITS Locomotive Training Series -Student Text

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Cylinder Head The next component to be looked at is the cylinder head (Figure 3.29). The cylinder head is a cast iron component, with passages for coolant and exhaust gases. Four exhaust valves control the flow of gases from the cylinder, through the passages, into the exhaust runner in the crankcase. These valves are run in replaceable nitrided valve guides, and held in place by valve springs and keepers. Three basic types of exhaust valves have been used stellite, inconel, and heavy-head inconel. Stellite valves with double groove locks were originally used on the 567 engine but are no longer available. Inconel valves with single groove locks and part number stamped on the stem originally used on the 645 engine are also no longer available. Heavy-headed inconel valves, which are more durable, became the basic valve in 1979 are are retrofitable to all EMD engines. Different valve types may be mixed within low horsepower engines but not within individual cylinder heads. The bottom of the head; or fireface, forms the top of the cylinder and the mating surface with the top of the liner. The fireface has a machined suface called phonographic finish which aids in sealing the head to liner gasket. "Considerable research and development time has been spent on eliminating the main cylinder head problem, fireface cracking between the injector well and the valve seats from thermal fatigue." Fireface temperatures on the latest cylinder heads, (Diamond 6) have been reduced by the addition of internal cooling surface spines, improvement of water flow, and the reduction of fireface metal thickness. Twelve passages around the outer diameter of the fireface allow coolant to flow from the liner to the cylinder head. The coolant flows over the inside of the fireface, around the valve guide bores and injector well, and exits the head by a discharge elbow into the engine block. From there the coolant is collected from all cylinders and flows to the radiators.

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The top of the head is machined for mounting of the injector, rocker arm assembly, and power assembly hold down crabs. The fuel injector is held in the injector well by a hold down crab, and is clamped against a copper seal in the bottom of the well to prevent combustion/compression leakage from the cylinder. Figure 3.29 Cylinder Head Assembly, Exploded View

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ElectroMotiveModel 567,645 & 710 Series Diesel Engines

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The cylinder head also has a test valve passage that allows testing of firing pressures/ temperatures, and the expulsion of moisture from the cylinder prior to engine start up. The head is held in place by the 8 liner studs, hardened washers and lock nuts.

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Figure 3.30 Cylinder Test Valve

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The serial number of the head is stamped on the top face at the five o'clock position.

Rocker Arm Assembly The rocker arm assembly as shown in Figure 3.31, acts as an operating mechanism for the exhaust valves and fuel injector and is held in place by two studs on the top of the head. There are three rocker arms per cylinder; two exhaust and one injector (centre a m ) . Rollers on one end of the rocker arms follow lobes on the camshaft. Force from the camshaft is transmitted to the fuel injector, and to two valve bridges (one on each side of the injector). Each valve bridge has two hydraulic lash adjusters that open the exhaust valves and maintain proper valve adjustment.

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Figure 3.3 1 Rocker Ann Assembly ITS Locomotive Training Series -Student Text

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c) To check for a defective lash adjusters, hold your finger beside each adjuster on top of the valve collar. Any “pinching of the finger indicates a defective adjuster which should be changed.

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Valve Bridge

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Figure 3.32 Valve Bridge I Lash Adjuster Cross Sedion

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Hold Down Crab System The power assemblies are held in the engine block by means of a crab bolt retaining system. There have been changes to the system over the evolution of the EMD diesel engine which has resulted in there being two distinct systems in use. The standard crab system is shown in Figure 3.33, and the plate crab system as shown in Figure 3.34.

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Crab bolts extend upwards from inside the airbox to above the cylinder head retention pot. The underside of the hole in the airbox top plate has a spherical seat that mates with a similar surface near the head of the crab bolt. These surfaces seal off the airbox from the top deck of the engine to control leakage of air and oil.

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A plate with a retainer bolt is applied under the heads of the bolts to prevent them from turning, and from falling into the airbox while power assembly work is being done.

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The standard crab system is found on lower horsepower engines. This system uses an individual crab for each bolt. These crabs have a spherical seat which matches the shape of the crab nut.

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Electro-Motive Model 567,645 & 710 Serles Diesel Engines

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Figure 3.33 Standard Crab System

1. Crab Nut 5. Retainer Plate 2. Crab 6. Retainer Bolt 3. Crab Bolt 7. Retainer Bolt Nut 4. Cylinder Head

With the plate crab system, the plate is fit onto the crab studs over two adjacent cylinder heads, or in the case of end cylinders, the head and special lugs on the crankcase. T h e plates have spherical recesses around the crab bolts that match with the similar surfaces on hardened steel washers. Specially designed crab nuts thread onto the studs and hold the power assemblies secure.

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Figure 3.34 Plate Crab System

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1. Crab Nut 2. Hardened Washer 3. Crab 4. Crab Bolt

5. Cylinder Head 6. Retainer Bolt Nut 7. Retainer Plate 8. Retainer Bolt

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Between the cylinder head lower surface and the cylinder head pot of the crankcase is a brass seat ring. This seat ring is designed to prevent the passage of exhaust gasses into the crankcase, prevent oil from the cylinder head area from passing into the exhaust, and provide a wear surface between the underside of cylinder head flange and the crankcase head pot. Wear in this area can be kept to a minimum by following proper procedures for crab nut torquing during tightness checks and power assembly changeout.

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ITS Locomotive Training Series - Student Text

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3 3

3 3

The Plate Crab Torque Procedure is as follows:

3 On each bank of cylinders : 1.

2. 3. 4.

5. 6.

3

Torque all outboard crab nuts to 500 ft lbs. Torque all inboard crab nuts to 500 ft lbs. Torque all outboard crab nuts to 1000 ft lbs. Torque all inboard crab nuts to 1000 ft lbs. Torque all outboard crab nuts to 2400 ft lbs. Torque all inboard crab nuts to 2400 ft lbs.

3 3 3 3

Crab bolts have special rolled type threads, and can not be repaired with a die nut. Damaged crab bolt threads'should be repaired using a thread file or if not salvageable, the bolt should be replaced.

3 3

3 Crab Bolt Changeout Procedure

3

When a crab bolt breaks, the engine should shut down due to crankcase pressure caused by airbox air. All adjacent crab bolts must be changed due to the stress loading caused by the broken bolt.

4

Broken Crab Bolt

3 3

3 3

3 REPLACE THESE BOLTS

3 k Off to Half Toque

Figure 3.35 Crab Bolt Changeout Procedure

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3 Power Assembly Changeout Procedure

3

When changing a power assembly, the crab nuts on the cylinders adjacent to assembly being changed must be backed off to 1/2 torque (approximately 1000 ft Ibs). The crab nut retorque procedure after changing a power assembly is as follows:

3 3

1.

2. 3. 4. 5.

6.

Torque the 2 removed outboard crab nuts to 500 ft lbs. Torque the 2 removed inboard crab nuts to 500 ft lbs. Torque the 2 removed outboard crab nuts to 1000 ft lbs. Torque the 2 removed inboard crab nuts to 1000 ft lbs. Torque the 2 backed off and the 2 removed outboard crab nuts to 2400 ft lbs. Torque the 2 backed off and the 2 removed inboard crab nuts to 2400 ft lbs.

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Electro-MotiveModel 567,645 84 710 Series Diesel Engines

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Back Off to 1000 FT LBS

Back Offto 1000 F l LBS

Figure 3.36 Power Assembly Changeout Procedure

Head Seat Ring Three types of head seat ring have been used, bronze, aluminum bronze, and aluminum bronze with integral viton seal. The viton seal was added to reduce "souping" (engine oil passing through the head seat ring area into the exhaust runner and then blown out with the exhaust gases). An additional benefit of the viton seal was a reduction in wear between the head pot and seat ring because of the reduction of oil flow with gritty material through this area. Worn head seats can be repaired by machining and using a thicker (oversize) head seat ring or by building up the surface with weld and re-machining to the original dimension (special machinary needed).

CYLINDER HEAD F!ANQE

HEAD SEAT RlNQ WlTH SEAL

CWNDER HEAD RETAINER

Figure 3.37 lntegral Seal Head Seat Ring Application

Camshafts The typical 16 cylinder engine, shown here as an example, is equipped with two sectional camshafts, one per engine bank (Figure 3.38). The camshafts operate the fuel injectors (one pet cylinder), and the exhaust valves @bur per cylinder operated by two rocker arms and two valve bridges).

ITS Locomotive Training Series -Student Text

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3

3 3 At each cylinder location are three cam lobes, one injector and two exhaust. The camshafts are a sectional design, with each section spanning four cylinders on this engine (and on 8 cylinder engines). Each camshaft segment on a 20 cylinder engine spans 5 cylinders and on a 12 cylinder engine, 3 cylinders. The sections are flanged, with dowel bolts to allow for individual section removal.

3

3 3

Stub shafts at the rear of the camshafts connect to the rear gear train, and at the front connect to counterweights which dampen torsional forces.

3

The camshafts are supported by two bearings at each cylinder location to ensure minimal flexing of the shaft. These bearings are lubricated by oil passages drilled in the camshaft.

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3

Oil enters the shaft by way of the rear bearing block (or oiler block) and then travels up the interior of the shaft to each bearing.Each cam bearing is a split design with upper and lower shells retained by a bearing cap. The right hand bearing cap at each cylinder has a drilled passage, allowing oil from the bearing to pass through the jumper line to the rocker arm assembly.

3

3 3

Camshafts on engines before 645EB were cast 5046 steel. Camshafts on 645EB to 645FB are forged 1080steel or "hard" cams. Forged 1080 steel cams can be used as an upgrade on any 567 or 645 application, but 5046 steel cannot be used with the 1/2" plunger fuel injectors on 645EB and later engines.

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3 3

LEFT-HAND ROTATION ENGINE Long Segment Long Segment BmA

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3

BmA

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Left Bank Stubshaft

Spacer

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Right Bank

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Stubshaft

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Long Segment

Long Segment

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RIGHT-HAND ROTATION ENGINE Long Segment Long Segment

Left Bank

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LOW&ant Injector Cam

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LONG SEGMENT

-Exhaust Valve Cams

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Journal

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Figure 3.38 Typical Camshafthangement

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3-28

Electro-Motive Model 567.645 & 710 Series Diesel Engines

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Duracam New for the 710G3B engi.ne is the DURACAM with a exhaust lobe profile slightly different than previous 710 camshafts. The ramp angle of the new lobe profile allows for more graceful unseating of the exhaust valves by slowing the travel of the valve at the begining of its cycle. The new profile incorporates an acceleration ramp which provides more rapid valve movement from unseated to full open position. A deceleration ramp on the closing side allows the valves to stay open longer, close more rapidly, then slow before seating. DURACAM is available for 645 and 710 applications. DURACAM has undergone a design change for the 16-710G3C, with the shaft being made thicker in all non-lobe areas to eliminate vibration at the higher maximum RPM. This cam is being used on all new 8 and 16 cylinder 710 engines.

TTS Locomotive Training Series - Student Text

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Rear Gear Train

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The rear gear train provides power to drive the camshafts and, depending on engine model, the blowers/or turbocharger.

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3

The gear train is located on the rear, or flywheel end of the engine and consists of:

3

crankshaft gear #I (or lower) idler gear #2 (or upper) idler gear left and right camshaft gem turbo drive gear or; blower drive gears

3

The camshafts are driven at a 1:l ratio, they make one revolution every revolution of the crankshaft.

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3 3 3 3 Figure 3.39 Rear Gear Train (Turbo)

Rotation

3 3

Camshaft Drive

The camshafts are driven off the #2 idler gear. The left bank camshaft gear meshes with the #2 idler and then drives the right bank camshaft. The camshafts therefore rotate in opposite directions inboard towards each other. The #2 idler has an extra row of teeth that are used to drive the turbocharger.

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Figure 3.40 Rear Gear Train (Blower Type)

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f Electro-Motive i Model 567,645 & 710 Series Diesel Engines 0

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ldler Stubshaft Bracket

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The idler stub shaft bracket provides a mounting fixture for the idler gears and is bolted to the rear of the engine block. This bracket also contains oil passages to direct lubricating oil from the oil gallery in the engine block to the rear gear train, camshafts and turbo if equipped.

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Figure 3.41 ldler Stubshaft Bracket Application

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Auxiliary Drive

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Also located on the rear of the engine block is an optional auxiliary drive gear, (used to drive an auxiliary generator in rail applications). O n blower engines, the auxiliary drive gear meshes with the top center of the number 2 idler gear, with the drive flange located between the blowers.

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O n turbo engines the auxiliary drive assembly is mounted on the turbocharger housing and is driven by the outboard side of the right bank camshaft gear.

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Figure 3.42 Awdiary Drive (Turbo)

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ITS Locomotive Training Series Student Text

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3 3 Figure 3.43 Clutch Drive Gear Assembly

Figure 3.44 Spring Drive Gear Assembly

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Drive Gear

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On turbocharged engines there are two types of number 2 idler gear / turbo drive gear assemblies, the spring drive gear, and the clutch drive gear.

3

Clutch / Spring

The clutch drive gear, introduced on the 710 engine is similar to design and function to the internal turbo clutch, but is larger and much stronger. Another advantage to this design is that this clutch can be removed and inspected or rebuilt without disassembling the turbocharger.

3 3 3 3

The spring drive gear is used on engines with internal clutch turbochargers to absorb torsional vibration and cushion the gear train from the shock loads of the turbo clutch engaging and disengaging. On right hand rotation applications, the #2 idler gear drives the right bank camshaft gear, which keeps the camshaft gear rotation inboard towards each other. Right hand rotation engine turbochargers have an extra idler gear added so the turbo rotates the same direction as a left hand rotation engine turbocharger.

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3 3 /3

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Electro-MotiveModel 567,645 & 710 Series Dlesel Engines

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Governor

Accessory Drive The accessory drive gear train (Figure 3.45) is located at the front, or governor end of the engine and is used to power the oil pumps, water pumps, and governor.

The components are: accessory drive gear scavenging oil pump gear main lube and piston cooling pump gear governor drive gear water pump gears

Figure 3.45 Accessory Drive Gear Train

The accessory drive gear is a coil spring dampened gear assembly that provides a smooth flow of power from the crankshaft to the accessory gears.

Figure 3.46 Accessory Drive Gear

The scavenging pump drive gear is powered directly off this gear, as is the main

lube and piston cooling pump drive gear.

The governor drive gear is mounted on a stub shaft assembly above the main lube drive gear. As the main lube pump drive gear is rotated by the accessory drive gear, the governor drive gear turns, powering the governor and the left and right water pump drive gears.

The governor angle drive is splined onto the center of the governor drive gear. The gear train is enclosed by the accessory drive housing which provides mounting fixtures for the pumps and governor. ITS LocomotiveTraining Series - Student Text

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645 - 710 ENGINE COMPARISON 710 Piston The increase in displacement from 645 to 710 comes from the 1 inch (25mm or 2.5cm) increase in stroke length. The length of the 710 piston is also increased 1 inch in order to keep the air inlet ports in the liner covered at the top of the piston stroke to maintain the seal bteween the airbox and oil pan. The piston pin centerline location was lowered 1 inch in relation to the piston crown to maintain interchangeability of the piston pin, carrier, and connecting rods with the 645. This also improves piston dynamics and reduces 1’iner wear.

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Figure 3.47 Piston Dimensional lncrease

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Cylinder Liner

I The 710 cylinder liner is structurally identical to the 645 liner with the exception of being 2 inches (50.8mrn or 5.08cm) longer. One inch is required from the bottom of the air inlet ports to the top of the liner to accommodate the one inch increase in stroke.

710

The additional inch from the bottom of the air inlet port to the bottom of the liner is required to contain the longer piston.

Figure 3.48 Cylinder Liner Dimensional lncreases

m 3-34

Electro-Motive Model 567, 645 & 710 Series Diesel Engines

Cylinder Head Two factors account for the 30°F (-1OC) decrease in cylinder head operating temperatures of the 710 engine despite the higher peak firing pressure and temperature. The first is the increased air flow of the Model G turbocharger, which reduces the thermal load. The second is a new casting process that results in a reduction in the range of firedeck thickness. This allows a reduction in firedeck thickness to improve heat transfer.

Crankshaft and Main Bearing The 710 crankshaft has a main bearing journal diameter that is 1 inch larger than This allows the use the 645 but retains the same crankpin diameter 6.5 inches (16.5cm). of the 645 fork and blade rod assembly with the 0.5 inch (1.3cm)longer throw of the 710 crankshaft. The main bearings of the 710 engine are also 1 inch larger diameter to match the crankshaft,but are the same width and use the same torque specifications as 645 engines.

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SOCction A-A

0.50"

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I Figure 3.49 Crankshaft Comparison

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ITS LocomotiveTraining Series Student Text

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Camshaft and Rocker Arm Assembly

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The camshaft and rocker arm assembly of the 710 engine has been redesigned to accomodate the increased forces caused by the larger 0.5625 inch (1.4cm)injector plunger. Changes include strengthened rocker arms with larger diameter cam followers, cam lobe base circle increased by 0.75 inch (1.9crn),increased distance between camshaft and rocker arm, and a new injector. The only part shared with 645 engines are the rocker arm shaft bushings.

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Figure 3.50 Rocker Ann Assembly

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Electro-Motive Model 567,645 & 710 'Sries Diesel Engines

13

CHAPTER Fuel System

introduction The fuel system is responsible for supplying fuel to the diesel engine in the correct quantity and at the right time according to engine requirements. To do this, the fuel must be supplied, filtered, pressurized, metered, and injected. The system may be divided into two parts, supply side and the delivery side.

The supply side of the fuel system consists of the fuel tank, fuel pump, filters, and piping.

T h e Fuel Pump is protected by the suction strainer.

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Fuel is drawn from the tank through a suction strainer by the fuel pump. The strainer has a screen type element that removes-large debris from the fuel. This protects the pump against damage from foreign material. The suction strainer should be removed and cleaned or replaced when required at intervals specified in the appropriate Scheduled Maintenance Program - Maintenance Instruction. It is also recommended that the condensate be drained from the fuel tank at the scheduled interval or more frequently during periods of high humidity. Figure 4.1 Fuel Suction Strainer

ITS Locomotive Training Series - Student Text

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The gear type fuel pump may be driven by a DC or AC motor. The pump is designed to ensure adequate fuel supply at all engine speeds. Note that some stationary and marine installations may use a mechanically driven fuel pump mounted on the end of the scavenging pump.

Suction

D ischarae

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Body

Rotor O n some systems, the fuel passes through a temperature sensitive flow valve (typically Figure 4.2 Fuel Pump Cross Section called an M O T valve) before flowing to the primary fuel filters. -The M O T valve diverts the fuel through the fuel heat exchanger as required to maintain a constant fuel temperature of 100 degrees F. (37.74 Co)

From the heat exchanger, the fuel passes through the primary fuel filters before going to the diesel engine. The primary fuel filters typically consist of one or two 1 3 micron filter elements located in canister type housings. On newer systems, these filters are equipped with a bypass valve. Should the filters become plugged, the back-pressure to the fuel pump will increase. When the pressure difference across the bypass valve reaches 30 psi (206.85 kPa), the valve will open diverting fuel around the filters. In most cases the valve is equipped with a gauge to indicate filter condition.

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The'secondary, or engine mounted fuel filters, are 2 micron elements located on the front left corner of the diesel engine. As with the primary filter(s), these filters are equipped with a bypass valve. The bypass valve is located under a sight glass to provide a visual indication of plugged filters. Should the filters begin to plug, the back-pressure to the primary filters will increase. When the pressure reaches 60 psi, the valve will open to divert the fuel flow. In this case however, the fuel is returned directly to the fuel tank instead of passing around the filters.

As filter condition worsens, more and more fuel is directed back to the tank.

Figure 4.4 Engine mounted fuel filters and b e 1 sight glasses 1.

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2.

3.

RETURN FUEL SIGHTGLASS BYPASS SIGHT GLASS SPIN ON FUEL FILTERS

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As the fuel is diverted, engine performance decreases also. If the filters become severely plugged, the engine will die of fuel starvation. To avoid this kind of problem, primary and secondary fuel filters should be changed at regular intervals. From the secondary filters, the fuel is delivered to the injectors by the fuel rails (supply fuel manifolds) located inside the top deck area of the engine. Jumper lines connect each injector to the fuel rail and fuel circulates freely through each injector before exiting out another jumper line to the fuel return rail (return fuel manifold). The injectors use what fuel is necessary for engine demands, the rest serves to cool and lubricate the injectors. The fuel returning from the injectors passes through a return fuel check valve and return fuel sight glass before returning to the fuel tank. The return fuel check holds a certain amount of pressure in the engine to ensure proper injector operation. Depending on engine requirements, this check valve may be set for 5 , 7 , or 10 psi.(34.4,48.3, or 69 kPa). The return fuel sight glass provides a visual indication of fuel system condition. If the system is operating properly, the sight glass will be full of clean clear fuel. Air bubbles may indicate filter problems, suction leaks, or faulty injectors.

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ITS Locomotive Training Series -Student Text

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19 Figure 4.5 Fuel System, Pictorial Diagram

3

3 Delivery

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The delivery side of the system consists of the fuel injectors, the layshaft mechanism, and the control device or governor.

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The measuring and timing of the fuel must be carried out simultaneously, or in the proper sequence and in the simplest manner by every fuelinjection system regardless of type.

The fuel must first be delivered to the injection mechanism. The pressure of the fie1 delivered by the injection mechanism must be suffcicientto overcome the pressure of compression. The rate of fuel injection must be controlled. The fuel must be broken up or atomized into fine parh'cles. The fuel must be properly distibuted in the combustion chamber.

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ElectrMotie Model 567,645 & 710 Series Diesel Engines

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Unit lnjector System The unit injector system, shown in Figures 4.5a and 4.5b, is a development of the individual pump injection system. Instead of an individual pump connected to an injection nozzle by a high-pressure fuel line, the pump and nozzle are combined in a single unit injector which performs all the injection functions. Eliminating the high pressure fuel piping permits extremely high injection pressures - up to 20,000 or even 30,000 psi. (1 37,900 kPa or even 206,850 kPa) Each cvlinder head carries a unit injector, which is actuated by a rocker arm from the camshaft. Within the unit are a pump plunger, which raises the fuel pressure, meters the charge and times the injection, a delivery valve and a nozzle tip to give the desired spray pattern.

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Figure 4.5a Fuel lnjector

Figure 4.5b Fuel lnjector - Cross Section

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ITS Locomotive Training Series - Student Text

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Injector Operation ,.

The unit injector, on being depressed by the rocker arm, takes fuel from the supply system and meters, times, pressurizes, and atomizes the fuel into the engine cylinder. Figures 4.6 illustrates the operation of the injector at approximately a half load position.

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TOP OF STROKE

BYPASS POINT

INJECTION STARTS

BOTH PORTS OPEN TO ADMIT FUEL

FUEL BELOW PLUNGER BOTH PORTS CLOSE ESCAPES THROUGH FORCING FUEL INTO UPPER WRT. NO CYLINDER EFFECTIVESTROKE

INJECTION ENDS

BOTOM OF STROKE

LOWER PORT STARTS TO OPEN ALLOWING FUEL BELOW PLUNGER TO ESCAPE

LOWER PORT FULLY OPEN. NO EFFECTIVE STROKE

ONE COMPLETE DOWN STROKE OF PLUNGER AT "HALF LOAD" POSITION

Figure 4.6 Znjector Fuel Control

In figure 4.6, the injector plunger is at the top of its stroke. Note that both the upper and lower ports are open and fuel is allowed to enter the chamber below the plunger. The plunger has a machined recess called a helix. Fuel flows from the upper port into the helix, and though a drilled pwssage in the plunger.

As the plunger begins to move down by the rocker arm, the lower port is blocked by the plunger. Fuel is allowed to escape back through the drilled passage, helix, and upper port.

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Next, the plunger has moved down far enough to close both ports. At this point, as the fuel is trapped below the plunger, fslrther downward motion of the plunger generates higher fuel pressure. This pressure lifts the needle valve and injection begins.

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As the plunger continues downwards, the lower port starts to open, allowing fuel to move up through the drilled passage, escaping through the lower port, ending injection.

3 3

The plunger travel continues until the bottDm of its stroke, however, the lower port is fully open and no injection can take place.

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ElecMotive Model 567, 645 & 710 Series Diesel Engines

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645

710 -I

PRESSURES.

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NOTE : EXHAUST VALVES OPEN BEFORE & CLOSE AFTER THE OPENINWCLOSING OF THE CYLINDER AIR PORTS TO MAXIMIZE CYLINDER CHARGING

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Maximum Fuel

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42 Exhaust Valves

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Exhaust Valves

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Exhaust Valves Ports Open

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Figure 4.7 Timing Diagram (645 Turbo)

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ITS Locomotive Training Series - Student Text

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Ls 3 3 Injection Control

3

The quantity of fuel injected is controlled by rotating the plunger with the rack. The amount of fuel injected increases as the rack moves in. As the plunger rotates, the change in the helix in relation to the ports changes the effective length of the stroke. Figure 4.7 illustrates the effective injection stroke with the rack in different positions.

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3 3 Effective Stroke

1

Lower Port

NO INJECTION RACK CLEAR OUT

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NO INJECTION RACK ,088"IN

IDLE

HALF LOAD

FULL LOAD

ONE COMPLETE DOWN STROKE OF PLUNGER AT "HALF LOAD" POSITION

3 3 3 3 3 3 tp

3

Figure 4.8 Plunger Fuel Control

44 Position of the rack is set by the Woodward governor in response to engine speed requests. The governor compares actual engine speed with desired speed and adjusts the fuel rate accordingly.

3

GM has made a significant contribution to the reduction of exhaust smoke and gaseous emissions with the introduction of a new LOW SMOKE fuel injector. The key to the LOW SMOKE injector is the new design LOW SAC spray tip. The spray tip features a 53% reduction in the fuel sac below the needle valve seat. Significantly less fuel remains below the needle valve after it has seated, thereby reducing the potential afterdribble of fuel which causes smoke and undesirable emissions

3

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EMDEC Electronic Injection Control EMDEC is an advanced electronically controlled fuel delivery system which can be original equipment on a locomotive, or retrofit to appropriate engine models. Fuel flow through this system will not be radically different from past applications but injection control is based on an electronic system versus the older mechanical system. This section provides an overview of system operation. For further information, consult the EMDEC Electronic Injection Manual.

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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FUEL FLOW AND SYSTEM COMPONENTS As on older systems, an electrically driven pump pulls fuel from the tank through a suction strainer. The pump is now driven by an AC electric motor instead of the DC motor found on older systems. The wiring and piping connections remain the same. A motor mounted inverter handles the conversion from 74VDC to AC required by the motor. The pump has a capacity of 6.5 gallons (24.6 L) per minute and is identical to the turbo lube pump.

Figure 4.9 Typical AC motor driven pump

G From the pump, the fuel is then forced on to a fuel pre-heater (where equipped). The heater is thermostatically controlled to maintain fuel temperature at about 100°F (37.74"C). Maintaining a constant fuel temperature aids in injection control and helps to ensure consistent engine performance.

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Figure 4.10 Suction struiner

From the pre-heater, fuel is passed through a primary fuel filter assembly equipped with a 30 psi (206.85kPa) bypass. Two 13 micron elements in parallel compose the assembly and have been increased in size from older systems, with each element measuring 30" (76.2cm) long and 10" (25.4 cm) in diameter.

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These are the same elements as used in lube oil filtration. The filters are located on the left side of the locomotive above the lube oil filters.

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Figure 4.1 1 Primary filter assembly ITS Locomotive Training Series -Student Text

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Figure 4.12 Engine mounted fuel equipment

From the primary filter, fuel passes to secondary filters before continuing to the injectors. The secondary filters are 5 micron spin on units located at the front of the engine, however they have been increased in size to handle the additional fuel flow required for this engine. Note also that the sight glasses have been eliminated on this engine. The secondaries are equipped with a bypass valve that will route the fuel to the tank if the filters become plugged. Bypass pressure has been increased from 60 psi (413.7 kPa) on older systems to 120 psi (827.4 kPa) with the electronic injection.

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The fuel manifolds used are noticeably larger than past applications and jumpers between the manifold and injectors are now made of flexible braided hose rather than the traditional rigid copper tubing. Only a small portion of the fuel that is circulated through the injectors is used for injection, the remainder lubricates and cools the injectors. This excess fuel is directed through the return fuel manifold to a check valve. This valve retains 40 psi (275.8 kPa) back pressure in the manifold and injectors to ensure proper injector filling and aid in starting. The control units for the injection system (2 for 16 cylinder, 3 for 20 cylinder), are mounted on a cold plate on the front of the engine. O n its way back to the tank, return fuel cycles through this plate and cools the injection modules.

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L) Electro-MotiveModel 567, 645 & 710 Series Diesel Engines

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ELECTRONIC FUEL CONTROL

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The electronic fuel control system regulates both timing and metering of fuel to optimize emissions and fuel consumption for various engine loads at any set ambient conditions. In other words, an engine required to produce 4300 horsepower with a fuel temperature of 100°F (37.74"C) and air inlet pressure of 21 psi (144.8 kPa) may inject a different amount of fuel at a different timing with respect to Top Dead Center when compared to the same engine producing 5000 horsepower with a fuel temperature of 60°F (15.54"C) and an air inlet pressure of 27 psi (186.165kPa).

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The presence of electronic fuel control provides variable fuel delivery as well as the first real computer aided engine troubleshooting tool available on a GM locomotive. Because the computers which control operation of the injectors interface with the EM2000 locomotive control system, shop maintenance personnel are able to monitor the following:

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many injector functions such as metering, timing, response time to ECM commands (Engine Control Modules) fuel temperature fuel pressure before and after primary filtration engine & aftercooler coolant temperatures engine coolant pressures on left & right banks and discharge to radiator lube oil temperature lube oil pressure from turbo cylinder air inlet pressure engine's capability to handle given loads (displayed as LR%MAX) turbocharger inlet air temperature charge air (cylinder inlet ports) temperature

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At first glance, the most significant change to the engine is the lack of Woodward governor, layshaft, load regulator and overspeed mechanism. These functions are now handled electronically by the ECM's (Engine Control Modules).

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Figure 4.14 EZecfronic Fuel Injectors

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Electro-MotiveModel 567, 645 & 710 Series Diesel Engines

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The injection system uses two magnetic pickups mounted at the rear coupling disk to provide basic timing information. The pickups read the position of timing indicator plates mounted on the coupling disk. As the coupling disk rotates, these plates are moved past the pickups to generate an electronic signal to the ECM's. The first pickup, Synchronous Reference Sensor or SRS, generates one signal per revolution of the engine at four IR9/5RS / degrees before top dead center of the TARQET -._ _.ASSEMBLY number one cylinder. This signal CAMSHAFT DRIVE eND synchronizes the ECMs with respect to engine speed and Crankshaft position. The second pickup, Timing Figure 4.17 Timing indicator pickups Reference Sensor, or TRS reads the metal spokes of the timing plates located on the coupling disc. There are 36 equally spaced spokes, so each pulse from the TRS indicates the crankshaft has moved 10 degrees. Engine speed is determined by the ECMs from the elapsed time between TRS pulses. The exact timing and duration of injection is controlled and adjusted by the ECM's according to load, performance, and ambient conditions. Timing of injection therefore is no longer adjusted manually in maintenance facilities with tools, instead it has become a software item controlled and varied according to ambient conditions by the engine control computer. TRSTARQES

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Figure 4.18 depicts fuel flow in the electronic injector with the plunger at the top of the stroke and the poppet valve open. Note that clean, cool fuel continually circulates through the upper portion of the injector as supplied by the fuel pump. The openposition of the electrically controlled poppet valve allows the fuel to enter the pump chamber and fill it. This flow of fuel ensures a reliable supply of fuel to keep the injector filled and as on the older systems, serves to cool and lubricate the injector.

Figure 4.18 Fuel flow during cooling (no injection) 4-14

Electro-Motive Model 567,645 & 710 Series Diesel Engines

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Figure 4.19 shows fuel flow in the injector with the plunger moving downwards. This would take place as the piston is approaching top dead center. As the plunger moves downward with the poppet valve open, no pressure is created, The fuel displaced by the plunger travels through the open poppet valve into the lower fuel chamber. At the exact point that injection is to begin (as determined by the ECM), the electrically controlled poppet valve closes and fuel is trapped in the injector below the plunger. As plunger motion continues, the trapped fuel is pressurized by the plunger and unseats the needle valve at the injector tip to allow injection. The longer the electrically controlled poppet valve remains energized during plunger motion, the more fuel is delivered (metering). When injection is to stop, the poppet valve opens and high pressure fuel from the pump chamber is allowed to escape through the valve to the return fuel line. When the pressure at the injector tip drops below 2OOOpsi (13790 kPa), the needle valve closes to stop injection. The point at which injection begins and ends (timing) is completely controlled by the ECM energizing and de-energizing the poppet valve.

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Figure 4.19 Fuel flow during injection

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TTS Locomotive Training Series Student Text

4-15

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3 FUEL SYSTEM TROUBLESHOOTING

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Before attempting to determine the cause of a fuel system problem, verify that there is fuel in the fuel tank. Occasionally, a stuck or broken fuel level gauge will show fuel in the tank when it is empty. Some of the common fuel system problems are covered here along with suggested solutions.

Low or No Fuel Pressure Ensure that the fuel pump breaker is in the on position and is not tripping out. With the start switch in prime, verify that the pump and motor are both turning. Observe the 6Opsi (413.7 kPa) bypass sight glass, if fuel is present check to make sure the relief valve is not stuck open. Remove and clean the suction strainer and change all fuel filters. Visually examine all piping (internal and external) for leakage, restriction, and partially closed valves.

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Internal Fuel Leaks Fuel leaking inside of the engine can be detected by observing a high or rising engine lube oil level, or by lube oil analysis. Large enough quantities of fuel will dilute the lube oil and reduce its lubricating ability. Inspect the top deck area for leakage from injectors, top deck fuel manifolds, and injector jumper lines, paying particular attention to jumper line seats on the injectors and the fuel manifold. Do not stop looking after one leak is found, but continue until all cylinders have been checked.

If no leaks are found, it is possible that the injectors are leaking internally. Worn out or physically damaged injectors can leak fuel into the cylinders, past the rings, and into the lube oil.

To check for leaking injectors, perform a ''one revolution" inspection of the engine, checking for fuel, or fuel "washed" appearance in each piston crown. Any injectors showing signs of leakage should be replaced with a new or qualified unit.

Bubbles in Return Fuel Sight Glass The return fuel sight glass (the glass closest to the engine block) should normally be full of fuel and clear of bubbles when the engine is running. If bubbles are observed in the return sight glass, shut the engine down, hold the engine start switch in the fuel prime position, and observe the sight glass. If the bubbles stop, the probable cause of the bubbles was an injector with tip leakage, which can be located using the above procedure.

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Electrc-Motive Model 567,645 & 710 Series Diesel Engines

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Fuel in Bypass Sight Glass

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Normally the bypass sight glass (the glass farther from the engine block) is empty. Fuel in this sight glass indicates that the bypass relief valve is open as a result of the back pressure caused by clogged engine mounted fuel filters. If fuel is still present after changing the fuel filters, the relief valve should be inspected for a broken spring or stuck plunger.

Intermittent Fuel Starvation Foreign material in the fuel tank that is too large to go through the fuel suction line can block the intake and cause fuel starvation. When the engine is shut down, or expires from lack of fuel, the material may be released when the suction from the fuel pump stops. When the engine is started again, it will run properly, until the material is picked up again by the fuel pump suction. The fuel tank should be drained to remove the objects, and if the problem continues, the tank will have to be opened up to clean it out.

Locating a Misfiring Injector Individual injectors can be checked for proper operation while installed in the engine by two methods, the injector pressure test and the "clunk" test. "Clunk" test With the engine at idle speed, remove the spring clip and clevis pin from each injector control lever one cylinder at a time. Slowly open the rack by pulling outward on the injector control lever, and then return it to idle position. If the injector is operating properly, the cylinder will fire with a pronounced ''clunk" with the rack advanced.

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Injector Pressure Test (Pop Test): Special tool #4002 1839 is required to perform this test.

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that the engine fuel lines are fully charged, bar the engine over until the injector cam roller for the cylinder being tested is below the exhaust cam rollers (check with straight edge).

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ITS Locomotive Training Series - Student Text

4-17

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- Apply the test tool to the injector rocker arm with the lower end of the times undei the rocker arm shaft and the top of the tool covering the rocker arm adjusting screw lock nut.

- Remove the spring clip and clevis pin from the injector control lever and place the injector rack in the full fuel position.

- Insert a 1/2 inch drive torque wrench in the test tool, and apply and hold 80ft-bs (107Nm) of torque for a minimum of five seconds. If the torque remains constant without moving the wrench, the injector is acceptable. If the wrench must be moved to maintain the torque or the indication drops off, the injector is leaking and must be replaced.

4-18

Electro-fvlotive Model 567, 645 & 710 Series Diesel Engines

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SYSTEM MAINTENANCE (EMDEC)

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Maintenance of the fuel system normally consists of a few minor tasks performed as part of a scheduled maintenance program. These tasks do not differ significantly from those performed on a conventional mechanical fuel injection system. Always consult your company's maintenance instructions for specific inspection items and frequency.

SCHEDULED MAINTENANCE Daily or Trip The fuel level should be checked frequently to ensure that the engine has an adequate supply for operation. Running the engine frequently with a low fuel level can lead to early filter failure due to the buildup of condensation and other contaminants in the tank. It can also can lead to early injector failure since the injectors rely on the fuel for cooling. A low fuel level will allow temperatures to rise dramatically. Visually check the gauge on the tank to ensure that the fuel level is adequate before dispatching the unit. Also check the primary fuel filter bypass gauge to ensure the filters are in the serviceable zone. Closely examine all piping and components for damage or leakage,

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90 Day Inspection

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At 90 days, the primary fuel filters should be renewed. With the engine shut down, open the fuel filter access doors. Remove the filter elements, thoroughly clean the tanks, and renew the 2 paper elements. Apply new seals and secure the access doors.

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The secondary (engine mount or twin spin) filters are also renewed on the 90 day inspection. Pre-fill both elements with clean fuel before applying to the engine, This procedure has not been altered from previous design engines.

180 Day Inspection On 180 day inspection, remove and inspect the suction strainer for debris and contaminants. Clean or replace the element, renewing the canister seal.

3 Year Inspection On the 3 year inspection, remove all fuel injectors and replace with qualified replacements.

6 Year Inspection The 6 year inspection is the major inspection interval. Remove and recondition fuel pump and motor. Renew the drive spider between the motor and pump. Check pump operation before dispatching locomotive.

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Ifs Locomotive Training Series Student Text

4-19

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Remove all EMDEC control equipment and replace with qualified components. Closely inspect all wiring harnesses, connectors and sensors for defects. Examine the engine timing and speed pickups. Reset air gap on all pickups. Qualify the primary fuel filter bypass valve and gauge, replace if required.

Fuel System Troubleshooting (EMDEC) Although troubleshooting procedures on the EMDEC equipped engines are very different to those used on mechanical injection models, as a rule, less problems can be expected with the new system. Troubleshooting the system is easier with the diagnostic capabilities built into the EMDEC system and the EM2000. Conditions in the fuel system can be monitored by the use of a laptop computer connected to EMDEC through an RS-232 communications port in the cab of the locomotive. Fuel temperature and pressure, injector response and engine timing are a few of the items that can now be monitored while the engine is running. Problems with the fuel system generally can be classed as: (1) a loss of fuel pressure to the injectors (supply problem); (2) defective injectors; or ( 3 ) control problems (EMDEC electronics).

Low Fuel Pressure (EMDEC) Fuel pressure and temperature is constantly monitored by the EMDEC control unit through the use of a pressure sensor and a temperature probe both located at the fuel distribution block on the front of the engine. This information is used by EMDEC for fuel delivery calculations. Should either condition move outside of normal operating ranges, EMDEC will cause an engine shutdown and display a fault condition. When an engine is reported as having low fuel pressure, the following steps should be taken: 0

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check condition of the filters by means of the bypass gauge located by the primary fuel filters.

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change all fuel filters and clean or replace the suction strainer.

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visually examine all piping and hoses for leakage or restrictions.

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check the level of fuel in the tank.

determine whether the problem is actually low pressure, or an incorrect reading by the pressure transducer. Fit a mechanical gauge to the pressure sensor location using a "Tee" fitting. When the engine is operating, the gauge and the reading indicated by the sensor should be within a few pounds of each other. If not, replace the sensor with a qualified unit. If the mechanical gauge indicates a true low pressure situation, the procedures for qualifying the system remain the same as in the past. Electrdvlotive Model 567, 645 & 710 Series Diesel Engines

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disconnect the fuel return line at the distribution block and attach a length of clear hose that will allow fuel return to be observed. Check the return fuel for air bubbles that could indicate a suction leak. Also observe the quantity of fuel flowing with the engine shut down and the pump running. The flow should be between 4 and 5 gallons (15.14 and 19 L.) per minute in order to run the engine at full power.

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Refer to the Engine Troubleshooting Section of the manual, or the separate Diesel Engine Troubleshooting Guide for further checks.

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Faulty Injectors (EMDEC)

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Normally the injectors are controlled by EMDEC and deliver very precise amounts of fuel. If the injector is faulty, there will be a noticeable change in engine performance. Injectors can fail in several different manners, but all will impact cylinder power levels. Some of the more common failure modes are: 0

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failure of the energizing coil (open or shorted) will cause a complete failure of injection as the poppet valve will not seat to build pressure for injection. a faulty poppet valve (stuck or leaking) will not allow the pressure to build for injection, or if stuck closed, will not allow the injector to fill below the plunger. a leaking or badly worn plungerharrel assembly will lead to low injection pressures and poor performance.

if the injector tip, spring, needle, or check are damaged, the injector Performance will be severely affected. Problems in this area are identical to the problems found on the older mechanical injectors.

Injector problems can be isolated and identified by two methods. Using the laptop computer, all injector response data can be monitored and a cylinder cutout test can be performed. Cut out the injectors one at a time with the computer and note engine response. If a good injector is cut out, there will be a slight change in engine sounds and the fuel delivery rate will be adjusted on all other injectors to compensate. If a faulty injector is cut out, there will be no change to engine sounds, speed, or injector delivery rates. This test is similar to performing the ttclunktttest on older systems.

Injection Control Problems (EMDEC) When troubleshooting a control problem it must be determined: (1) if there is a true fault; (2) is the pKQb)erF;Irelated to a software problem; or (3) is the problem due to a failure of an EMDEC component or associated wiring or other hardware. It helps to follow a set routine and logical order of checks when trying to isolate a problem. Verify all simple conditions first and use the control computer and laptop to help diagnose the problem . 0

check the fault archive in the EMDEC control unit to verify the system failure. The computer may provide an indication of the cause of the failure such as the communication between control units, communication fiom the control unit to the injectors, or the failure of a control unit itself.

ITS Locomotive Training Series -Student Text

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check the level of fuel in the tank. check condition of the filters by means of the bypass gauge located by the primary fuel filters.

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change all fuel filters and clean or replace the suction strainer.

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visually examine all piping and hoses for leakage or restrictions.

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determine whether the problem is actually low pressure, or an incorrect reading by the pressure transducer. Fit a mechanical gauge to the pressure sensor location using a "Tee" fitting. When the engine is operating, the gauge and the reading indicated by the sensor should be within a few pounds of each other. If not, replace the sensor with a qualified unit. If the mechanical gauge indicates a true low pressure situation, the procedures for qualifying the system remain the same as in the past.

Engine Stafiing Procedure

Before attempting to start an engine that is new, remanufactured, or has been shut down for more than 48 hours, engine prelube is to be petformed. This procedure is described in Chapter 6 of this text.

Check levels of engine oil, governor oil, compressor oil, and engine coolant. Open cylinder test valves and bar engine over at least one revolution. While closing test valves, watch for discharge of fuel, engine oil, or engine coolant. If any of these are found, determine the cause and make the required repairs. Remove the starting fuse. Check that all fuses are present and in good condition, and of the proper rating. Verdy that the main battery switch is closed, and that the ground relay switch is clssed. Place the local control and the control circuit breakers in the ON position. Place the control and fuel pump switch in the ON position. Place generator field and engine run switches in the OFF position. Turn isolation switch to the START position.

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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At the equipment rack in the engineroom, place the Fuel PrimeEngine Start switch in the PRIME position until fuel flows in the return fuel sight glass clear and free of bubbles. Check that the starting fuse is in good condition and proper rating then install it. -P 6

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CAUTION: Do not crank the engine for more than 20 seconds or "inch" the engine with the starter. After cranking allow a minimum of two minutes for starter cooling before attemptinu another start.

If engine is equipped with purge control system, do not push injector rack control lever (layshaft) until engine has cranked for six seconds. Position layshaft at about one third rack (1.6 on the scale), then turn the Fuel PrimeEngine Start switch to the START position. Hold the switch in the

START position until the engine fires and speed increases. Release the layshaft when the engine comes up to idle speed. Check that the low water detector is not tripped. If the detector is tripped, wait for one half minute after engine start, then press the reset button and hold for five seconds to reset. If the detector trips again, verify engine oil pressure, then slowly push the layshaft in to increase engine speed momentarily before resetting the button. Check that the cooling water level, lube oil pressure, and governor oil level are all satisfactory.

Fuel Storage Facilities Before being added to the fuel tank, it is recommended that diesel fuel be processed through an effective fuel filtration facility that removes soft and hard contaminants 2 microns in size and larger. Using unfiltered fuel can result in suction strainer plugging, loss of performance, and over time, serious damage to injectors.

Soft contaminants include water, bacteria, algae, fungi, and waxes. Water must be removed or kept at the lowest possible level, as it is very destructive to fuel system components. Bacteria, algae, and fungi contamination of the fuel storage tank will show *pc *" up as slime on the facilities fuel filtercand may requirt! treahnent with algicide or fungicide to remove it. Waxes are generally kept in suspension and do not cause problems unless there is an excessively high level of them in the fuel or extremely cold temperatures. $1

Hard contaminants such as rust, scale, cracking catalyst fines, dirt, and wear metals will be removed by the filters as long as they are changed at regular intervals, (usually monthly).

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ITS LocomotiveTraining Series Student Text

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Introduction The engine cooling system consists of engine driven centrifugal water pumps, replaceable inlet water manifolds wit8 an individual jumper line to each liner, cylinder head discharge elbows, and an outlet manifold through which cooling water is circulated. The centrifugal water pumps (one on an 8 cylinder engine) are mounted on the accessory drive housing and are driven by the governor drive gear. A representative illustration of the engine cooling system is shown in Figures 5.1A and 5.1B.

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Figure 5.1A Cooling System Pictorial Diagram ITS Locomotive Training Series - Student Text

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3 Coolant is drawn from the expansion tank through an aspirator by the water pumps. Pump outlet elbows conduct the water from the pumps to the water inlet manifolds located in each air box. Each manifold is connected at the rear end plate to an aftercooler water inlet pipe. Radiators

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Figure 5.1B Cooling System Schematic Diagram

Each cylinder liner is individually supplied with coolant from the water manifold through a water inlet tube assembly. A deflector is used at each liner water inlet to divert the water and prevent direct impingement on the inner liner wall. The coolant flows upward in the cylinder liner water jacket and enters the cylinder head through 12 discharge holes at the top of the liner. A counter-bore around each hole accommodates a heat dam and a water seal. A water discharge elbow is bolted to each cylinder head to provide a water passage to the water discharge manifold which extends along the top of the crankcase. The crankcase has two “built-in” siphon tubes inside the water discharge manifold to provide for engine cooling water draining in the event the enginemnot level.

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Figure 5.1C Coolant Flow through Power Assembly I 5 2

ElectrdvlotiveModel 567,645 & 710 Series Diesel Engines

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In addition to the engine cylinder assemblies, on turbo engines, coolant is also circulated through the aftercooler cores. One condition that has a dramatic effect on engine performance is the temperature of incoming air for combustion.'As inlet air temperature is reduced, engine performance is increased. Past EMD engines used 2 pass aftercoolers as illustrated in Figure 5.2A to cool intake air after it had been compressed by the turbocharger. The coolant was taken off the rear of the main cooling manifolds after the power assemblies.

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Figure 5.2A Two Pass Aftercooler

Figure 5.tB Four Puss Aftercooler

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Coolant temperature for the after coolers therefore was limited to the same level as required for the power assemblies. Because the cores were equipped with only two flanged connections, the coolant flow patterns were different from side to side of the engine resulting in an airbox temperature imbalance between the two banks,

EMD in partnership with Young Radiator has developed a four pass aftercooler which recycles the water through the cooler before discharge to provide a higher cooling capacity. The cores have been equipped with four connection flanges to allow for the application of any four pass core to either the right or left engine bank and keep the coolant pattern the same between banks. Coolant from the power assemblies and the aftercoolers is collected in the main water chamber in the top center of the engine. From the engine, water is directed out the 'Y" pipe to the radiator assemblies. Electrically driven cooling fans move air through the radiators, which absorbs heat from the coolant. Water temperature control is facilitated by the use of temperature switches that control fan and shutter operation. Newer systems use temperature sensors, and fan and shutter control is handled by a microprocessor. The coolant returns from the radiators to the lube oil cooler where it absorbs some of the excess heat from the lube oil. The cooler consists of a radiator section mounted in a steel tank.

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ITS LocomotiveTraining Series - Student Text

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From the cooler, the coolant goes back to the aspirators to repeat the cycle. When the engine is first started, coolant is drawn from the expansion tank as there is no return from the radiators at this point. When there is sufficient return flow, the water level in the tank stabilizes. Note that part of the water from the engine mounted pumps is piped to the air compressor. There are no valves in the line, thus cooling will be provided whenever the engine is running. Upon leaving the air compressor, water is piped back to the water tank for re-circulation

Blower Type Cooling System The cooling system of the blower type engine is identical to the turbo type except for the absence of the aftercoolers and the associated piping. The blower type cooling system is shown in Figure 5.3.

1. W.1.r Pump 2. Outlet Elbow 3. Inlet Manitold

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Figure 5.3 Blower Type Cooling System

Cooling System Pressurization On most newer systems, the cooling system is pressurized to increase the boiling point of the coolant, prevent cavitation at the water pumps during high transient temperature conditions, and to provide uniform cooling throughout the operating range of the diesel engine. The expansion tank has a pressure cap that regulates system pressure at 7,12, or 20 psi (48,82or 138 KPu) depending on engine requirements. Older switcher locomotives and older marine installations use unpressurized systems.

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ElectrMotive Model 567,645 & 71 0 Series Diesel Engines

Operating Water Level An operating water level instruction plate, Fig 5.3, is provided next to the water level sight glass. The instructions indicate minimum and maximum water lever with the engine running or stopped. The water level mark should not be permitted to go below the applicable “low” water level mark. Progressive lowering of the water in the gauge glass indicates a water leak in the cooling system, and should be reported. Normally, there should be no need to add water to the cooling system, except at extended intervals.

Figure 5.4 Water Level Plate

Coolant The coolant is circulated through the engine to transfer heat from the engine components to the radiators. Engine coolant is composed of water, corrosion inhibitor, and when considered necessary, antifreeze. Coolant samples should be taken and analysed at prescribed intervals to maintain the proper solution of corrosion inhibitor.

To be suitable for use in EMD engines, a coolant must meet four basic requirements: adequately transfer heat energy through the cooling system not form scale or sludge deposits prevent corrosion inside the cooling system can’t deteriorate seals or gaskets in the cooling system

Water The water in some areas contain elements such as excessive solids, hardness salts, or corrosive elements such as chlorides that make it unsuitable for use in the cooling systems of EMD engines. Water from these sources should be processed by softening, de-ionizing, or distillation to make it suitable for cooling system use.

Corrosion Inhibitor The main type of corrosion inhibitor for EMD engines is the borate-nitrate type. Borate-nitrate is available in powder, pellet, and liquid form. Powder and pellet form inhibitors should be dissolved in water in a separate container before being added to the cooling system. The level of borate-nitrate should be maintained in a concentration above 5625 parts per million. ITS Locomotive Training Series -Student Text

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Antifreeze

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Specifications for the use of antifreeze in EMD engines is available in M.I. 1748.

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Water Pumps

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Figure 5.5 Water Pump Cross Section

Description The two engine cooling water pumps (one on 8 cylinder engines) are selfdraining centrifugal pumps, which rotate in the opposite direction of the engine crankshaft. The pump drive shaft is supported by two permanently sealed grease lubricated ball bearings which require no maintenance. The components of the water pump are identified in Figure 5.5.

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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The pump seal assembly consists of a carbon inner seal, rubber outer seal, shell, and spring, as shown in Figure 5.6. The rotating rubber outer seal is held against the stationary carbon inner seal by the spring pressure . Any coolant leaking past this sealing face will show externally by leakage at the tell tale drain hole in the drive shaft support housing. In some instances where a pump has been leaking for a long time, the tell tale hole can become plugged with crystalized corrosion inhibitor. When looking for internal water leaks, check to see that the tell tale holes are free of obstruction. The pumps are carried under two part numbers to identify the right and the left bank pumps. The only difference between right and left bank pumps is the position of the impeller housing in relation to the pump shaft housing. The position of the impeller housing may be changed on either pump to permit its use on the opposite bank. To accomplish this, remove the nuts from the impeller housing studs, and separate the impeller housing from the pump shaft housing. For a right bank pump, rotate RigM Hand Left Hand the impeller housing so that the "R" on the impeller housing lines up with the arrow on the pump shaft housing. For a left bank pump, align the "L" with the arrow. Install a new gasket between the impeller housing and the pump shaft housing, apply housing I I I nuts to the studs and torque them to Front End Of Engine I 65 ft-lbs (88Nm).Figure 5.7shows the ---+ .---correct pump housing positioning. Figure 5.6A Pump Housing Positioning I

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Low Water Shutdown. The cooling system is protected against low water situations by the engine protective device. The operation of this device is covered in chapter 9.

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Radiators

44 There are two main types of radiators commonly found on EMD locomotives, the solder bonded core, and the mechanically bonded core. Both are available in single length core 27 inches in length (69 crn),and multi-length core 54 inches in length (137crn).

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Figure 5.7 Typical Radiators

Solder bonded radiator cores have a brass header plate to which the tubes are bonded using a layer of silver solder overlaid with a layer of lead-tin solder.

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Figure 5.8 Flat Tube Solder - Construction Radiator

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/3 3 Electro-MotiveModel 567,645 & 710 Series Diesel Engines A

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Mechanically bonded radiator cores have a steel header plate to which the round tubes are bonded by roller expansion from inside the tube. Mechanically bonded radiators are much stronger than soldered radiators and provide better heat transfer. They can be repaired using phenolic plugs to block leaking tubes or tubes that have become loose from the header.

Header Bolt

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Figure 5.9 Flat -To-Round Mechanical Construction Radiator

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Radiator Inspection and Cleaning Locomotive radiators can be inspected by removing the access covers between the engine room and the radiator compartment. With the engine running check all radiator surfaces, flanges, and piping for leaks, paying special attention to the junction of the radiator tubes to the headers. It is important to properly replace all radiator access covers, as a cover left off will result in improper cooling air circulation, and the slight engineroom pressurization from the main generator cooling air will be lost. Radiators should be cleaned at the interval suggested in the appropriate, or more frequently in areas where there are large amounts of airborne seeds and leaves during certain seasons. Clean the radiators by blowing compressed air through them from the top surface, followed by reverse operation of the cooling fans to clean the cores and radiator compartment. The cooling fans are reversed by interchanging the position of two AC leads bolted to the fan contactor buses in the AC cabinet. The fans are then operated by pressing the test pushbuttons on the engine water temperature switches one at a time, allowing each fan to reach operating speed before pressing another button.

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CAUTION: Be careful not to accidentally release fan test pushbutton during the starting surge of current. Ensure that the AC cables are properly reconnected after radiator cleaning is completed.

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ITS LocomotieTraining Series - Student Text

5-91

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SYSTEM MAINTENANCE

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Maintenance of the cooling system may be divided into two parts; specific checks performed as part of a scheduled maintenance program and items performed as unscheduled checks and repairs. The following are guidelines only based on a preliminary maintenance schedule. Always consult your company’s maintenance instructions for specific inspection items and frequency.

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SCHEDULED MAINTENANCE Daily or Trip Coolant levels must be checked frequently to ensure that the system is functioning normally. Visually check the sight glass on the engine water tank to ensure that the water level is at or near the full mark. If coolant must be added, ensure that the fluid meets the specifications for coolant set out in Maintenance Instruction 1748. Record the amount of coolant added as coolant loss may indicate serious engine problems. Visually examine the system for signs of leakage.

90 Day Inspection In addition to coolant level, the strength of the corrosion inhibitor must be checked to ensure that the internal engine components are adequately protected. Follow the inhibitor manufacturers recommendations or Maintenance Instruction 1748 for the specific concentration required. Take a coolant sample from the sight glass drain valve when the engine is warm and idling. Open the drain valve and allow any accumulated sediment to drain from the glass before capturing the sample. Perform the self test function for the cooling fans with the EM2000. Visually confirm the operation and direction of rotation of the individual blower motors as the test is performed. Inspect all fan contactors and fuses for obvious defects.

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6 Month Inspection

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Radiator segments must be cleaned periodically to remove accumulations of foreign material such as leaves and airborne seeds. With the engine shut down, open all access hatches below the radiator compartment and manually block the shutters open with the magnet valve MVSH. Using a hose and low pressure compressed air, blow through the radiators in the opposite direction to the normal air flow (top of locomotive dowmc)ards).This should dislodge most material lodged in the core. If the buildup is still unacceptable, the radiators may be washed with a pressure washer or removed from the locomotive and cleaned. Refer to the Locomotive Service Manual or M.I. 549 for further details.

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Electro-Motive Model 567,645 & 710 Series Diesel Englnes

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1 Year Inspection

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On an annual basis the magnet valves controlling the radiator shutters should be removed, cleaned and tested to ensure proper operation. M.I. 4707 details this procedure.

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Periodically the cooling system should be pressure tested to ensure that the system is capable of retaining pressure during operation. Inspect and test the pressure caps to ensure that they can hold the system at the correct pressure. Loss of system pressure may result in an overheat situation and engine shutdown. In other cases this loss of pressure may not be enough to cause engine shutdown, but a gradual fatiguing of engine components due to thermal cycling. Procedures for performing these tests may be found in the Locomotive Service Manual.

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After the locomotive has been in service for 1 year, the radiator header screens should be removed, inspected and cleaned to rid the system of any debris present from the manufacturing processes. Some accumulated debris on the screens is a normal situation. Consult M.I. 549 and 550 for further instructions.

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2 Year Inspection On the two year inspection, the pressure caps should be discarded and new caps applied. Ensure that the filler neck is free from cracks or any other damage that may allow a loss of system pressure. Replace the neck assembly if required.

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3 Year Inspection After the unit has been in service for a period of three years, both water pumps should be removed and replaced with qualified components. In addition, all flexible piping connections should be inspected and renewed if required.

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The three year inspection will include removal and replacement of all shutter control and operating components such as magnet valves and air cylinders. Test the system for correct operation when complete. Remove and replace the linking valve assembly with a qualified component, ensuring that both motor and valve portions have been serviced. Cooling fans (blower motors) should be removed and replaced with an EMD unit exchange or equivalent.

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TTS Locomotive Training Series -Student Text A

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3 COOLING SYSTEM TROUBLESHOOTING

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External Water Leaks Use t6e following procedure to check for external leaks on engine reported to be loosing cooling water. With the engine preferably outside running in throttle notch 5 check the following:

3

Walk around the bottom deck of the locomotive and check for any signs of water running down from the top deck paying particular attention to cab heater piping, couplings, cab heater drain valves, and engine air box drains.

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Above deck: Remove all radiator inspection covers and check all radiators for leaks from the cores, rad section joint gaskets, pipe flanges and the radiator vent lines.

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Inspect the Engine Protective Device, low water test valve and line for any signs of water leaks.

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On turbocharged engines, examine the aftercoolers and piping for leaks from flange gaskets and cracked or broken pipes.

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Inspect the engine "veell for water leaks from discharge flanges, marmon couplings or blanking plates. Sometimes water leaking into the "vee" area will flow between the overspeed trip housing and the front plate of the engine block and run down the front and sides of the accessory drive housing.

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Check all cooling water lines connecting the radiators, lube oil cooler, expansion tank, and water pumps for leaking flanges or marmon couplings. Examine the cooling water expansion tank for leaks at the water level sight glass seals, drain cock, and split or rotted hoses on the expansion tank to water pump inlet line connection. 0

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Air compressor water supply and return lines, compressor cylinder heads, cylinder liners, crossover pipe seals, frost plates and plugs, and cylinder has to liner gaskets should all be checked for leaks.

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Examine cab heater supply and return lines in the engine room, main engine drains and cab heater drains in the sump at the front of the engine for leaks. Check both engine water pumps for leaks from inlet flanges, outlet flanges, and the tell tale hole in the back of the pump support housing.

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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Internal Water Leaks: Running After completing the previous checks, return the engine to idle, open all top deck covers and inspect the following areas of all cylinders for water leaks:

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water discharge elbow on the cylinder head from either the head to elbow "0"ring or the elbow to engine block "0"rings.

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Core plugs on the top of the cylinder heads.

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Cylinder head lifting holes (normally full of engine lube oil) Under the injector, which could indicate a crack in the injector well

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Broken head to liner studs (nut missing or water oozing out) The area on top of each cylinder head under the upper left hand crab for cracks, water, or buildup of dried cooling water inhibitor which indicates a crack and leak underneath. Further inspection can be made after the engine is shut down, the crab removed and the area cleaned.

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ITS LocomotiveTraining Series -Student Text

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Seals

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Figure 5.1 1 Heads - Typical Problem Areas

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3 Leakage from a flange or coupling in the engine llveell into the top deck area through the top deck housing to engine block gasket. The water will usually run down to the cylinder head seat ring area, around the cylinder head, and drip off near the cylinder test valve. These leaks should be examined carefully, as they can be mistaken for leaking water elbow "0"rings. Between the head pots, along the bottom edge of the top deck housing, and any visible areas of the engine block for possible cracks.

TEST VALVE CHECK: With the engine running and at idle, open each cylinder test valve one at a time, and check for water being expelled, which indicates either a cracked head, cracked liner, or bad head to liner grommets. 0-6OLB Pressure Gauge

Connection To

Internal Water Leaks,25psi Hydro-Test: After shutting down the engine, open all cylinder test valves, and remove all crankcase and airbox covers. Apply a 25psi (172kPu)hydro-test to the cooling system, using "city"water pressure and an adapter with a valve and gauge installed in the cooling system pressure cap bell housing. Open the valve and gradually increase the pressure until 25psi is reached then close the valve. If pressure drops off rapidly, there probably is a large leak (internalor external) that will have to be repaired before further checks can be made.

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Figure 5.11A Hydntatic Test Equipment

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I514

Electro-tvlotive Model 567.645 & 710 Series Diesel Engines

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Once 25psi is maintained (or slow leak off) bar the engine over and check each power assembly internally with the piston at the bottom of its stroke for the following: water on the piston crown or running down the inside of the liner, indicating a cracked liner, cracked cylinder head, or internally leaking grommets. When a leak is found, check the ''veer' of the engine for water, as a leak in this area can leak under the exhaust manifold gasket, down the exhaust port, through an open valve and be mistaken for an internal water leak. Water on the piston crown or running down the inside of the liner may also come from a cracked block in the exhaust scroll area where the exhaust port is welded to the engine top plate. The water will run down the exhaust port into the cylinder head, through an open exhaust valve into the liner. After internally checking each power assembly, at the same time, 'make the following external checks: water running down the outside of the liner from cracks on the outside of the liner, leaking grommets, or core plugs on the sides of the head or liner. Water from the l'veell can also show up as running down the outside of the liner. Leaks from water jumper lines from cracks, water jumper to liner flange seal, or water jumper to water manifold flange gasket.

Check through each crankcase cover for water dripping from the bottom of the liner into the oil. Check the bottom of the upper water passage in the block for signs of cracks (b>, looking up beside each liner through the inner air box opening). Check the water manifolds the entire length of the engine both sides for cracks or leaking "0"rings.

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ITS Locomotive Training Series -Student Text

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Drain the lube oil strainer housing (by rifling and turning strainer housing druin valve), when the oil level drops below the oil cooler inlet line check for water running down from the lube oil cooler. On turbo engines, check the aftercooler cores for leaks. If equipped with a exhaust manifold screen inspection port, check turbo screen and exhaust manifold for signs of dried corrosion inhibitor or "washed" areas. After making all these checks, and no leaks are found, it may be necessary to a hot water 2Spsi hydro-test. Drain the engine, refill with hot water apply 2 5psi water pressure, and repeat all the proceeding checks.

Block Check, Power Assembly Removed: On some occasions a suspected leaking power assembly will be removed, and after examination, no obvious cause of the leak is found. Inspect the exhaust port for a crack, dried coolant inhibitor, or water. If nothing is found, apply a blanking saddle to the water manifold outlet of the removed assembly and an expansion plug to the water discharge hole in the block. Refill the engine with hot water, reapply the 25psi hydro test, and check for water leaking down the exhaust port. If water is seen running down the exhaust port but the source cannot be seen, the exhaust manifold section for that cylinder will have to be removed to locate and repair the leak (usually u crack in the exhaust scroll to engine top plate weld).

Figure 5.13 "Blanking Saddle" and "Expansion Plug"

9Opsi Block Test In some cases, where an engine has been inspected with 25psi cold and hot hydrotests, and no water leaks are found, it becomes necessary to apply a 9Opsi (620kPa) test to the isolated engine block. Usually this is done when an engine has a history of oil contaminated by water, or loosing water with no leaks being found.

516

Electro-MotiveModel 567, 645 & 71 0 Series Diesel Engines

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High Coolant Temperature On an engine experiencing high coolant temperature, make the following suggested checks: Check the coolant level in the expansion tank, and refill if low. If the engine is continually using cooling water check for internal and external water leaks. 0

Veri@that the shutters are operating properly using the temperature switch test button. Check the temperature switch operation by running the engine until the switch closes, or by removing the switch and testing it in a pan of heated water with a thermometer.

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Check for the proper operation of all cooling fan motors and temperature control switches. Remove the radiator access panels and inspect all radiators for restriction of air flow. Clean the radiators if necessary using the procedure on Pg.5-8. 0

Inspect all water pump and radiator vent lines for proper connection, loose fittings, or damage to the lines. Loose water pump vent lines can cause cavitation of the water pump and a resulting loss of coolant delivery pressure. Damaged or improperly connected radiator vent lines can cause air binding in the radiators resulting in a loss of cooling efficiency.

Low Coolant Pressure Low coolant pressure can be a cause of high coolant temperature. Install a pressure gauge in the expansion tank and run the engine until it reaches operating temperature. Compare the gauge reading to the pressure stamped into the expansion tank pressure cap. If the pressure is low, make the following checks. Test the expansion tank vent valve by placing the end of the expansion tank vent line in a bucket of water. If bubbles are released through the water, the expansion tank vent valve is not seating properly and must be replaced.

With the engine shut down and the cooling system pressure relieved by opening the manual vent valve, remove the pressure cap and inspect the filler neck. If the sealing surface is damaged or distorted, replace the neck assembly with a new one using a new tank to neck gasket. Inspect the pressure cap for proper seating of the snifter valve, and check for a cracked, hardened or damaged gasket. Test the cap on an external pressure tester. Replace the cap if any defects are noted.

I518

Electrdvloti Model 567.645 81710 Series Diesel Engines

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Lube Oil System

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Introduction

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The complete engine lubricating oil system is a combination of three separate systems. These are the main lubricating system, the piston cooling system and the scavenging oil system. Turbocharged engines use a fourth system, the soak back or turbo lube system. Another oil system that is available as an option or as an upgrade is the self contained pre-lube system.

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Each system has its own oil pump. The main lube oil pump and piston cooling oil pump, although individual pumps, are both contained in one housing and driven from a common drive shaft. The scavenging oil pump is a separate pump, as is the turbo lube pump.

The main lube, piston cooling, and scavenging oil pumps are driven from the accessory gear train at the front of the engine. Parts of the complete oil system and a schematic arrangement of oil circulation are shown in Figures 6.1A for a turbocharged engine, and 6.1b for a blower type engine on the following two pages.

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IlS Locomotive Training Series - Student Text

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2. Oil Sttainer Housing 3. Main Lube Oil and Piston Cooling Oil Purnr, 4. Oil Line TO GWCK~W Wve GmrSbrb.h.ft 5. Main Lube Oil and Pinon Cooling oil M M M d 6. Oil Pnuure Relief V&a

Figure 6.1A Turbocharged Engine Lube Oil System

7. Oil P m u u n Line To Govemor 8. Cun.h.tt Oil P u u g e (lo Camehaft Baring. M d Cylinder Rocker Anna) 9. Soak Back Filter 10. Turbocharger FilW 11. Turbochugr Filter Oil Supply M ~ l t o l d 12. Oil Line To Right and Left Bank CMUMI Ddve and To Turbo Filter 13. Oil Linm To Camshaft Stubshaft8 14. Oil Line to No. 2 Idler Qu - Stubshaft - ~~- - . 15. Turbochugor &r Train 18. Turbochuger B d n g Oil Supply Linw 17. Oil Line to No. 1 Idler G u Stubohaft 18. M.in Oil Manifold 18. Oil Supply to Cnnkrhn M d Buringa 20. Piston Cooling oii Line

Main Lubricating System The main lubricating oil system supplies oil under pressure to most of the moving parts of the engine. The main lube oil pump takes oil from the strainer housing at the right front of the engine. Oil from the pump goes into the main oil manifold which is located above the crankshaft, and extends the length of the engine. Maximum oil pressure is limited by a relief valve in the passage between the pump and the main oil manifold.

Oil tubes at the center of each main bearing “A” frame conduct oil from the main manifold to the upper half of the main crankshaft bearings. Drilled passages in the crankshaft supply oil to the connecting rod bearings, torsional damper, and accessory drive gear at the front of the crankshaft. Leak-off oil from the adjacent main bearings lubricates the crankshaft thrust bearings. Oil from the manifold enters the gear train at the rear of the engine, at the idler gear stubshaft. Oil passages in the base of the stubshaft distribute the oil. One passage conducts oil upward to the left bank camshaft drive gear stubshaft bracket through a jumper, and downward to the lower idler gear stubshaft and bearing. Another passage conducts oil to the right bank camshaft drive stubshaft bracket and on to the turbocharger oil filter supply line. After passing through the filter, the oil enters the return line, returning to the upper idler gear stubshaft bore and bearing. Filtered oil enters the turbocharger oil system from the upper idler gear stubshaft. An oil pressure line connects to the top of the turbocharger oil manifold, adjoining the filter. This oil line goes to the low oil pressure device in the governor.

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ElectroMotive Model 567,645 & 710 Series Diesel Engines

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Scavenging Oil System The scavenging oil system pump, takes oil through the scavenging oil strainer from the oil pan su~fipor reservoir. The pump then forces the oil through the oil filters and oil cooler which are located near the engine. Oil then returns to the strainer housing to supply the main lube oil pump and piston cooling pump with cooled and filtered oil Excess oil spills over a dam in the strainer housing and returns to the oil pan.

Oil Gauge An oil level gauge, Fig. 6.2,

extends from the side of the oil pan into the oil pan sump. The oil level should be maintained between the low and full marks on the gauge, with the reading taken when the engine is at idle speed and the oil is hot.

Lubricating Oil Pressure Adequate lubricating oil pressure must be maintained at all times when the engine is running. Upon starting and idling an engine, it should be noted that the oil pressure builds up almost Figure 6.2 Oil Level Gauge immediately. In the event of cold oil, the pressure may rise to the relief valve setting of approximately 125 psi (862 P a ) . Lubricating oil pressure is not adjustable. The operating pressure range is determined by such things as manufacturing tolerances, oil temperature, oil dilution, wear, and engine speed. The pipe plug can be removed from the opening in the pump discharge elbow and a gauge installed to determine the pressure. The minimum oil pressure is approximately 8-12 psi (55.1 - 83 kPu) at idle and 25-29 psi ( I 72 - 200 kPu) at full speed. In the event of insufficient oil pressure, a shutdown feature built into the governor will automatically protect the engine by shutting it down. Maximum pressure is determined by the relief valve setting of 125 psi ..(862kPu)for 645 E3 and later engines, 60 p i (4!4 kPu) for 567 and 645E engines. b

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Piston Cooling Oil Pressure

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Pressure of the piston cooling oil will be governed by oil viscosity, speed of engine, temperature of oil, and wear of pump parts. The pipe plug can be removed from the opening in the pump discharge elbow and a gauge installed to determine the pressure.

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ElectreMotive Model 567.645 & 710 Series Diesel Engines

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Scavenging OiI Strainer (Coarse) Figure 6.3 shows the scavenging oil strainer (coarse) removed. The strainer is installed in the housing and all oil for the scavenging system is drawn through it. The function of the strainer is to protect the scavenging pump from foreign material damage. Since the strainer is on the suction side of the scavenging pump, improper application may cause the engine to shut down for low lube oil pressure, usually under load conditions.

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Figure 6.3 Scavenging Oil Pump Strainer

Scavenging Oil Pump The scavenging oil pump, Fig. 6.4, is a positive displacement, helical gear type pump. The pump body, split transversely for ease of maintenance, contains sets of mated pumping gears. The driving gears are retained on the pump drive gear shaft by Woodruff keys. The idler shaft is held stationary in the housing by a set screw, and the driven pump gears rotate on this shaft on bushings pressed into the gear bores. The drive shaft turns in bushings pressed into the pump body. These bushings are made with thrust collars which protrude slightly above the pump body and absorb the thrust of the drive gears. The scavenging pump is mounted on the accessory housing in line with, and to the left of the crankshaft, and is driven by the accessory drive gear. Design of the scavenging oil pump is similar to the main lube oil and piston cooling oil pump, except for the use of the spacer in the main oil pump.

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Pump Capacity (Approx. GPM)

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Lube Oil Filter Michiana Four & Seven Element Tanks Proper filtration of lubricating oil is essential to engine life and efficient, reliable operation.

To fully realize the importance of adequate filter maintenance, it is helpful to understand the full flow lube oil system. Full flow filtration ensures that all the lubricating oil is filtered before it is supplied to the engine. A bypass valve is provided in the filter tank, however, and will open and bypass lube oil around the filter elements during conditions of cold oil start, or when filter elements are plugged. Figure 6.5 Lube Oil Filter Tank 6 Cooler

The filter bypass valve ensures adequate lube oil to the engine, and prevents excessive scavenging oil pump outlet pressures. The valve opens at differential pressures above: *c

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30 psi (207 kPu) - 567 engine 40 psi (275 kPa) - 645 and 710 engines

If lube oil filters become plugged, it is likely that the turbo filter will plug in short period of time and cause a low oil pressure shutdown of the engine.

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Pump Capacity (Approx. GPM)

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71OG3 Engines at 900 mm

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Lube Oil Filter Michiana Four & Seven Element Tanks Proper filtration of lubricating oil is essential to engine life and efficient, reliable operation.

To fully realize the importance of adequate filter maintenance, it is helpful to understand the full flow lube oil system. Full flow filtration ensures that all the lubricating oil is filtered before it is supplied to the engine. A bypass valve is provided in the filter tank, however, and will open and bypass lube oil around the filter elements during conditions of cold oil start, or when filter elements are plugged. Figure 6.5 Lube Oil Filter Tank 6 Cooler

The filter bypass valve ensures adequate lube oil to the engine, and prevents excessive scavenging oil pump outlet pressures. The valve opens at differential pressures above: cc

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30 psi (207 kPa) - 567 engine 40 psi (275 kPa) - 645 and 710 engines

If lube oil filters become plugged, it is likely that the turbo filter will plug in short period of time and cause a low oil pressure shutdown of the engine.

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Electro-Motive Model 567, 645 & 710 Series Diesel Engines

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Lube Oil Cooler The oil cooler assembly, also shown in Figure 6.5, and Figure 6.6 is representative of the late model installations, is positioned at an angle in the equipment rack adjacent to the front end of the engine.

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Q The external construction of the oil cooler consists of a fabricated steel oil tank surrounding the oil cooler core. Inlet header assemblies are located near the top of the enclosure for entry of water to the upper radiator header.

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The coolant returning from the radiators enters the cooler through flanged connections at the top of the cooler, flows through the cooler tubes and is discharged through flanged connections at the bottom of the cooler. The lubricating oil enters the shell space through a flanged connection near one end of the cooler, flows transversely around the tubes and around the end of the baffles, and leaves the shell through a flanged connection near the opposite end of the cooler. The coolant and the oil flow through the cooler in Figure 6.5A Fin and Tube Oil opposite directions to produce the maximum CooZer Cores cooling effect. soldered left, mechanically ToZZed right

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Lube Oil Strainer Housing An oil level is maintained in the strainer housing up to the bottom of the overflow opening by the scavenging system. This oil serves as the supply for the main lube and piston cooling systems. Excess oil not used by these systems returns to the engine sump. A spring loaded valve is provided to drain the oil from the strainer housing into the engine sump for strainer maintenance. An additional valve is used to drain the oil filter housing. Both of these valves are located under the filler cover. Normally oil is added to the engine by strainer housing.

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ITS LocomotiveTraining Series Student Text

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Main and Piston Cooling Oil Pump Strainers (Fine) One of the two main lube oil pump strainers is shown removed from housing, Figure 6.7. When in place, they are held by a crab and hand wheel on the stud between the holes. Each strainer is sealed at the top by a “0” ring seal. The engine lube oil strainers have oil pressure around the O-rings to assist in sealing. The oil under pressure will leak out under the strainer flanges if the seal rings are not sealed properly or are damaged.

Figure 6.7 Main 6 Piston Cooling Pump Strainers

The current design two-piece main lube oil pump strainers each consist of a replaceable element of a pleated perforated metal core covered with mesh screening, and a metal cylinder which encloses the element.

This cylinder prevents collapse of the element in the event of a high pressure drop. The element is attached to the cylinder by a through bolt in the cylinder which runs through the base of the element and is secured with a locknut. The unperforated outer cylinder provides a constant head of oil since suction is from the bottom only and not through the entire length of the screen. Oil flow is from the bottom of the strainer between the cylinder and the mesh screen, through the mesh screen and the perforated metal core into the center of the element, then out the top of the strainer.

Main Lube Oil and Piston Cooling Pump

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The main lube oil and piston cooling oil pumps shown in Figure 6.8, are contained in one housing. The two pumps are separated by a spacer plate between the sections of the pump body. Each has an individual oil inlet and discharge opening. Piston cooling pump gears at the end are narrower than the lube oil pump gears. The lube oil and piston cooling oil pump assembly is mounted in the center of the accessory drive housing, and is driven by the accessory drive gear.

ElectroMotive Model 567,645 & 710 Seriis Diesel Engines

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Pumps are designed and built in sections, to increase pump capacities for larger horsepower engines. For example, the 567 main lube pump is equipped with only two helical gears, while the 6 4 5 and 710 main lube pumps are equipped with four helical gears.

Pump Capacity

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5678835rpm

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108

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710 G3 8 900 rpm

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The lube oil pressure relief valve illustrated in Figure 6.9, is installed on the lube oil crossover manifold, inside the accessory gear train housing on the left side of the engine. This valve is accessible for inspection and service by removing the Engine Protection Device, or access plate on engines not equipped with EPD. The purpose of the valve is to limit the maximum pressure of the lube oil entering the engine oil system. When the lube oil pump pressure exceeds the spring tension on the valve, the valve will be lifted off its seat and relieve the excess pressure. This oil drains into the accessory housing and then into the oil pan.

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Figure 6.9 Lube Oil Pressure Relief Valve

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Turbocharger Oil Filter Description The turbocharger oil filter, Fig. 6.10, provides additional protection for the high speed bearings and other lubricated areas of the turbocharger, by filtering the oil just before it is admitted to the turbocharger.

Oil enters the filter through a cast manifold and, after passing through the filter, returns to the upper idler gear stubshaft and into the turbocharger. The filter element is of pleated paper construction, and is disposable. The filter is mounted on the camshaft drive housing at the right bank of the engine. Newer engines have a disposable spin on type turbo lube filter. Always fill both types of filters with clean oil before installing on the engine.

Figure 6.10 Turbocharger Oil Filter

Soak Back Oil System To ensure lubrication of the turbocharger bearings prior to engine start, and the removal of residual heat from the turbo after engine shutdown, a separate lube oil pressure source is provided, refer to figure 6.1. This pressure system is controlled automatically by the locomotive control system. An electrically driven pump draws lube oil from the oil pan, pumps the oil through a filter and the head of the turbocharger oil filter directly into the turbocharger bearing area. The motor driven pump and filter are mounted on the side of the oil pan on the right bank of the engine.

A 5 5 psi pressure relief valve, located in the head of the filter, controls the system pressure. Also located in the filter head is a bypass valve set for 70 psi. This valve will open to permit oil from the soak back pump to bypass a filter element so lubrication can be supplied to the turbocharger to prevent turbo damage.

Soak Back Filter Pressure Switch Some engines are equipped with a soak back filter pressure switch that will inhibit starting of the diesel engine until the turbo lube system is pressurized.

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ElectmMotive Model 567, 645 & 710 Series Diesel Engines

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3 Lube Oil Separator (Turbo, Air Ejector System)

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In applications that cause back pressure in the exhaust system, such as exhaust silencers or extended exhaust piping runs, an air ejector system is used to increase crankcase vacuum.

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Pressurized air from the left bank aftercooler duct is piped to the ejector, where it blows through a venturi, adding to the suction created by the eductor tube. Different size ejector nozzles are available to aid in maintaining proper crankcase suction levels. To increase crankcase suction, apply a large diameter Figure 6.13 Ejector System nozzle, but only after inspecting the engine for other causes of low vacuum. Oil droplets collect in the lube oil separator, and drain back to the crankcase, while the vapors discharge into the exhaust and are vented to the atmosphere.

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SYSTEM MAINTENANCE Y)

Maintenance of the lube oil system normally consists of a few minor tasks performed as part of a scheduled maintenance program, however there are certain additional tasks that may be required when unscheduled repairs are performed or the unit has been stored.

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SCHEDULED MAINTENANCE

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3 The lube oil level should be checked frequently to ensure that the engins has an adequate supply for lubrication and cooling. Low oil levels can lead to high oil temperatures as well as low oil pressure. Visually check the dip stick on the right bank of the engine to ensure that the oil level is at or near the full mark. Also note the presence of:

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Fuel vapours that could indicate internal fuel leaks;

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Grey sludge that could indicate internal water leaks.

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If oil must be added, ensure that the fluid meets the specifications for lubricating oils set out in Maintenance Instruction 1752. Oil is added to the diesel engine through the fill port located above the main water pump (front right corner). Ensure that the area is clean before opening the cap and replace securely when finished. Record the amount of oil added as a high consumption rate may indicate serious engine problems. Visually examine the system for any signs of leakage.

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90 Day Inspection In addition to oil level, the condition of the oil must be checked for any indications of problems with the internal engine components. The oil is to be checked for:

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Viscosity (internal fiel leaks) Take a sample of engine oil for analysis from the test fitting located at the main lube pump. Ensure that a clean container is used for the sample to avoid incorrect test results. Follow the recommendations of Maintenance Instruction 1752 for the specific condemning limits of the lubricating oil and any recommended checks or tests if unusual results are found. At 90 days, the main oil filters should be renewed. With the engine shut down, open the lube oil filter tank drain valve and allow the oil to drain back into the engine sump before opening the access doors. Remove the filter elements, thoroughly clean the tanks and renew the 8 paper elements. Apply new seals and secure the access doors. Note: Do not forget to close the filter tank drain valve! The turbo lube and soak back filters are also renewed on the 90 day inspection. Pre-fill both elements with clean engine lube oil before applying to the engine. This procedure has not been altered from previous design engines. The strainer housing has been replaced on this engine by a single strainer element located on the front of the diesel engine beside the main lube pump. Remove the strainer cover and withdraw the element from the housing. Inspect the element and the bottom of the housing for debris, clean as required. Reapply the strainer element and cover using a new gasket.

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TTS Locomotive Training Series -.StudentText

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On an annual basis the following additional check should be made to ensure proper operation of the lube oil system. Open the left rear crankcase inspection cover and the rear top deck covers. Initiate the turbo lube pump sequence and ensure proper system operation. With the pump running, there should be a steady flow of lube oil returning to the engine sump down the rear gear train housing. There should be no oil flow from the crankshaft or camshafts. Oil flow in this area would indicate faulty check valves in the turbo filter head. Remove the filter head and service check valves as required. Specific instructions may be found in the Engine Maintenance Manual.

2 Year Inspection After the locomotive has been in service for 2 years, the temperature differential between the lube oil and cooling water entering the engine should be checked. If the differential is outside the prescribed service limits indicated in MI 928, the cooler will have to be cleaned or replaced with a qualified unit. Note that this check is performed as part of a load test.

3 Year Inspection On the 3 year inspection, remove the main lube oil filter bypass valve. Clean, inspect and test the valve before reinstalling. The procedures for servicing this valve may be found in MI 926. Remove the turbo lube filter head assembly, clean, inspect and qualify the check valves as per the procedures indicated in the Engine Maintenance Manual. Ensure that the system is checked for proper operation before returning the locomotive to service.

6 Year Inspection The 6 year inspection is the major inspection interval. This inspection will require the removal of the main lube oil pump and oil pressure relief valve. Replace these components with qualified units. Remove, clean and inspect the soak back filter head assembly. Pay close attention to the bypass ball valves, replace if required. Remove and recondition soak back pump and motor. Check system operation before dispatching locomotive.

Lube Oil System Troubleshooting Problems with the lube oil system generally can be classed as one of two types; (1) a loss of oil pressure or (2) high oil temperatures.

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Low Oil Pressure - Non EMDEC Engine lube oil pressure is determined by manufacturing tolerances, oil temperature, oil condition, engine wear, and engine speed. Minimum oil pressure is 812psi (55-83kPu)at idle, and 25-29psi at full speed. If oil pressure falls below these levels, the low lube oil shutdown on the Woodward governor will shut the engine down. Low lube oil shutdown by the governor is also initiated by the hot oil detector, E.P.D. low cooling water portion, or E.P.D. crankcase pressure portion. When an engine is reported as having low oil pressure, the following steps should be taken: Check the engine lube oil level, add oil if low. Take a lube oil sample to check for proper oil viscosity. Low oil viscosity caused by a condition such as internal fuel leakage will have a dramatic negative effect on oil pressure. Follow directions on page4-20 for finding internal fuel leaks. Note the engine water and oil temperature. As with fuel leaks, a high oil temperature will lower the oil's viscosity and therefore the oil pressure. Should the oil temperature be above a normal range, qualify the cooling system, the lube oil cooler efficiency and perform an internal inspection of the engine sump looking for signs of overheating, and loose or missing components. Remove the 314" pipe plug in the main lube oil pump discharge elbow and install a 0 - 150 PSI test oil gauge in the outlet elbow of the main lube oil pump. If the oil pump pressure is low, proceed with the following checks. If the pump pressure is adequate, proceed to "Test gauge

reading adequate". Remove and clean the two fine screen strainers in the strainer housing. Inspect the seals and blow compressed air through the seal vent line to make sure it is not obstructed. Drain the strainer housingusing the strainer housing drain valve and inspect for foreign material. Check for suction leaks at the flanges of the main lube oil pump inlet elbow at both the pump and strainer housing ends. Replace gaskets where necessary. Change the turbocharger oil filter element. A clogged or upside down element cancause low oil pressure in the line to the governor, causing the engine to shut down. Remove the Engine Protection Device from the engine, (ifequipped), leaving the oil lines connected, and move it to the side. Check the oil pressure relief valve for excessive oil leakage from the relief port indicating the valve is stuck in the open position. If so, remove the oil pressure relief valve and replace it with a qualified unit. Also check for excessive lube oil flow from any other source.

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Remove all crankcase covers and inspect the piston pins and external surfaces of the main and connecting rods for signs of overheating and missing or loose components.

If nothing is found in the above checks, remove and qualify the main lube oil pump

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Test gauge reading adequate: Remove and qualify the main engine oil pressure gauge or replace it with aqualified unit. Check the 1/8" diameter oil supply line in the right bank top deck of the engine for damage and blow air through it to make sure it is clear of obstructions.

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Disconnect and block the connecting line from the oil pressure sensing line to the Engine Protection Device and hot oil detector. Start the engine, if oil pressure is restored, either the EPD or hot oil detector is defective. Remove and qualify both devices as per instructions in the Engine Maintenance Manual. Use the recommended tool and procedure in the EMM to check the clearance of the Number 1 idler stubshaft bushing. Excessive clearance will cause a low pressure reading. Inspect the interior of the end housing for debris under the rear gear train. On turbo engines, remove the auxiliary generator drive (OT cover prate i f not equipped), and check the manifold to the turbo filter for cracks,loose or missing components or seals. Inspect the camshaft supply manifolds, and ensure that the upper pipe plug is installed in the gauge line connecting block. On blower engines, remove the auxiliary generator drive (OT oil separator housing if not equipped). Inspect the oil jumper lines to the camshaft bearing brackets for loose or missing components or seals.

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Low Oil Pressure - EMDEC Engine lube oil pressure and temperature is constantly monitored by the EMDEC control unit through the use of the pressure sensor located at the turbo filter head and the temperature probe located at the main oil inlet on 8,12, and 16 cylinder engines, and the oil inlet "Y" pipe on 20 cylinder engines. This information is relayed also to the EM2000 for display on the screen. Should either condition move outside of normal operating ranges, EMDEC will cause an engine shutdown and display a fault condition, Thus EMDEC performs the function of the low lube oil shutdown on the Woodward governor and the function of the hot oil detector on older engines. When an engine is reported as having low oil pressure, the following steps should be taken immediately: 0

Take a lube oil sample to check for proper oil viscosity. Low oil viscosity caused by a condition such as internal fuel leakage will have a dramatic negative effect on oil pressure. Determine whether the problem is actually low pressure, or an incorrect reading by the pressure transducer. Fit a mechanical gauge to the pressure sensor location using a "Tee" fitting. When the engine is operating, the gauge and the reading indicated by the sensor should be within a few pounds of each other. If not, replace the sensor with a qualified unit. Note the engine water and oil temperature. As with fuel leaks, a high oil temperature will lower the oil's viscosity and therefore the oil pressure. Should the oil temperature be above a normal range, qualify the cooling system, the lube oil cooler efficiency and perform an internal inspection of the engine sump for possible bearing distress.

If the mechanical gauge indicates a true low pressure situation, the procedures for qualifying the system remain the same as in the past, however, note closely the condition of the following: Suction strainer cover gasket. Pressure differential across the main lube filters. Position of lube oil filter drain valve. Inlet pressure to engine at "Y" pipe. Condition of piston cooling pipes. It is very easy to break the system down into specific areas by simply looking at the pressure of the oil leaving the main lube pump, entering the engine, and at the turbo filter head. For example, if there is little pressure leaving the main pump, then the problem is likely on the suction side of the pump or the pump itself. Further, if the pressure drops dramatically across the filters, then one would suspect a problem in th'is area.

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Lack of Oil Delivery From Scavenging System The first step in troubleshooting the scavenging oil system is to install a 0 - 50 PSI pressure gauge in the quick disconnect fitting on the Michiana filter tank. Prelube the engine if necessary. This procedure is for all installations except marine engines with engine mounted raw water pumps. Before starting the engine: Check engine oil level. Ensure the strainer housing is full to within 5 lmm (2") of the screen under the large cover. Make sure the Michiana tank drain valve (Thandle) is fully closed . Remove and clean the scavenging pump course strainer element which is held in the strainer box by three bolts. Check the interior of the strainer housing for foreign material and clean if necessary. Reinstall the clean strainer element in the housing with a new gasket, and tighten securely. Remove the crankcase covers at the right front of the engine and inspect the full length of the scavenging oil suction line from the front end of the engine to the oil sump for cracks or mechanical damage from broken connecting rods or pistons. Repair any damage before starting engine. After starting the engine, check to see if the oil level in the strainer box returns to approximately 51 mm (2") of the screen within 45 seconds. If it does not, take a pressure reading at the Michiana tank with the engine at idle and do the following checks. If the strainer box does refill, proceed to checks under "Strainer Box Refills".

If the pressure reading was low or zero, either the scavenging pump is defective or there is a suction leak in the suction line to the strainer box. Remove and overhaul scavenging pump if necessary.

If the pressure reading was higher than 69 kPa (IOpsi),change the oil filter elements, then repeat the test. If the pressure is still over 69 kPa (IOpsi), remove and clean the oil cooler.

Strainer Box Refills If the strainer box refills, slowly increase engine RPM to full speed. At full speed take a reading of the gauge on the Michiana tank. If the pressure reading is above 172kPa (25psi),change the filter elements. O n switcher locomotives and industrial engines with tube bundle and shell type oil coolers, the changeout pressure reading is 172 P a (SO psi). Take the pressure reading again. If the pressure is 69kPa (lopsi) switcher industrial 138kPa [20 psi] or more, temperature test the oil cooler using the procedure in "High oil Temperature" section. If indicated, remove and clean the oil cooler. I618

ElectroMotive Model 567,645 81710 Series Diesel Englnes

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remove the bypass valve from the Michiana tank and determine if it is jammed open.

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If the pressure reading is 2lkPa (3psi) switcher - industrial 69kPa [ 10 psi],

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WARNING: When an engine shuts down due to hot oil, wait at least 2 hours before attempting to inspect the engine. Opening engine covers and admitting fresh air when the oil vapours inside the engine are hot could cause an explosion. Follow these suggested steps to find the cause of a hot oil shutdown.

Check oil level in the oil pan and monitor oil pressure on the engine lube oil pressure gauge Verify that there is delivery of oil from the scavenging oil system (See Lack of delivery fiom scavenging system). Determine if there is a high cooling water temperature problem, as high cooling water temperature will cause high oil temperature. (See Chapter 5 for cooling system troubleshooting).

If the engine is equipped with a thermostatic temperature control valve (marine and stationary power upplications), verify the opening of the valve. Failure of the valve to open can deprive the oil cooler of cooling water. Temperature test the oil cooler by installing temporary thermometers in the wells provided in the cooling water piping. Run the engine and monitor temperatures in and out of both the oil and water sides of the oil cooler. Compare these readings with a standard chart on locomotive installations, or installation records on marine and stationary power. If oil temperature drop or coolant temperature rise values are not adequate, remove the oil cooler for inspection and cleaning ( i f necessary). Remove all crankcase covers and inspect for signs of overheated surfaces or extruded bearing material around the main and connecting rod bearings. Inspect under the front and rear gear trains for metal debris.

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High Oil Temperature EMDEC Normally there is a close relationship between engine coolant temperature and engine lube oil temperature. EMDEC monitors lube oil temperature as the oil enters the engine. If the temperature of this oil exceeds approximately 124" C (255"F), EMDEC will cause an engine shutdown and communicate the fault to the EM2000 control computer.

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Replace any defective components, then load test the engine. If oil loss continues, proceed with the following checks: Disassemble the lube oil separator and check for a missing or disintegrated screen. Replace if missing. The absence of this screen can cause excessive oil consumption and oil out the stack. Loss of crankcase vacuum due to combustion gases from a cracked piston, pressurized air box air via bad lower liner seals, or ambient air through a loose crankcase cover can cause a flow rate that exceeds the separator screens' ability to filter out oil droplets. Check crankcase vacuum with a manometer and correct any defective conditions found. Remove the turbocharger screen and inspect the exhaust manifold for manifold legs coated with oil. Change the power assembly or assemblies in the cylinders indicated by the oil coated manifold legs. If the exhaust stack is excessively covered in oil so it is impossible to tell which cylinder the oil is coming from, in may be necessary to load test the engine to dry out the exhaust manifold, then repeat the check.

If no oil is found in the exhaust manifold, the problem is most likely in the turbocharger. Check the turbo air intake filters for signs of plugging. Plugged filters can cause high inlet vacuum and draw oil past the turbocharger labyrinth seals. See the Turbocharger section of this manual for the procedure to qualify a turbo for changeout. Worn or pounded head retainer surfaces, or pounded head seat rings due to improperly torqued head crab nuts can create clearance which allows oil to be drawn past the head seat ring and into the exhaust. These conditions can be minimized by following the appropriate Scheduled Maintenance program for checking crab nut torques, and by following proper crab nut torquing procedures when changing power assemblies. Engines operated for extended periods of time under light or no load may experience varnishing, (light brown or tan deposits) of the cylinder walls. This condition reduces the effectiveness of the oil rings and can lead to a condition called "souping'l, or oil loss out the exhaust. If light load operation is continued, the varnish deposits can interfere with the ring to liner seal effectiveness. To remove these deposits it may be necessary to load the engine by either a change of service or the use of a load box to remove the deposits.

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Prelubrication of Engines Prelubrication of a new engine, an engine that has been overhauled, or an engine which has been inoperative for more than 48 hours is a necessary and important practice. Prelubrication alleviates loading of unlubricated engine parts during the interval when the lube oil pump is filling the passages with oil. It also offers protection by giving visual evidence that oil distribution in the engine is satisfactory. Perform prelubrication as follows:

1.

Remove the pipe plug at the main lube oil pump discharge elbow, and connect an external source of clean, warm oil at the discharge elbow. Prelube engine at a minimum of 69 kPa (1Opsi) for a period of not less than three and not more than five minutes (approximately 57 lpm or 15 gpm) using a 1.1 to 1.5kW (1.5 to 2 hp) motor.

2.

While oil pressure is being applied, open the cylinder test valves and bar the engine over one complete revolution. Check all bearings at the crankshaft, camshafts, rocker arms, and at the rear gear train for oil flow. Also check for restrictions and excessive oil flow. If fluid discharge is observed from any cylinder test valve, find the cause and make the necessary repairs.

3.

On new or overhauled engines, remove the pipe plug at the piston cooling oil pump discharge elbow and connect the external oil source at that opening. Check for unrestricted oil flow at each piston cooling oil pipe.

4.

Disconnect the external oil source and replace the pipe plugs at the pump discharge elbows. Close the cylinder test valves.

5.

Pour a liberal quantity of oil over the cylinder head mechanisms of each bank.

6.

Check oil level in the strainer housing and, if required, add oil to the strainer housing until it overflows into the oil pan.

7.

Replace and securely close all handhole covers and engine top deck covers.

When an engine is replaced due to mechanical breakdown, it is important that the entire oil system, such as oil coolers, filters, and strainers, be thoroughly cleaned before a replacement engine or reconditioned engine is put in service. A recurrence of trouble may be experienced in the clean engine if other system components have been neglected. In some cases engines have Sezz rcnoved from service and stored in the "as is" condition by draining and applying anti-rust compound. When these engines are returned to service, care must be taken to see that any loose deposits are flushed out before adding a new oil charge. The entire engine should be sprayed with fuel to break up any sludge deposits, and then drained, being careful that the drains are not plugged. Fuel should not be sprayed directly on the valve mechanism or bearings, as lubrication will be removed or dirt forced into these areas. The surfaces should be wiped dry before new oil is added to the engine.

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Air Intake & Exhaust Systems

introduction In this chapter we will .Jok at the two types of air intake systems, roots blowers, and turbochargers, with their related exhaust components.

Turbochargers The turbocharger assembly, Fig. 7-1, is primarily used to increase engine horsepower and provide better fuel economy through the utilization of exhaust gases. As shown in cross-section, the turbocharger has a single stage turbine with a connecting gear train. The connecting gear train is necessary for engine starting, light load operation, and rapid acceleration. Under these conditions, there is insufficient exhaust heat energy to drive the turbine fast enough to supply the necessary air for combustion, and the engine is actually driving the turbocharger through the gear train assisted by exhaust gas energy. . p>v

When the engine approaches full load, the heat energy in the exhaust, which reaches temperatures approaching 1000°F (538OC),is sufficient to drive the turbocharger without any help from the engine. At this point, an overrunning clutch in the drive train disengages and the turbocharger drive is mechanically disconnected from the engine gear train.

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COMPONENT FAMILIARIZATION The next section is designed for familiarization with the major turbocharger components. These include the doweling assembly, the turbine wheel, the geardrive assembly, etc. Minor pa& such as hardware, brackets, etc. will not be covered unless these items perform some special function.

Figure 7-1 Turbocharger

Turbocharger Nameplate

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Figure 7-2 Turbocharger Nameplate

Part Number .

The part number specifies exactly what model the turbo is; i.e., 16 cylinder marine turbo, etc. An EMD parts catalog such as #300 will provide a turbo application list on Parts List #174. This chart will indicate specifically what turbo is required on each engine.

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Serial Number

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The serial number indicates the date, production sequence number, and assembly location of the turbo. For example:

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Year (1988)

Month * (Jan)

Type * (New)

Plant * (LaGrange)

Sequence * (#5)

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A = January, B = February, etc. The letter “I” is not used, so a December built turbo carries an “M” designation.

* Type:

A “1 ” indicates a new unit. A “2” indicates a repaired and returned machine. A “3” indicates a Unit Exchange (UTEX) turbo.

* Plant:

There are three plants involved in the assembly of turbochargers. 1 = LaGrange, 11. 5 = Halethorp, Md. 6 = Commerce, Ca.

* Sequence:

The last three digits of the serial number indicate the sequence number of turbos built at a specific plant each month. The “005” in the example indicates that the turbo was the 5th one built at the LaGrange plant during the month of January, 1988.

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Identification Code

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The identification code indicates the turbo model, gear ratio, and most recent significant change or revision from the original design which was in effect at the time that the turbo was assembled. For example:

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Model

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Ratio

R Revision

Model:

E = 645 Engine Turbo; T = 567 Engines; G = 710 Engines

Ratio:

The gear ratio of the turbo with respect to engine crankshaft speed. An 18 indicates that the turbo runs at 18 times the crankshaft speed. 16.8:l and 17.9:l are also common gear ratios.

Revision:

There have been several revisions or improvements incorporated into the turbo since its inception. The letter code designates the latest revision which was applied to the turbo.

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Doweling Assembly The doweling assembly forms the backbone or casing for all the turbo’s internal components. The assembly is comprised of 6 iron castings, which are aligned to one another by dowels and held together by various threaded fasteners. The alignment of these parts is critical, and the bore through which the turbine wheel passes is held to a maximum of .0005 t.i.r. Consequently, during manufacture, the six pieces are aligned and then doweled to maintain that alignment. Next, they receive stamped “doweling numbers” which identify them as a matched set. In the event that one of these components becomes damaged during the life of the turbo, a new part must be aligned to the remaining set components. This new part will then receive a matching doweling number to identify it as part of the original set.

Figure 7-3 Turbocharger Doweling Assembly

The doweling assembly is comprised of the following: 1. COmpressor Scroll - Forms the scroll through which compressor air flows from the turbine wheel to the engine.

2. Compressor Bearing Support - Provides a location point for the turbine wheel compressor-end support bearing. (Also forms the rear half of the air scroll.)

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- The central component to which the others attach.

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connect the rotating assembly to the engine gear train.

6. Carrier Bearing Support - Provides a location for the roller bearing which is used to support the planetary gear carrier shaft.

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Main Housing “Cradle”Gasket Area The gasketed surface between the main housing and compressor bearing support (which is known as the “cradle”) was changed from its original 3-piece conventional gasket design to incorporate improved sealing technology. The area which requires sealing is an oval-shaped oil drainage passage at the. bottom of the “cradle”. The original configuration utilized a paper-type gasket at the bottom one-third of the cradle sealing the opening. O n each side of the paper gasket was another made of metal shim stock. These 2 metal gaskets were not required for sealing purposes, but rather were necessary in that their thickness matched the compressed paper gasket thickness. Consequently, the metal gaskets served to maintain parallelism between the two doweling components when the paper gasket was installed. Due to the unfavorable environment in which the cradle gasket was located (heat and vibration), a more durable seal was desired. In the late 1970’s a revised sealing arrangement was released. The turbo main housing oil drain hole was changed from an oval shape to a double round hole configuration with counterbores for O-rings. The 0ring type turbos required no gaskets between the main housing and compressor bearing support. In order to improve the seal on older castings which were made with oval-shaped openings, a new seal was developed. This seal, known as the “Parker Seal”, is equipped with an oval-shaped O-ring on each side of a metal plate. The seal is retained by two of the doweling assembly through bolts. These improved seals can be applied to most turbos utilizing the oval oil drain configuration by simply machining a relief in the cradle flange of the turbo main housing during overhaul.

Figure 7-4 Original 3-Piece Cradle Gasket (Model Code Designations Prior to “R”)

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Figure 7-5 Parker Seal (,” Model Code Designations)

Electro-Motive Model 567,645 & 710 Serles Diesel Engines

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Turbine Wheel The turbine wheel or rotating assembly as it is sometimes called, is the heart of any turbocharger. It is comprised of a shaft, on which both the turbine blades (exhaust fan) and the impeller (air compressor fan) are located. The shaft is supported near each end by 2 support bearings. The bearing nearest the impeller is called the compressor bearing, and the one nearest the turbine blades is known as the turbine bearing. O n the EMD turbo, a small gear is located on the extreme end of the shaft near the turbine blades. This gear, in conjunction with a series of others, provides the connection of the turbine wheel to the engine crankshaft as previously discussed. T h e balance of the rotating assembly is extreme+ critical in order to ensure that vibrations which might occur at the high rotational speeds are minimized. Beginning at the impeller-end, the components of the rotating assembly are as follows: 1. Impeller Retaining Nut

- Plastic insert type.

2. Retaining Washer - Secures impeller on shaft. 3. Compressor Impeller - An aluminum castings (forging on 710 model) which contains the blades used to pump air. Blade quantities:

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Figure 7-7 lmpeller Design Comparisons

4. Impeller Spacer - A machined washer which acts as a portion of one of the 3 air seals along the rotating assembly shaft.

- The finished surface on the compressor portion of the shaft which corresponds to the compressor bearing.

5. Compressor Bearing Journal

6. Heat-Dam Washer - A large washerldisc featuring lands on the surface which contact the turbine wheel to minimize metal to metal contact, thus reducing heat transfer from the turbine wheel to the bearing surface. 7. Compressor Seal - A machined surface on the turbine wheel which acts as a portion of the‘second air seal along the rotating assembly shaft.

8. Turbine Wheel - The central hub of the rotating assembly, on which all the turbine blades are located. 9. Turbine Blades - The blades which collect the exhaust gas flow and cause the rotating assembly to turn. Numbers of blades: 567 & 645 All Models 710-B Models

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Sun Gear Shaft - The rotating assembly shaft is actually split into two parts. The turbine wheel forms the “front” end, containing the impeller and turbine blades, while the sun gear shaft forms the “rear” end. The sun gear shaft comprises 3 distinct components. a. Turbine Seal: A machined surface on the shaft which acts as a portion of the third air seal along the rotating assembly shaft. b. Turbine Bearing Journal: The finished surface on the turbineend of the shaft which corresponds to the turbine bearing. c. Sun Gear: A gear which is a part of the sun gear shaft, and acts as the central gear in the planetary geardrive system.

7-8

ElectrMotive Model 567, 645 & 710 Series Diesel Engines

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Turbocharger Bearings As previously discussed, the rotating assembly is supported by two bearings which are located in the doweling assembly. Due to the high speeds and temperature levels that the turbine wheel is exposed to, the design and construction of these bearings is rather unusual. Both the compressor journal bearing and the turbine journal bearing are designed with cylindrical tapers which form oil wedges that develop powerful radially oriented hydraulic forces to center the rotating journals. Thus, rather than using a concentric bore on the inside diameter of the bearings, oil “ramps” are utilized. The hydraulic forces developed in the journal bearings and thrust bearing far exceed the engine lube oil pressure. Also, because these forces are generated by the rotating journals, the hydraulic forces increase as rotor speed increases. There may be 3,4, or 5 ramps on the inner surface of the rotating assembly support bearings. Each ramp begins at an oil “channel” or groove. The distance from the surface of the bearing to the journal is greatest at this point. As the ramp extends around the inside of the bearing, its height increases and the clearance between the bearing and the journal decreases. The difference in ramp “height” from the low-end at the oil channel and the high-end is approximately .003-,004”. The lubricating oil which is pumped into the bearings is drawn along the oil ramps by the rotation of the turbine wheel. As this oil flows along the ramp, the bearing clearance decreases, which increases the centering force exerted on the journal. This is known as a “hydra-dynamic” bearing design.

1.

Compressor Bearing: The hydra-dynamic bearing through which passes the impeller-end of the rotating assembly. The compressor bearing supports the compressor portion of the rotating assembly shaft. The inboard end of the compressor bearing is flared and manufactured with a convex surface to form a part of the thrust bearing assembly. The compressor bearing is located in the compressor bearing support, and is retained by an interference fit.

2.

Thrust Bearing: A disc-shaped bearing through which the turbine wheel shaft also passes. One side is concave to correspond with the flared end on the compressor bearing. These curved surfaces permit a self-aligning feature. The opposite side of the thrust bearing appears flat, but actually consists of a series of tapered pads on the thrust face which form oil wedges that develop hydraulic pressure to separate the bearing from the rotating heat dam thrust washer. 6

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The thrust forces found in the rotating assembly are caused by the pitch of the impeller blades. These blades are shaped to pull air through, similarly to the propeller on an airplane. Unlike the airplane, which uses this concept to pull the machine through the air, a turbocharger impeller must remain stationary to pump the air through its compressor section.

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It is the function of the thrust bearing to control the tendency of the turbine wheel to move forward. Exhaust pressure against the wheel also contributes to the load the thrust bearing must control. The thrust bearing is located between the flared edge of the compressor bearing and the heat dam washer on the turbine wheel.

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Turbine Bearing: This bearing supports the 2un gear end of the rotating assembly. Its construction is similar to that of the compressor bearing, except that it does not have the flared edge. The turbine bearing is located in the “clutch support”, which in turn is located in the turbine bearing support.

4.

Planet Gear Bearings: A set consisting of three identical bearings, one for each of the 3 planetary gears. These bearings differ from those previously discussed in that the oil ramp is on the outside diameter of the bearing. One bearing is installed in the bore of each planet gear, and the gears rotate on the stational? bearings.

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TURBINE BEARING

Turbocharger Labyrinth SeaIs The seals usedin the turbo utilize air pressure as the a c b d seal. No physical contact between the turbine wheel shaft and the seal occurs. Instead, pressurized air from the compressor scroll is ported to three “labyrinth” seals through a “bleed” air duct. Once in the seals, the air emits from a small hole in the bore through the center of the seal. This bore, through which the rotating assembly passes, contains several grooves or “labyrinths”.The air flows around the seal in these grooves, effectively sealing the area.

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ITS Locomotive Training Series Student Text I l r .

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Figure 7-1 1 Turbocharger Bearings 6.Labyrinth Seals

These seals are effective at separating the lubricating oil from the exhaust gases. However, improperly filtered air can form dirt deposits within the air passages, which will restrict the air flow and reduce the effectiveness of the seals. There are 3 labyrinth seals in the EMD turbo. 1. Impeller Seal: Located directly behind the impeller, this seal prevents oil in the compressor bearing area from being drawn out into the compressor air scroll by the suction created as the impeller spins.

2. Compressor Seal: This seal is located between the turbine blades and the compressor bearing. Its function is to prevent oil from migrating into the exhaust section from the compressor bearing.

3. Turbine Seal: The turbine seal is located between the turbine blades and the turbine bearing. It prevents oil from migrating into the exhaust duct from the turbine bearing.

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Turbine Inlet Scroll The high-energy exhaust gas is deliverecl to the single-stage turbine by the exhaust inlet scroll. This component is a welded assembly made from “chromemoly” plate which is formed so that the incoming gas flow is smoothly and evenly distributed with a minimum of turbulence.

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Figure 7-13 Turbine Inlet Scroll 6 Nozzle Ring

Nozzle Ring The nozzle ring is located in the exhaust portion or turbine section of the machine. The nozzle ring consists of a series of stationary vanes through which the exhaust gas from the engine must pass in order to reach the turbine blades. Each passage between the vanes is called a nozzle. The nozzle ring is therefore simply a ring of individual nozzles which are mounted on a common ring. The gas is throttled and directed by the nozzles into the turbine wheel blades. The size of the nozzle openings must be matched to the amount of exhaust gas generated by the particular engine that the turbo is designed for. Larger passages are found on nozzle rings for larger engines, etc. This is due to the fact that larger engines flow a higher exhaust gas volume than do small ones. Consequently, a small nozzle ring would choke a large engine’s exhaust gas flow. Conversely, a large nozzle on a small engine would not provide enough restriction for the gas flow to develop the correct amount of velocity as it flows through the passages. rd.

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The principle may be more easily understood if compared to a garden hose nozzle. As the nozzle opening is decreased more energy or force is obtained from the flow of the water. In the turbocharger, the optimum nozzle opening is just enough to allow an engine’s maximum exhaust gas volume to pass without creating a back-pressure. If the gas cannot flow through the nozzle quickly enough, it will begin to “back-up” in the exhaust system and the turbo will eventual1 “sur e”. The term surge refers to a reversal of the gas flow through the turbo. The mac ine actually “burps” exhaust back through the engine due to a greater pressure within the engine or exhaust system than that of the incoming air supply.

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Turbine Shroud and Retaining Clamp The turbine shroud is a metal band which encircles the turbine blades. Because the turbo’s power is generated by the exhaust gas between the blades, high efficiency is obtained by minimizing leakage around the blades. Consequently the turbine shroud is formed around the blade tips on the turbine wheel. The shroud’s function is to ensure that the exhaust gas flow across the turbine blades is maximized by reducing gas leakage around the blade tips. The blade tip to shroud clearance must be small enough to minimize gas leakage, but large enough to prevent contact with the blade tips as they enlarge through thermal growth. For this reason, the inside diameter of the EMD turbine shroud is Figure 7-14 Turbine Nozzle Ring sprayed with a “soft metal” abrasable coating. The blades can actually establish their own path in this coating as their temperatures normalize, creating a custom-fitting shroud for each individual turbo. The shroud is retained (in most turbo models) by a clamping ring known as the “Marmon Clamp”. This clamp consists of a metal band, to which 4 channel segments are spot-welded. The channels engage a flange on the edge of the turbine shroud, securing it within the turbo. A “T-bolt” and nut are used to apply clamping load to .the assembly. An improvement was made to the Marmon clamp in the early 1980’s. Prior to this improvement, the strap to which the T-bolt is attached was spot welded to the clamp. Tests in the field indicated that the clamp could suffer from metal fatigue in the area adjacent to these welds after repeated thermal cycling. An improved clamp was released which utilizes rivets to secure the T-bolt strap. This clamp has proven more durable in severe service applications.

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Exhaust Diffuser The exhaust diffuser is another aerodynamic device located in the turbine section of the turbo. The diffuser is basically an arrangement of 3 or 4 vanes (stationaryfins) which are placed directly behind the turbine blades. As the exhaust gas flows through the turbine blades, it next must enter the turbo’s exhaust duct. In order to direct this flow of gas from the blades smoothly into the duct, the diffuser vanes provide a smooth transition path for the gas to follow, thereby eliminating turbulence.

Exhaust Duct

Figure 7-16 Turbine Shroud Retainer, Exhaust D u d and Exhaust Difiser

The exhaust duct acts as the outlet for the engine’s exhaust gas after it has passed through the turbine blades. The duct “floats” to allow for thermal expansion and is mounted with bolted spring washers located along a mounting “foot” on each side where it rests on the main housing. The duct is sealed to the turbo by means of a half-lap joint and retainer ring on the compressor bearing support side and two spring-tensioned seal rings at the inlet scroll end. There are two basic exhaust ducts which are applied to the EMD turbo, The “standard” duct is attached to the turbo main housing by 3 spring washer sets on each mounting foot. This duct was used on most applications until the late 1970’s.The other basic duct, known as the “big-foot” duct, is two inches shorter than the standard duct, and is attached to the turbo by 5 spring washer sets on each mounting foot. This duct was designed for the application of an exhaust silencer atop the turbo duct, and is therefore made shorter and is heavily reinforced to support the added weight.

A built-in aspirator tube provision in both ducts allows for the installation of an “eductor tube”, which produces a suction that is applied to the engine crankcase for ventilation. As exhaust gas flows upward and out of the duct, a negative pressure is established behind the beveled end of the tube. The outboard, flanged end of the tube is connected tewarfidter which contains a screen called the lube oil separator. The suction applied above the screen in the separator draws vapors from the engine crankcase, while the screen prevents lube oil from being drawn out. Locomotive applications which utilize an exhaust silencer, as well as most marine and industrial applications, use an “ejector‘ arrangement. This system uses compressor discharge air directed through a venturi and combined with the eductor tube suction to aspirate the crankcases of these engines which have inhibited exhaust gas flow due to restrictions such as silencers or long runs of exhaust ductwork. 7-16

ElectroMotive Model 567.645 81710 Series Diesel Engines

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A drain opening is provided near the bottom of the duct to allow for the drainage of rdinwater which may enter the duct while the engine is shut-down. This drain hole location corresponds with a small tube that passes through the compressor bearing support from the impeller side. The drain hole is of a larger diameter than that of the tube. When the impeller is spinning, pressurized air is blown through the tube, and into the duct drain. This pressure, being greater than the exhaust gas pressure in the duct, effectively prohibits gas leakage through the drain. However, when the impeller is not in operation, no air pressure flows through the tube. In this case, the drain hole in the duct will allow any fluids which have collected in the exhaust duct to drain into the turbo main housing, which has a corresponding hole near the bottom for further drainage out of the entire turbo.

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COMPRESSOR DIFFUSER The compressor diffuser consists of a row of fins or (‘vanes’’which are attached to a mounting ring and positioned around the circumference of the impeller. The vanes direct the flow of compressed air which is discharged from the impeller and provide a smooth air delivery which is free of turbulence. The compressor diffusers are manufactured with specifically sized “throat passages” between the vanes. The size of these passages controls the air flow so that the compressor power requirements are balanced with the power generated in the turbine by the exhaust gas energy at full load. For this reason, the compressor diffuser throat area must be “matched” to the turbine nozzle ring area during turbo assembly.

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These throat passage sizes also correspond to the volume of air that the turbo supplies. For example, a turbo for a 16 cylinder engine contains a diffuser with larger throat passages than one designed for use on a 12 cylinder application.

Figure 7-18 Compressor Diffusers

Figure 7-19 Compressor Diffusers

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Electrdvlotive Model 567,645 81710 Series Diesel Engines

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PLANET GEARS

G The sun gear which is machined onto the end of the turbine wheel meshes with

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3 planet gears. These gears engage with the sun gear at 120 degrees intervals, and are

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located by a planetary gear carrier shaft. The carrier shaft is basically a disc, from the face of which extends 3 pins. Each pin passes through the center of a planet gear. O n the opposite side of this disc, the carrier shaft itself is splined.

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There are two basic planet gear designs: the original or “standard” 32 tooth gear and the “high-capacity” 47 tooth gear. It is a fact that all gears transmit a vibration as their teeth mesh. The level of vibration varies with such things as wear, roughness, and tooth profile. The original configuration planet gear set performed satisfactorily in the rail applications for which it was designed, but when EMD turbocharged engines began to see service in high gear-loading applications such as generating set installations, a more durable gear design was desired. Generating sets, for example, are subjected to constant high rpm regardless of the amount of load on the system. This constant speed is necessary in order to maintain the electrical “line frequency”. Such engines often run at less than full rated load. Consequently, exhaust gas energy levels are lower than normal, which means that the turbo gear drive must make-up for the less powerful exhaust. The end result of continued operation in this mode is accelerated planet gear wear. Worn planet gears can cause seriously increased gear vibration levels. The increased vibrations in the planet system cause the turbine wheel to vibrate. This vibratory input results in turbine blade fatigue fractures in worst-case situations, and rapid clutch wear in many cases. The solution to the problem is to reduce the vibration level generated by the gear mesh by increasing the tooth to distribute loading over a larger area. These “high-contact” or “high capacity” gears significantly reduced the light-load vibratory levels, and tooth wear was nearly eliminated under high gear train loading conditions. Usage of the high-capacity gear train has spread over the years from marine drilling applications only to marine propulsion, industrial generator sets, and rail engines as well. Turbos utilizing the standard gear design carry 18:l or 19.7:l gear ratio designations.Those which contain the high-capacity gears utilize ratios of 16.7,16.8,or 17.9:l. In any case the ratio designation refers to the speed differential between the turbocharger impeller and the engine crankshaft.

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RING GEAR AND CLUTCH HOUSING The third element in the planetary gear tralli is the ring gear. The ring gear surrounds the 3 planet gears, and is manufactured with internally cut teeth on the inside diameter. Consequently, each planet gear’s teeth are actually engaged to 2 gears simultaneously:

1) 2)

the sun gear on the turbine wheel shaft the ring gear which surrounds them.

T h e ring gear is attached to a housing which encases the turbo clutch. The means of this attachment are bolts, so the ring gear is locked to the clutch housing. This clutch housing is located within the turbine bearing support (part of the doweling assembly), and rotates on the outside diameter or the clutch support (where the turbine bearing is located). Bronze thrust washers and bushings are used as bearing surfaces between the clutch support and the clutch housing.

Figure 7-20 Ring Gear and Clutch Housing

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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CLUTCH CAMPLATE AND ROLLERS The overrunning clutch design allows rotation in one direction, and engagement or “lock-up” in the other. This is accomplished through the use of a center hub called the support, a set of cylindrical rollers, and a surrounding ring called the camplate, which utilizes a series of wedge-shaped pockets in which the rollers are located. The 12 pockets in the camplate are designed with an angled ramp in each. Thus, the distance from the outside diameter of the support to the ramp varies depending on where the measurement is taken. This pocket depth at one end of the ramp is greater than the diameter of the roller. However, at the opposite end of the ramp, the pocket depth is less than the roller’s diameter. Consequently, when the roller approaches this end, it becomes wedged between the support and the camplate ramp, locking the two parts.

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On the example below, note that if the camplate were rotated in a clockwise direction, the rollers would move into the large ends of the camplate ramps, allowing the camplate to rotate free of the support. However, if the camplate were turned counterclockwise, the rollers would travel to the small ends of the ramps and effectively lock the camplate to the stationary clutch support. The camplate is located in the clutch housing, on the end of which is also found the ring gear. The camplate is attached to the clutch housing by means of 6 “drive pins” or dowels. As a result, the camplate and ring gear operate as one unit, each one being attached to the clutch housing at opposite ends. Since the clutch support is stationary in’the turbo (being bolted to the turbine bearing support), when the camplate locks to the support, the clutch housing and ring gear also become locked.

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GEAR DRIVE SYSTEM The splined-end of the carrier shaft extends through the idler gear support, which is the plate at the back of the turbo. Two bearings are used to support the carrier shaft: 1) a ball bearing located in the idler gear support; and, 2) a roller bearing which is in the carrier bearing support.

O n the splines of the shaft, a carrier drive gear is mounted. This gear is actually externally mounted on the turbo, although most of it is obscured from view by the carrier bearing support. Located on a small stub-shaft attached to the idler gear support below the carrier gear is the turbo idler gear. The idler gear is engaged with the carrier drive gear at the top, and with the engine’s gear train at the bottom. The idler gear is mounted on a special, barrel-faced roller bearing. This bearing has a self-aligning feature due to the barrel-shaped rollers. As a result, the gear can actually be “wob bled” on its stubshaft if force is applied.

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: Carriar Shaft Spacer 2. Set Of 3 Matched Planet Gears 3. Planet Gear Shafts 4. Planet Gear Bearings 5. Carrier Shaft 6. Carrier Shaft Ball Bearin 7. Idler Gear #upport 8. Idler Geer

9. Idler Gear Roller Bearing 10. Idler Shaft 11. Carrier Drive Gear 12. Carrier Shaft Retainer Plate 13. Carrier Gear Roller Bearing 14. Lube Oil Jumper

Assepbly 16. Carrier Bearing Support

Figure 7-23 Gear Drive Section

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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GEAR-DRIVE SYSTEM Right-Hand Drive Applications: Some marine propulsion applications of EMD engines employ two counterrotating engines. In such installations, a pair of engines, one left-hand rotating (standard) and one right-hand rotating share a common hull. Since the gear train of the right-hand rotation engine turns in the opposite direction from that of the standard engine, a special turbocharger is required. The turbo for use on these right-hand rotation engines utilizes two turbo idler gears rather than the single gear on more common models. In this way, even though the engine gears turn in the opposite rotation, the turbine wheel is driven in the same direction on all EMD turbochargers.

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LEFT HAND ROTATION GEAR TRAIN

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Figure 7-24 Gear Drive Systems

LUBE OIL SYSTEM The turbocharger’s lubrication system is actually an extension of the engine oil system. Following is a description of flow: 1. As oil travels through the main oil gallery in the crankcase towards the rear of the engine, it enters the stubshaft bracket assembly on the end sheet of the engine.

2. An oil passage or groove in this bracket directs the oil to an oil manifold which is also attached to the end-sheet. The oil flows through the manifold and is delivered to the turbo oil filter mounted on the engine. 3.

Oil flows through this filter, which carries the same rating as the filters in the main filter tank.

4. Provided the filter is not plugged, oil leaves the filter and flows back through the lower leg of the oil manifold. Note: If the filter is plugged, no oil will flow through the small oil pressure sensing line which connects the engine governor to the downstream side of the turbo filter. 5.

Oil flows through another grooved passage in the engine stubshaft bracket and is admitted to the upper idler stub.

ITS Locomotive Training Series - Student Text

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6. Oil flows through a passage in the center of the stubshaft into the 4inch bore in the turbo main housing.

7 . A vertical passage in the turbo main housing called the “main oil supply” directs the oil upwards.

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8. The main oil passage emits oil at the top for the clutch and planetary gears. A branch line from the main passage passes through the main housing carrying oil to the auxiliary generator drive and also intercon nects to the compressor and turbine bearing lines.

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SOAK-BACK SYSTEM Due to the fact that the turbo is dependent upon the engine main oil system, an additional lubrication system is required to protect the turbo during those periods when main oil system flow is unavailable.

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The main oil system is driven by a gear train connected to the crankshaft. Consequently, oil flow is present only when the crankshaft turns. During an engine shutdown, the crankshaft continues to turn for 5-10 seconds after the shutdown is triggered. However, due to the high speed at which the turbine wheel operates, the momentum of the mass causes the turbine to “run down” for periods as long as 3540 seconds. Consequently, no lubrication is provided to the turbo’s bearings by the main oil system during this time.

As a result, an electrically-driven oil pump called the “soakback Pump’’ is mounted on the engine to provide lubrication to the turbo during this rundown period. As the engine shutdown cycle occurs, the pump is energized and begins to supply the turbo with oil. After the engine stops, the soak-back pump continues to . heat operate for 30-35 minutes. During this time, the flow of lube oil is used to carry from the turbo’s seals and bearings(hence the name “soakback"). The soakback pump is also energized during the engine start sequence. In this instance, the bearings in the turbo are supplied with oil even before the oil flow from the main system can reach them. In this way the soakback pump serves to prelubricate the bearings.

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EiectroMotive Model 567,645 & 710 Series Diesel Engines

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Figure 7-25 Turbo Lube Oil System

PLANETARY SYSTEM OIL DRAINAGE SCREEN Lube oil drainage from the planetary system of the turbo passes through openings in the idler gear support. In the event of a planetary system failure, metal fragments and broken gear teeth may be carried-off with oil drainage. To prevent these metal fragments from entering the engine oil sump or passing through the diesel engine's rear gear train, a screen is installed in the idler gear support. The original screen was located in a small triangular-shaped opening in the idler gear support. Most planetary system drain oil flows through this area. However, turbos which are equipped with the highcapacity type planet gears have a higher oil flow rate which requires an increased oil drainage provision. The idler gear support on such turbos utilizes three slotted passages on the face of the support in addition to the triangular opening. Drain oil flows through all four of these passages. Consequently, it is necessary to provide increased protection in the way of a larger screen.

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In the mid-l980's, an improved screen was released for retrofit in the high-capacity turbos. The screen is installed on the inboard side of the idler gear support, and oil must pass through it as it flows through any of the four possible drainage paths. Turbos so-equipped do not utilize the previous triangular screen.

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GEAR TRAIN OPERATION The EMD turbocharger utilizes a geardrive system which takes energy from the engine’s crankshaft and transmits it to the turbine wheel at the sun gear. This planetary gear drive system is used when exhaust gas energy levels are not sufficient to drive the turbine wheel, such as during engine starting and low speedflight load periods of operation. Dependency on the gear drive system decreases as exhaust energy levels increase, until eventually no mechanical assist is required. It is the function of the overrunning clutch to “disengage”the gear drive. This is accomplished by allowing the rotating assembly to overspeed the driving gear train while the gears remain engaged. This power take-off originates at the upper idler gear in the engine’s camshaft drive gear train. This upper idler gear is equipped with a shock damping device which uses packs of coil springs to absorb torsion shocks in the engine’s gear train. Attached to this damping device is a turbo drive gear. The turbo drive gear, which serves as the power take-off for the turbo’s gear train, is isolated from the inherent engine torsional vibrations which can be detrimental to the turbo’s longevity. Figure 7-26 Spring Drive Gear The next gear in the turbo gear train is mounted on the “rear” of the turbo at the idler gear support. This gear is appr0priate.j named the turbo idler gear. The idler gear drives a turbo-mounted carrier shaft drive gear. This gear is located on the end of the planetary gear carrier shaft. The carrier shaft extends through the rear “bulkhead” of the turbo and carries the 3 planetary gears.

The planet gears are engaged to both the sun gear on the end of the turbine wheel, and to a ring gear. The 3 planet gears surround the central sun gear, Obeing meshed with the sun at 120 degree intervals. These planet gears are also surrounded by a ring gear. The ring gear is manufactured with internal teeth, so that a “track” is formed on which the 3 planet gears can travel. The ring gear is attached to the clutch camplate, and the two components operate together as one. If the camplate rotates, so does the ring gear. Conversely, if the camplate is locked, the ring gear cannot move. .

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To understand how the engine gear train drives the turbine wheel, a simulated engine start-up sequence follows:

1. As the starter motor pinions engage the flywheel, the crankshaft is rotated

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Electro-MotiveModel 567,645 & 710 Serbs Diesel Engines

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2. The lower idler gear in the camshaft gear train is turned by the force transmitted from the gear teeth on the crank gear to those on the lower idler.

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3. The lower idler gear teeth transmit force to the upper idler gear teeth which they engage with, turning the upper idlerhpring-drive gear ass embly.

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The turbo drive gear (on the spring-drive gear) assembly transmits force to the teeth of the turbo idler gear.

5 . The turbo idler gear teeth turn the carrier shaft drive gear.

6. The carrier drive gear turns the entire carrier shaft assembly. 7 . The 3 planet gears located in the rotating carrier shaft pass the torque on to both the sun gear and the ring gear.

8. The torque input to the ring gear turns it (and the clutch housing) in the opposite direction. However, after a very short travel the camplate locks to the clutch support due to the rollers which have become wedged in the ramps. 9. With the ring gear held stationary, gear train torque is transmitted through the planet gears to the sun gear. This causes the sun gear to drive the turbine wheel (in a counterclockwise direction as viewed from the impeller). Due to the speed-increasing nature of a planetary gear system, the sun gear’s rotational speed is significantly higher than that of the carrier shaft assembly which drives it.

10. As the impeller is rotated, air drawn through the engine filters increases in velocity while passing through the compressor di&ser and air scroll with a minimum of turbulence. The size of the passages in the compres sor d i h s e r controls the air flow so that the compressor power require ments are balanced with the power generated in the turbine by exhaust gas energy at full rated load. (It is for this reason that the compressor diffuser throat area must be “matched” to the turbine nozzle area when the turbo is assembled.)’

11. As air is pumped into the engine, the combustion process begins. As the engine runs, the exhaust gases from the individual cylinders are directed through the turbine section of the turbocharger. The energy extracted from these gases is applied to the turbine blades, and this force aids the engine gear train in turning the rotating assembly.

12. Two sources of torque are fed into the planetary gear system. The torque developed by the turbine is fed through the sun gear, and the torque transmitted by the gear train is fed through the carrier shaft to the planet gears. Thus, the torque transmitted to the ring gear is the difference between the levels of the two torque inputs. ITS Locomotive Training Series - Student Text

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13. When the turbine does not develop sufficient power to turn the rotor at the enginedetermined driving speed, the torque input through the planet gears continues to hold the ring gear and camplate in the “locked”direction as previously described. However, when the power developed in the turbine is capable of driving the rotor faster than the speed dictated by the turbo gear ratio, the increased torque from the sun gear is fed through the planet gears to rotate the ring gear and camplate in the “unlocked”direction. The clutch housing now rotates around the clutch support at a speed and turbine wheel RPM.During this overrunning condition, the clutch rollers are in the wide end of the wedge-shaped pockets formed by the camplate ramps.

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14. The turbo continues to operate in this “free-wheeling” state so long as the exhaust gas energy level and flow rate are sufficient to provide enough power to drive the rotating assembly faster than the gear train would. However, if the engine speed or load is reduced, the amount of energy in the exhaust decreases, and the turbine speed begins to drop. When the turbine speed returns to that of the gear train, the clutch reengages and the gear train once again provides a portion of the energy requirement to drive the rotating assembly.

TURBOCHARGERS WITH EXTERNAL CLUTCH All 567-T and most 645-E/F turbos utilize the internally located 12 roller clutch design as discussed. However, in the early 1980’s an experimental “external clutch” was field tested in selected applications where loads on the conventional clutch were severe. These tests were conducted with 645 turbos primarily in marine towing service. The external clutch became “basic” or standard equipment with the 710-G engine. This design removes the clutch from within the turbo and places it in the engine camshaft drive gear train instead. The spring-drive gear assembly found in the previous 6 4 5 series is replaced with a new double gear assembly which is interconnected by means of a large version of the roller clutch configuration. The clutch utilizes 16 three-quarter inch diameter rollers in place of the 12 one-half inch diameter rollers found in the internal clutch. The new rollers are one and one-half inches long, whereby the 12 roller clutch used one inch long rollers. Correspondingly, the camplate diameter of the external clutch is approximately 11.750” compared to the 7.750” of the previous type. Also, the camplate roller pockets are inverted, or open towards the outside diameter rather than toward the center of the p+$ q OE previous versions. The increased size of these components, coupled with the more numerous rollers, has improved the load-carrying characteristics of the roller clutch tremendously.

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ElectrMotive Model 567,645 & 710 Series Diesel Engines

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The principle of operation is exactly the same as that of the internal clutch. However, since the clutch disengagement takes place in the engine gear train, the turbo’s planetary ring gear is now “locked” in a stationary position. This lock-up device occupies the space where the roller clutch had been on previous turbo models. The clutch support has been modified from its original configuration with the addition of a row of gear teeth. The outside diameter of these teeth is the same as that of the three planet gears in the carrier shaft assembly. The ring gear is now much longer than its predecessor, with two rows of identical teeth cut on the inside diameter. This new ring gear bears a resemblance to a sleeve such as is used to synchronize gears in automobile transmissions. The clutch support teeth enter the ring gear at one end, and the planet gears from the other. Since the clutch support is fixed in place, its tooth engagement with the ring gear prevents rotation of the ring gear. Although not a common practice, the external clutch can be applied to 645 type turbos equipped with high-capacity planetary systems.

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Figure 7-27 External Clutch

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EXTERNAL INSPECTION AND OPERATIONAL PROBLEM DIAGNOSIS Over the past several years, many items have been written and discussed regarding how to qualify an EMD turbocharger for continued service when a problem has been reported. Many of these techniques have been passed on verbally, while others were written procedures foun‘d in Engine Manuals, Troubleshooting Guides, or various written correspondence. In some cases, these procedures have become obsolete or in need of revision due to the evolution of the turbo, as well as a broader base of practical experience from which to draw on. The following pages are offered to assist EMD customers in troubleshooting and requalifying their turbos.

CHECKS WHICH CAN BE MADE WHILE THE TURBO IS STILL ON THE ENGINE

A.

ROLLER CLUTCH TEST

1.

Idle engine until normal operating temperature is reached. (If engine cannot be started, remove rubber boot from turbo inlet and verify that the impeller locksup when attempting to turn in a clockwise direction by hand. If this does not occur, either the clutch has completely failed or a planetary gear train failure has occurred. Refer to paragraph Additional External Inspections.)

2.

With engine warmed-up, push injector control linkage lever inward, increasing engine speed to approximately 700 RPM.

3.

Pull injector control linkage lever out completely to “No Fuel” position, overriding the engine governor. (At this time, the clutch will disengage, allowing the turbine to spin free of the gear drive.)

4.

As the engine begins to stall, push the injector linkage lever in once again, providing more fuel, which should increase engine speed. The decelerating turbine wheel will “meet” the accelerating eqgine gear train and the roller clutch should engage, providing sufficient air for continued engine speed increase.

If the clutch fails to engage, the injector rack linkage will move toward “full fuel” position, black smoke will emit from the exhaust duct due to a lack of air, and the engine may stall. These symptoms indicate an imminent clutch failure, consequently the turbocharger should be replaced. Turbocharger roller-type clutches tend to h i €gradually rather than suddenly.

This characteristic refers to the fact that in early stages of clutch wear-out, the slippage may be intermittent. In such instances, the engine may smoke heavily or stall during speed changes, yet behave normally later. T o ensure that the clutch is not in this early stage of failure, the aforementioned test procedure may be repeated a few times. However, articles stating that as many as 30 consecutive tests may be required are in error.

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ElectroMotive Model 567, 645 & 710 Series Diesel Engines

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To avoid damaging a good clutch, injector linkage manipulation should not be performed more than 2 or 3 times to qualify a clutch. If the clutch is in fact defective, the turbo should exhibit the reference symptoms within this number of trials.

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Since 1976, virtually all regular production 567 and 645 EMD turbos have been built with a roller-type clutch. Prior to that date, some turbos had utilized a ratchet-type clutch/friction drive gear configuration which required a special requalification procedure using a torque wrench. Under no circumstances should a wrench be applied to the compressor impeller nut to determine roller clutch condition. A test of the older design friction drive gear called for the application of a torque wrench to the impeller nut. The observed “break-away torque” provided an indication of the condition of the friction drive gear, but no conclusion could be drawn as to the turbocharger clutch condition from this test. Furthermore, this test was valid only on turbos equipped with the previous “ratchet” clutch. Engines equipped with roller clutch turbos should not be subjected to this procedure.

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TURBOCHARGER OIL PRESSURE TEST

In some instances, it may be prudent to confirm that the main engine and soi--back oil systems are actually delivering lube oil to the turbo. This test would -e recommended after the installation of a turbo which was not run in a test cell after assembly by the remanufacturer, or upon installation of a replacement turbo after a “bearing failure” had occurred. Turbocharger bearing failures are usually a result of an external condition such as an imbalance of the rotating assembly (due to foreign object damage) or to a lack of proper lubrication. Therefore, when an impeller is observed to be rubbing the inside of the air inlet portion of the turbo and no damage is observed on the turbine blades, it is wise to confirm the flow of lube oil through the new turbo prior to returning the engine to service. 1.

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Locate and remove the compressor bearing oil passage pipe plug on the right bank side of the engine turbocharger. This plug is installed in the compressor bearing support, which is the 3” thick casting between the main housing and the air scroll. The 1/2” PT lug accepts a 3/8” male square drive such as that of an ordinary ratchet wrench. The plug will be found above the right-bank turbo air scroll to aftercooler duct mounting flange.

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Temporarily install an oil pressure gauge in the oil passage. Operate the soak-back pump while observing the oil pressure gauge. The gauge should indicate the presence of oil pressure, typically in the 15-30 PSI range. (At the same time, check to make sure that no oil is observed flowing from the engine camshaft bearings - this condition would indicate that the check valve in the turbo filter assembly is defective.) If not oil pressure is observed at the turbo, do not start the engine until the cause is determined.

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Standing adjacent to the flywheel for viewing, energize a stopwatch at the moment when the crankshaft is observed to stop rotating.

7.

Listen carefully for the compressor impeller to stop rotating (identified by the cessation of a whirring sound). Stop the timer immediately.

8.

Due to the momentum of the rotating assembly, the elapsed time should not fall below 27 seconds. Actual run-down times will vary, depending upon the speed of the rotating assembly at the time of shut-down. However, a time of less than 27 seconds from full-speed/full-load indicates that a condition exists which inhibits the rotor from turning freely.

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ADDITIONAL TURBOCHARGER EXTERNAL INSPECTIONS

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It is fact that 60-75 percent of all “turbocharger failures” are caused from an external source such as foreign object damage, overheat/overspeed, lack of proper lubrication, etc. Consequently, unless the damaged turbo undergoes a thorough diagnosis, the condition that existed within the engine which actually caused the failure cannot be determined. Likewise, unless this undesirable condition is corrected, repetitive “turbo failures” can and will occur. The following information is provided in order to help properly identify the true cause of a “turbocharger failure”. The key to the proper diagnosis of turbo problems is to perform ALL the inspections rather than to stop when one condition is observed. In many cases, several symptoms will be present, and all must be reviewed to fully understand what occurred. There are 4 external inspection areas:

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2. Exhaust Outlet Inspection

3. Exhaust Inlet Inspection

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1. Air Inlet & Impeller Inspection

4. External Gears and Oil Drainage Screen Inspection

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Figure 7-28 External lnspection Areas

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AIR INLET AND IMPELLER INSPECTION (Remove Air Inlet Boot to View)

Inspect for the following conditions: a.

Broken Impeller Blades: Indicate possible foreign object damage, or metal fatigue.

b.

Nicked Leading Edges on Impeller Blades: Indicates foreign object passage through air stream. Check air filter box, air duct, and replace air filters.

C.

Blade Rub on Inside of Cast Iron Impeller Cover: Indicates loss of support of turbine wheel in the form of a compressor, turbine, or thrust bearing failure. However, the cause of the bearing failure must also be determined. Continue with the inspections. NOTE: Always replace air filters and check aftercooler cores, aftercooler ducts, and air box for aluminum debris.

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Impeller Locks-Up When Rotated Clockwise: Turning the impeller by hand in a counter-clockwise direction should result in a freewheeling condition. When turned clockwise, the impeller should “lock-up”.If the impeller free-wheels in both directions, either the clutch has failed completely, or a planetary system failure has occurred. If the impeller cannot be turned in either direction, the rotor is locked-up, and the inspection should continue.

EXHAUST OUTLET INSPECTION: (View Down the Exhaust Duct of the Turbo)

Inspect for the following conditions: a.

Warped Exhaust Diffuser: Exhaust diffuser vanes will appear to be “wavy” when viewed from above if the turbo has been subjected to an “Overheat-Overspeed” condition. The thermal expansion which occurs at escalated temperatures causes the part to “grow”. The diffuser is secured in position within the turbo by a series of metal rods. If it becomes overheated, this expansion forces the thin metal vanes to distort permanently. A warped diffuser is always an indication of excessive engine exhaust gas temperatures.

When a condition exists within an engine that results in excessive exhaust heat energy, the high heat level causes the turbine to spin faster than normal. Consequently, the name “Ov&eet-Wetspeed” is associated with this phenomenon. As the turbine spins faster, the blades begin to soften and stretch, and may eventually bred. Also, the impeller tries to pull the turbine wheel forward, out through the air inlet. This overloads the thrust bearing and usually causes it to fail as well.

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Electrdvlotive Model 567.645 & 710 Series Diesel Engines

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Typical causes of excessive heat energy are:

G 1. Broken Piston Rings 2. Worn Injector Tips 3. Broken Exhaust Valves 4. Improperly Timed Fuel Injectors 5 . Incorrect Valve Timing 6. Plugged Aftercooler Cores 7 . Plugged Engine Air Filters

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Any of these conditions can provoke either an “Air Box Fire” or an “Exhaust Manifold Fire”. Evidence of such fires will be found in the form of gray colored ash at localized areas where the fire occurred. Thus, it is necessary to inspect the air box and the exhaust manifold with a bright lamp whenever an Overheatloverspeed failure claims a turbo. Unless the condition is detected and corrected, it will continue to damage replacement turbos.

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Air boxes should be cleaned whenever a thick, wet, sponge-like soot deposit accumulates to depths approximating l/2”. The cause of the deposit formation must be found and corrected.

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Bulged or Punctured Turbine Shroud: The turbine wheel blades are surrounded by a band or shroud. The clearance between this shroud and the blade tips is quite small. Consequently, in the event that an Overheatloverspeed occurs, any plates which stretch will likely contact the shroud and deform or bulge it. In cases of blade breakage, the shroud may become punctured.

C.

Broken Shroud Retainer Clamp: A narrow clamping ring is used to secure the shroud in most turbos. In some cases, this clamp may break due to metal fatigue. If this is observed, the turbo must be removed immediately. If the shroud drops from its pilot, it will damage the turbine blades.

d.

Oil Out of the Exhaust Stack: The seals in the turbo require air to function properly. If the Engine Air Filters are restrictive, the turbo seals may be starved for sufficient air. Check the filter pressuredrop prior to changing the turbo. Also, the source of the oil may be within the engine itself. Before changing the turbo, remove the exhaust screen and check the turbine inlet for wet, shiny deposits, which indicate the oil is coming from the engine, not the turbo.

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EXHAUST INLET INSPECTION:

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(Remove Inlet Screen to View) a.

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Wet, Oily Deposits: The inlet should appear to be dry, with a light amount of flat-black, sooty coloring. If wet, shiny deposits are observed, the engine prob ably has an oil control problem, and an exhaust manifold or air box fire may occur at any time. Bent or Plugged Nozzle Ring Passages: Using a bright lamp, view into the turbine exhaust inlet. The nozzle ring, which is a series of stationary vanes, will be observed. Exhaust gas must flow through this ring in order to act upon the blades in the rotating assembly. If the nozzle is dented and bent, it is generally an indication of foreign object passage. Also, deposits formed on the openings indicate an engine problem such as a cooling water leak. Deposits can also form due to the type of fuel used. In any case, the restriction to gas flow imposed by dented or plugged nozzles can cause the turbo to surge or “burp” at higher engine speeds. This is an undesirable condition. Nicked or Broken Turbine Blades: The blades around the rim of the turbine wheel cause the rotating assembly to spin whenever exhaust gas flows through them. If they are nicked, foreign material has passed through with the gas. This material is generally in the form of small, sharp pieces of broken piston rings or exhaust valves. The nicked blades in the turbine wheel unbalance the highspeed rotating assembly, and a compressor or turbine bearing failure will generally occur if the turbo is permitted to remain in operation. In some cases, the blades may break due to: a severe impact; stretching as a result of an overheat/ overspeed; or metal fatigue. In such instances, the rotor unbalance is tremendous and a severe bearing failure is imminent.

EXTERNAL GEARS AND OIL DRAINAGE SCREEN INSPECTION: (Required Turbo Removal)

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Damaged Turbo Idler or Carrier Drive Gears: Damage to the externally mounted gears on the back-side of the turbo is generally an indication of an engine gear train problem rather than a turbo malfunction. In extreme cases, one of these gears may exhibit broken teeth if the turbo rotating assembly is seized. Metallic Debris in Oil Drainage Screen: Located just below the turbo-mounted idler gear is a small triangular-shaped screen*. All lubricating oil from the planetary gear train passes through this screen as it drains from the turbo. Hence, if a planetary gear train component is h k c n , the oil drainage will carry this debris with it, and will deposit the chips against the inside of the screen.

* The triangular screen was replaced with a larger, internal screen in 1988.

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ElectroMotiveModel 567,645 8t 710 Series Diesel Engines

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ADDITIONAL TROUBLESHOOTING INFORMATION

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Check engine air filters for plugging. A lack of air to the turbo’s labyrinth seals will cause oil migration across the seals, especially at higher speeds.

2.

Remove eductor tube and inspect lube oil separator assembly. Check for damaged or missing screen, which would allow oil to be drawn out with crankcase vapors.

3.

Remove the expansion joint between the turbo exhaust inlet and the exhaust screen assembly. Inspect the turbine inlet scroll. If coated with wet, shiny oil, the source of the oil out of the stack is within the engine. Inspect the engine in accordance with the Maintenance Manual to determine the source of the oil in the exhaust gas.

4.

If the turbine inlet is dry, the turbo may have a true seal problem. Since

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labyrinth seals are non-wearing components, they have either plugged due to dirt or have become physically damaged from contact with the rotor as a result of a bearing failure. At this point, the turbo must be removed.

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Exhaust Leaks 1.

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Exhaust leaks usually occur at the expansion joints between the exhaust manifold sections or at the connection to the turbine inlet scroll. These leaks are dangerous to operating personnel, and detract from the turbo’s efficiency.

If a crack is found in the turbine inlet scroll, no repair in-place will be successful. The turbo must be removed.

Noise Identical turbos can make varied sounds due to manufacturing tolerances and operating characteristics. Generally, noise should not be a factor when determining a turbo’s condition. Exceptions would be loud screeching noise or severe humming accompanied by vibration. Turbos commonly emit “chirping” noises, particularly at low speeds such as idle. Also, it is common to hear a “chirp” in varying cadence when releasing the injector control lever from higher engine speeds. This noise is simply the turbine coming back onto the gear train.

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ITS Locomotive Training Series - Student Text

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Burping and Smoking This symptom indicates a reversal of the normal exhaust gas flow through the engine and turbocharger. There is typically an approximate 2 psi drop across the engine power assemblies. This means that air box pressure is 2 psi greater than exhaust manifold pressure throughout the speed range. If this condition changes, whereby exhaust pressure exceeds air box pressure (momentarily), a surge or burp will occur. This relieves the excess pressure through the turbo air inlet, and engine operation may return to normal until the back-pressure builds once against. A surging condition is detrimental to the turbo. First, the hot exhaust gas reversal into the engine air box may ignite any combustible deposits in the air box, causing an air box fire and resultant turbo overheat/overspeed. Second, the load imposed upon the clutch and planetary gear drive system is significant.

When surging occurs, the following procedure should help in determining the cause:

1. Locate another engine of the same type and model; i.e., 16-645E3B. 2. Install a 0-30 psi pressure gauge on a modified handhole cover of each engine. 3. Run each engine at full-speed, no load and record pressure reading.

4. Since each engine was operating on the gear train (due to no load), each turbo was operating as a geardriven blower. Pressure variation should be no more than 1 psi between the two engines.

High Air Box Pressure on Suspect Engine:

1. Check turbine exhaust inlet screen for plugging.

2. Inspect turbine nozzles for plugging and turbine blades or damage. 3. Check cylinder liner inlet ports for plugging.

4. Check valve timing (late?). Low air Box Pressure on Suspect Engine:

1. Check engine air filters for restriction or plugging (max. 13.5” H,O).

2. Check aftercooler cores with manometer for plugging (max. 10’’ H,O). 3. Inspect for air box leak.

4. Test turbocharger for slipping clutch.

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Electro-ivlotive Model 567.645 & 710 Series Diesel Engines

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OVERHEAT/OVERSPEED FAILURE An overheatloverspeed failure is an overspeeding of the turbine wheel which is caused by excessive (overheated) exhaust gas temperature. Exhaust gas temperature will vary with ambient weather conditions, fuel characteristics, engine load, etc. However, normal temperatures generally range from 850 to 1050 degrees F at full speed, full load.

An overheatloverspeed is typically the most destructive type of failure which can occur to a turbocharger. It is caused by conditions external to the turbo such as worn power assemblies and dirty air boxes. Consequently, if the cause is not determined, the replacement turbo will also incur a similar failure.

Normally, a turbine wheel’s speed increases at approximately 450-500 rpm per second during a throttle “wipe”. However, during an overheatloverspeed, it is not unheard of to observe turbine speed increases of 5000 rpm per second. This can be accompanied by dramatic air box pressure increases of as much as 10 psi quite abruptly. If the overspeed occurs while the turbo is operating near its peak rpm (usually 18,500 to 21,500), within one second the speed of the turbine can exceed its safe limits and severe damage will occur. It is impossible to counteract for this condition quickly enough with the technology available today. Therefore, the only way to control overheatloverspeed failures is through preventative maintenance. Typical symptoms of an overheatloverspeed failure are a warped or deformed exhaust diffuser (resulting from excessive temperature) and stretched or elongated turbine blades (due to a combination of softening from excessive heat and lengthening due to centrifugal forces).

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Figure 7-29 Typical OverheatlOverspeed Conditions

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Any of the following conditions, which increase air box temperature, are contributors to overheat/overspeedfailures:

1.

Dirty Aftercoolers 2. Broken Compression Rings 3. Late Injector Timing 4. Incorrect Valve Timing 5. Plugged Exhaust Screen 6. Plugged Engine Air Filter 7 . Damaged Injector Tips 8. Exhaust Manifold Fire

FOREIGN MATERIAL DAMAGE TO TURBINE The mechanical break-up of any part of a power assembly or exhaust system component can result in foreign material damage to the turbine nozzle ring and turbine wheel blades. Common sources of foreign material are broken compression rings resulting from too much side clearance and fragments of an exhaust valve head which is disintegrating due to improper lash or excessive temperature. The turbocharger is reasonably protected from this material by the exhaust screen. However, since the screen must flow a large volume of gas with a minimal restriction, small objects can pass through. Also, larger sharp objects can eventually tear the screen grid and pass through to the turbo. Consequently, the exhaust screen should be periodically removed, cleaned and inspected. Any time that an indication of foreign object damage is observed, the source must be identified and corrected to prevent turbocharger failure. Due to the high rotational speed of the turbine wheel, small nicks near the outside diameter on the turbine blades cause serious unbalance of the rotating assembly, This unbalance is very detrimental to the turbo bearings, and will bring about their failure. Consequently it is recommended that whenever foreign material damage is observed in the turbine section, the turbo should be removed prior to running it to destruction and thereby increasing its repair cost.

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Typical Foreign Material Damage

Figure 7-30 Nicked Blade and Nicked Nozzle Ring

h 7-40

ElectroMotive Model 567. 645 & 710 Series Diesel Engines

13' I

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FOREIGN MATERIAL DAMAGE TO COMPRESSOR IMPELLER Since the air inlet of the turbocharger is protected by a highly effective air filter, this type of damage should not be common. On the contrary, a surprising number of turbochargers fail due to this condition. Damage such as nicks to the leading edges of the compressor impeller blades result in the same serious unbalance condition and consequences as that of nicked turbine blades.

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c c

c c

Figure 7-3 1 Nicked lmpeller Blades

This type of failure is usually a result of one of the following:

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1.

Previous turbocharger failure, whereby broken pieces -.Jm the previous compressor impeller were driven into the air filter of filter housing and not removed.

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2.

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Misapplication of the compressor inlet boot or clamp. The clamp must be tightened squarely on the inlet or it may vibrate loose and enter the turbo.

CLUTCH FAILURE

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The clutch is one of the few areas of the turbo where there can actually be metal to metal contact during operation. Thus, it is a wearing item. EMD’s current recommendation is to replace the turbo to prevent clutch failure every 4 years or 24,000 hours of operation.

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Clutch life can become adversely affected if the turbo is subjected to:

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2. 3. 4.

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1.

Abnormal vibration levels due to rotor imbalance. Worn planetary gears. Frequent abnormal cycling such as from surging. Contaminated lubricating oil.

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ITS Locomotive Training Series -Student Text

7-41

a

3 3

r

Roller “Skid“ Mark

\

Worn Ramp

Polished Ramp

(Grooved)

(Shiny-No Groove)

Figure 7-32 Camplate Ramp Wear

LACK OF PROPER LUBRICATION This mode of failure may occur due to a malfunction in the lubrication system such as a failed soakback pump, failed lube oil pump, blockage in a lubricating passage, or contaminatedhnacceptable oil. Other possible contributors include interruption of the soakback oiling prior to the completion of its timed cycle, and excessive engine rpm immediately following start-up. It is possible to “wipe”a bearing during engine start-up unless the injector control linkage is manually controlled to avoid great speed increases, particularly during cold ambient weather conditions. In the case of a lack of lubrication failure, most if not all, of the six bearings in the turbo may exhibit distress such as smearing to varying degrees. Since the compressor thrust bearing is typically the most heavily loaded surface in the turbo, the amount of damage sustained there is usually greater than that of other areas such as planet bearing surfaces. Since the turbo relies on the engine for its lubrication, this is yet another mode whereby the root cause of one failure must be corrected prior to the installation of a replacement turbo. Also, upon the installation of the replacement, it is good practice to confirm that oil pressure is actually reaching the turbo by carrying out the Turbocharger Oil Pressure Test. Oil pressure must be observed during soakback pump operation prior to engine start-up, or the replacement turbo will fail.

BEARING FAILURES Turbocharger bearing failures rarely occur without an external ontributin input. These inputs generally are rotor unbalance due to foreign material damage, over1 at/ overspeed, or lack of proper lubrication. Consequently, the failed turbo must undergo a thorough inspection in order to identif) all of the related failure modes. Once this has been accomplished, the sequence of events leading up to the failure can be reconstructed in order to arrive at the root cause of the bearing failure. Misapplied aftercooler ducts can also cause bearing failures through distortion of the doweling assembly. 7-42

Electro-MothteModel 567, 645 & 710 Series Diesel Engines

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c c. Cli

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c c

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For example, if the impeller has rubbed the cover, obviously a bearing failure has occurred. However, further inspection may reveal nicked turbine or impeller blades, which are caused by foreign object passage and lead to rotor unbalance. Therefore, the conclusion should be that foreign material struck the rotor, causing a vibration. This unchecked turbo operation in a vibrating condition resulted in the breakdown of the oil film on the bearing surface, and a smear on the bearing took place. The smeared bearing eventually progressed to a loss of support for the turbine wheel, and the impeller rubbed the inside of its cover. Unless the cause of the foreign material is identified and corrected, the replacement turbo is likely to fail in an identical manner.

Smeared

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Oil /Channel

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Figure 7-33 Smeared Bearing

In some cases, it may be possible to determine which bearing has failed or has suffered the most severe distress by means of an external inspection. The key to this identification lies in the location of the heaviest concentration of aluminum particles on the inside of the impeller cover. In each case, each of the impeller blades will be rubbed at their edges, representing 360 degrees of damage to the impeller. However, the impeller cover can provide clues concerning the major bearing distress.

If the aluminum particles are evenly distributed 360 degrees around the inside of the cover, it is safe to assume that the thrust bearing failed, and the rotor moved forward. If the aluminum is primarily located in the bottom or 6:OO position of the cover, the compressor bearing has failed and that end of the rotor has dropped. Conversely, if the aluminum concentration is primarily at the top or 12:OO position, the turbine bearing has likely failed and allowed the sun gear end of the rotor to drop, raising the impeller end. In any event, the diagnosis must continue so as to determine what condition brought on the bearing failure in the first place. ,,, 8

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ITS Locomotive Training Series -Student Text

7-43

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PLANETARY GEAR TRAIN FAILURE The planetary gear train is another area where damage without external input is rather unusual. Although the gears are considered wearing parts, their design is such that they should not wear out within the prescribed turbo service life. However, vibration and heavy loading for long periods are detrimental to long gear life.

If the engine operates for long periods at light-load, the demand on the planetary system is dramatically increased and rapid gear wear can result. Once this gear wear becomes excessive, the mesh of the gears becomes “loose” and initiates a high frequency vibration. The existence of this condition is confirmed at the time of turbo disassembly, since the planet bearings will exhibit erosion of the silver plating at the end of the oil ramps. Oscillation of the sun gear within the planetary system can also produce a similar erosion of the turbine bearing. Furthermore, the planet gears themselves may actually strip, causing a complete loss of drive for the turbine. In such cases, the initial symptoms would parallel those of a clutch failure. However, upon removal of the turbo from the engine, metal debris would be visible in the turbo oil drain screen and possibly even on the “ledge” of the turbo main housing near the spring drive gear.

Figure 7-34 Broken Planet Gears Erosion

Erosion

I

Noraal Planet Bearing

Eroded Planet Bearing

Eroded Turbine Bearing

Figure 7-35 Eroded Bearing Conditions

. .. 4

In extreme cases, the vibration of the planetary system can lead to turbine blade fatigue. This condition involves the breakage of one or more turbine blades at a high stress location through simple metal fatigue. In the event of a planetary failure, the engine oil pan, oil strainers, and the oil itself should be checked for the presence of debris. Also, the oil filters should be changed. The external turbo gears, as well as those in the engine camshaft drive gear train, should be inspected for damage. The bolt torque on the spring drive gear should also be verified, since the shock loading brought on by such failures can sometimes break these fasteners.

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7-44

ElectroMotive Model 567, 645 & 710 Series Diesel Engines

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TURBINE BLADE FATIGUE Turbine blades may break off the rotating assembly through metal fatigue. Although rather uncommon, once this has occurred, the damage to the entire turbo is considerable. This is due to the extreme unbalance condition which results when so much mass it removed from one side of the wheel near its outside diameter. In many cases, the rotating assembly shaft will actually bend just ahead of the compressor journal, swinging the impeller out towards the “light” side of the wheel. Turbine blade fatigue can occur as a result of a high frequency vibratory input from a poor planetary gear system mesh. It also can result from a manufacturing defect of the blade itself. Generally speaking, manufacturing related problems tend to cause fractures early in the life of the machine, while gear mesh problems may occur after a considerable length of service has been reached.

Figure 7-36 Blade Fatigue Fracture

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FA1LURE CLASS1FlCATlON

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Key Components in Evaluating a Turbocharger Failure:

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1. Turbine Blades 2. Impeller and Cover 3. Exhaust Diffuser

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4. Turbine Shroud 5. Nozzle Ring 6. Planet Gear Train 7. Bearings

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Turbocharger failures have been classified into a group of distinct types or “modes”. Each failure’mode has specific characteristics and is known by the areas of distress which are exhibited. The following list contains the most common failure modes, and a brief description of the areas of distress which can be used for root cause determination.

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OVERHEAT/OVERSPEED

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1.

Exhaust diffuser distorted or “warped” indicating severe thermal distress.

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2.

Turbine shroud bulged and deformed from elongation of turbine blades.

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ITS Locomotive Training Series Student Text

7-45

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3

3.

Rotating assembly “frozen” (unable to turn) due to elongated turbine blades. Blades soften at excessive temperature, and stretch due to centrifugal force until they either contact the shroud or simply separate in the center of the airfoil portion.

4.

Presence of grayish-colored ash deposits within the engine air box or exhaust manifold. The greatest concentration of this ash will indicate the location of the fire’s origin.

5.

Blistered paint on air box handhole covers.

6.

Subsequent damage frequently associated with overheat/overspeed: a. b. c. d. e.

Bearing Failure (thrust, compressor, or turbine) Impeller Rub Clutch Failure Planet Gear Train Damage Labyrinth Seal Damage

FOREIGN MATERIAL D A M A G E T O TURBINE SECTIONS 1.

Nozzle ring nicked, dented or bent on front or back.

2.

Turbine blades nicked or torn on leading edges. \

3.

Subsequent damage frequently associated with €oreign material: a. b. c. d.

Bearing Failure Labyrinth Seal Damage Impeller Rub Clutch Failure

THRUST BEARING FAILURE 1.

Compressor impeller blades rubbed on inside of impeller cover.

2.

Thri.1.at bearing ramps smeared.

3.

Subsequent damage associated with thrust bearing failure: a. Planetary Gear Train Failure

b. Turbine Blade Breakage or Exit from Rotor c. Exhaust Diffuser Damage

7-46

Electro-Motive Model 567, 645 & 710 Series Dlesel Engines

3 i d

c

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c C G

c e

COMPRESSOR BEARING FAILURE 1.

Impeller rub on cover (primarily at bottom).

2.

Subsequent damage which may accompany compressor bearing failure: a. b. c. d.

c

c c c

Labyrinth Seal Damage Turbine Blade Tip Rub Planet Gear Train Failure Clutch Failure

TURBINE BEARING FAILURE 1.

Impeller rub on cover (primarily at top). Subsequent damage: See Compressor Bearing Failure.

c

2.

c c c

ROLLER CLUTCH FAILURE

c G G

1.

Heavy carbon deposits on compressor impeller and engine air box.

2.

Inability to start engine.

3.

Smoke from engine exhaust (particularly during speed changes).

4.

Subsequent damage which could possibly occur due to clutch failure:

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a.

Air Box Fire (due to heavy carbonaceous deposit formation).

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e

FOREIGN MATERIAL D A M A G E T O COMPRESSOR SECTION 1.

Nicked or torn impeller blades.

2.

Subsequent damage which can occur as a result of foreign material:

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a. b. c. d.

c

c 6 G C

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Dented or Bent Compressor Diffuser Vanes Bearing Failure Impeller Rub Labyrinth Seal Damage

e. Clutch Failure

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c.

PLANETARY GEAR TRAIN FAILURE 1.

Inability to start engine.

2.

Subsequent damage which can accompany planetary system failure: a.

Engine Rear Gear Train Damage

ITS LocomotiveTraining Series - Student Text

7-47

g

.

.

LACK OF PROPER LUBRICATION 1.

All internal bearings exhibit distress (smearing, discoloring).

2.

Subsequent damage from lack of lubrication: a. Turbine Wheel Damage (impeller rub, blade tip contact; journal scoring, grooving or discoloration) b. Clutch Failure c. Planetary Gear Train Failure

TURBINE BLADE FATIGUE FRACTURE 1.

One or more turbine blades broken off at first serration in base.

2.

Turbine blade(s) broken off above base in airfoil section. (In either case, no signs of overheat/overspeed or foreign material damage will be present, simply a broken blade.)

3.

Subsequent damage which frequently accompanies blade fatigue: Bearing Failure Impeller Rub Clutch Failure C. d. Torn Exhaust Diffuser e. Punctured Turbine Shroud f. Planetary Failure g. Exhaust Duct Deformation h. Broken Turbine Wheel I. Loose Bolts in Turbo Cradle Area (severe vibration) Cracked Doweling Assembly Components 1.

a. b.

EXHAUST GAS LEAK 1.

Identified by presence of carbon on side of exhaust duct (on either the seal ring side or lap joint side).

TURBINE SHROUD RETAINING CLAMP FAILURE 1.

Clamp loose or missing when viewing down exhaust duct.

2.

Shroud displaced, bent or missing.

3.

Subsequent damage which may accompany clamp failure: a. b.

7-40

Turbine Blade Tips Rubbed Bearing Failure ElectrMotive Model 567,645 & 710 Series Diesel Engines

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C

c c

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POOR PLANETARY GEAR TRAIN MESH 1.

Eroded planet bearings.

2.

Fatigue fracture of turbine blade.

3.

Planet gear or sun gear broken.

4.

Subsequent damage which may occur:

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a.

b. c.

Rotating Assembly Distress Clutch Failure Impeller Blade Fatigue Fracture

INTERNAL OIL LEAK 1.

Oil out of stack (no filter problems, no engine oil loss).

EXTERNAL GEAR DAMAGE 1.

Broken gear teeth on either idler or carrier drive gear.

2.

Damage on turbo drive gear portion of spring drive assembly.

3.

Subsequent damage which may occur: a. b.

Clutch Failure Planetary System Failure

TURBOCHARGER INSTALLATION TIPS The following precautions should be taken to minimize the risk of repetitive turbocharger failures:

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G G

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a. Inspect exhaust manifold and screen for foreign material or cracks. b. Inspect engine gear train for damage. c. Inspect engine air filter housing for debris or cracks.

d. Replace engine air filters. e. Replace engine oil filters if previous failure contaminated oil. f. Inspect aftercoolers for deposits and debris. g. Inspect engine power assemblies and air box. h. Check valve and injector timing.

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ITS Locomotive Training Series - Student Text

7-49

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3 1.

Determine impeller “eye” clearance on replacement turbo prior to installation on engine as follows: a.

Remove turbo from box.

b.

Chalk mark one impeller blade at 1200 position.

3 cp 3 3 Ls

C.

Insert same thickness feeler blades at opposing blades between blade edge and impeller cover to determine clearance. Record:

d.

Install turbo on engine.

3 3 3 3

e.

Install aftercooler ducts:

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1200 16:OO Positions = 3:OO 19:OO Positions =

L)

1. Snug bolts at turbo end of duct 2. Torque bolts at engine end of duct (65 ft. lbs.). 3. Remove bolts from turbo end of duct. 4. With gasket in place, confirm that .008” feeler will not enter. 5. If .008” feeler enters, loosen and reposition duct on engine. 6. If necessary, holes in engine end of duct may be enlarged. 7 . Torque engine end bolts, repeat flange check. 8. Torque turbo end bolts.

f.

Repeat “eye” check now with turbo mounted:

1. Position chalk-marked blade at l2:OO. 2. Verify that all four readings are unchanged. 3. If readings cannot be repeated, loosen aftercooler bolts and re-align (if hole enlargement required, ream engine-end holes). g.

7-50

If previous failure could have resulted from lubrication problem, such as an unexplained bearing failure, confirm oil flow to turbo prior to start-up. This can be accomplished with the soakback pump. Instructions can be found on page 4-3 under Turbocharger Oil Pressure Test.

ElectreMotive Model 567,645 & 710 Series Diesel Engines

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cup 3 3 3 rclr)

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Oil seals in each end plate seal the rotor shafts to prevent oil from getting into the rotor housing .The rotor drive gears are splash lubricated and the lubricating oil is returned to the engine sump by an external drain line located at the bottom of the rear cover. Each blower is driven by a splined drive hub that is bolted to the blower drive gear which is driven by the camshaft drive gear. The splines of the drive hub mate with the splines of the quill shaft which has a flange on the other end which is bolted to one of the blower rotor gears.

From Engine Filter

To Air Box

Figure 7.39 Blower End View Cross Section -Air Flow

Blower Inspection Blowers should be inspected at intervals specified in the Scheduled Maintenance Program. They can be viewed by removing the rear air box covers and looking up through the blower support housing. Any signs of aluminum dust in the blower support housing or air box indicates blower bearings that have become worn enough to cause rotor interference. Any blower showing aluminum dust should be renewed as soon as possible. Oily rotor lobes, oil in the air box, and oil running down the blower support are signs of leaking oil seals, which indicates the blower should be changed. Clean strips on the rotor tips is a normal condition, caused by the close clearances between the rotors and the rotor housing. Also small scratches may be found on the clean strips, caused by dirt particles which have found their way into the blower, but these usually do not cause a problem, unless aluminum dust is present.

EXHAUST SYSTEM COMPONENTS rcJ,

Exhaust Manifold Function is to collect exhaust gases and remove them from engine with minimal restriction. Systems are comprised of sections which may span 1,2, or 3 pairs of cylinders and are interconnected.

7-52

Electro-MotiveModel 567, 645 & 710 Series Diesel Engines

3 3 9

-)3 13 w

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Blower Engine Exhaust System Blower type system uses outlets or stacks, which number from 1 through 4 on various applications. Manifold sections connected to one another with strap-type clamps

NOTE: All sections have 114” drain holes at bottom. Three basic manifold types: Standard - Basic low restriction design.

c

Spark Arrester - Has “traps” to collect carbonaceous particles to avoid throwing this material out stack. (Approved by U.S. Forestservice.)

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c

SilencerEpark Arrester - Similar to Spark Arrester type, but incorporating a silencing chamber to reduce noise.

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Figure 7.40 Typical 16 Cylinder Standard Exhaust System

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Figure 7.41 Typical Turbocharger Engine Exhaust System

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ITS Locomotive Training Series Student Text

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Screen Inspection Port The Screen Inspection Port must be periodically inspected for damage or plugging. The port makes inspection easier and eliminates removal of screen for inspection. EMD has a kit available to retrofit existing manifolds under part number 9336983. Refer to MI 9622 for installation details. This kit is designed for 645 rear manifold chamber and is not intended for 567 straight barrel. The inspection port provides 4” opening for viewing the condition of the screen.

Screen Inspection Port

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ullL._i Figure 7.42 Screen Inspection Port

NOTE: Screen still requires removal for cleaning.

Screen Assembly The screen assembly is located between turbocharger and rear manifold and is manufactured with numerous small diameter openings designed to prevent passage of foreign material. This protects the turbocharger (within limits) from broken power assembly components such as ring or valve fragments. Such material can destroy the turbocharger if it strikes the blades of the critically balanced turbine wheel. The screen is susceptible to plugging from carbon (souping), water treatment residue (cracked head or liner), etc. Plugged screen lowers turbo efficiency arid ultimately causes “burping” due to gas flow restriction. The screen plate attached to metal support strips within housing to allow thermal expansion without tendency to fracture.

I7-54

Screen

Figure 7.43 Typical Exhaust Met Screen.

Electro-Moti Model 567.645 & 710 Series Diesel Engines

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. . .

.

. .

There are three major design variations:

1.

Standard (8358828) - Grid pattern of approximately 1/8” diameter holes.

2.

Trap - Type (8482700) - Same as above, but included small pocket located at bottom of housing to catch foreign objects and prevent them from repeatedly gouging at screen.

Objects would eventually tear screen or wear themselves down until small enough to pass. Trap keeps foreign material out of gas flow. Clean-out plug intentionally omitted from design to require screen removal. In this way, the exhaust manifold can be inspected for further debris. 3.

c

Reduced Gradient “Starburst” Type P/N 9526331 - Included trap as above, but screen plate featured revised hole pattern. Holes positioned in radial lines from center outward. Resulted from tests indicating thermal expansion pattern was same. This screen’s service life is approximately double that of its predecessor. All 645 screens are now converted to this type. Figure 7.43 illustrates a typical “Starburst”type screen assembly.

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c G c, C G G

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Exhaust System Data Engine Model

Turbine Inlet Temp

16-567C 16-645E3 20-65E3 16-645F3 16-645E3C 16-645F3B

900 (Ex Out) 870 Turbine In 930 Turbine In 980 Turbine In 864 Turbine In 880 Turbine In

Ex Gas CFM 14,100 21,100 22,900 23,750

--

19,975

Air Box Pressure

4-5 psi 17.5 18.4 20.5 19.5 21.8

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ITS Locomotive Training Series -Student Text

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CHAPTER Engine Speed Control

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Introduction

deals only

The engines covered in this program are equipped with a Woodward PGR governor as shown in Figure 8.1 which:

With

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conventional engine control.

regulates the amount of fuel delivered to the engine cylinders by the fuel injectors.

G G

EMDEC is covered in a separate training

assists in controlling main generator output by regulating main generator excitation through the load regulator.

G

Program.

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b

By balancing generator load with a set engine speed, the governor maintains a constant kilowatt output by the engine/generator combination for each throttle position. Speed selection is accomplished through the actuation of combinations of electric solenoids within the governor; fuel control through the governors internal hydraulic system, hence the term electro - hydraulic. The governor senses engine RPM and adjusts the position of the layshaft, which in turn regulates fuel injector output to maintain engine RPM at the operator selected level.

The Woodward governor is a complex precision device; it will be covered in depth in a subsequent course however, this chapter will briefly cover some of the significant points.

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c G

ITS LocomotiveTraining Series - Student Text

8-1

a

3 The governor has three main systems:

3 u)

speed sensing speed control load regulation

It also has a completely self contained hydraulic system with reservoir, pump, and accumulators to lubricate the internal parts and operate various parts of the governor,

EL9ctfidReceptacle Ecgine Oil Pressure Connection 13. nme m!ayk u m u $ t o r 14. RebaknCng Servo Oil Filter 15. VentPM 11. 12.

The governor has protective devices which will shut the engine down should there be a loss of pressure in the engines' lube oil system or a failure of the engines cooling system. Figure 8-1 Woodward Electro-Hydraulic Governor

16. OilDrainCock 17. T e n i d Shaft control

3 3 3 3

3 3 3 3

19

3 kJ)

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Speed Sensing and Fuel Control The basic operation of the Woodward governor is illustrated in Figure 8.2. Fuel Limit Lock Nut Fuel Limit Nut 0.79 mm (1/32") Gap At Idle

Shutdown Rod Bushing Locknut Shutdown Bushing

Speed Setting Piston

22293

Figure 8.2 Basic Operation 8-2

ElectroMotive Model 567,645 & 710 Series Diesel Engines

3' 3 3

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The governor drive shaft is driven from the accessory gear train through an angle drive unit and provides the energy to drive the governors components and sense and respond to changes in engine speed. This drive shaft turns the enclosed hydraulic gear pump, the flyweight assembly and the rotating bushing which encloses the pilot valve. As the governor rotates, oil is pumped into accumulators to provide a working supply of oil under pressure for the governor. The flyweights are mounted on pivots and held inwards by the pressure of the speeder spring on their fingers. These fingers are also connected to the top of the pilot valve that controls the flow of oil to and from the power piston.

As the engine is started, the centrifugal force of the flyweights is insufficient to overcome the pressure of the speeder spring. The pilot valve is held down and allows oil to flow from the accumulators, through the rotating bushing, and through the buffer piston to the underside of the power piston. Oil pressure under the power piston builds up and overcomes spring pressure to move the piston upwards. Fuel injection rates are controlled by the power piston, which through the layshaft and racks, controls the fuel injectors. Raising the power piston moves the layshafts, which in turn move the injector racks inwards to a higher fuel position.

As more fuel is delivered to the engine and speed increases, centrifugal force on the flyweights causes them to move outwards, raising the pilot valve plunger and shutting off the supply of oil to the underside of the power piston. This action maintains fuel delivery, and engine speed, at a set level. Should engine speed increase beyond desired, the weights move outwards further, raising the pilot valve plunger. This opens ports to allow oil to drain back from the underside of the power piston. The power piston moves down, cutting back the amount of fuel delivered to the engine. Engine RPM stabilizes in the "balance" position, controlled by the action of the flyweights and speeder spring pressure.

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ITS LocomotiveTraining Series - Student Text

8-3

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Speed Control In the last section we saw how the governor maintains engine speed in the "balance" position. Now we will look at how the governor responds to changes in the throttle position by means of the speed setting system (Figure 8.3) Speed setting of the governor is accomplished by energizing different combinations of the four electric solenoids (A,B,C,D). The A, B, and C solenoids have plungers that bear on a triangular plate, attached to a fulcrum point on a lever. Each of these three solenoids is positioned at a different distance from the fulcrum point of the plate.

By energizing different solenoids (or combinations of solenoids) the plate is depressed to different levels.

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Pressure Oil $5Trapped Oil

Intermittent Oil I intermediate Oil

Figure 8.3 Speed Control

The lever is attached to the top of the speed control pilot valve on one end; and through linkages to the top of the speed setting piston on the other end. The D solenoid is attached to another rotating bushing which surrounds the speed setting pilot valve. When the throttle is moved to a higher position, calling for more engine speed, one solenoid (or a combination of solenoids) are energized. Energizing the solenoids causes the triangular plate to be depressed. Through the plate and lever, the speed setting pilot valve is depressed, allowing oil to flow to the top of the speed setting piston. 8-4

Electro-Motive Model 567.645 & 710 Series Diesel Engines

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0

3

a !3

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3

Load Regulation The next part of the governor to be covered is the load regulation system (Figure 8.4). This system controls the excitation of the main generator, and balanced with engine RPM, the power output. This section provides a brief description of the operation as system will be dealt with in detail in later courses. The system uses linkages and a load regulator pilot valve to control oil flow to and from the load regular vane motor.

Figure 8.4 Load Regulation

The vane motor operates a resistor that controls the current used for main generator excitation, and therefore output. (on microprocessor controlled locomotives, the load regulator sends a reference signal to the computer to control loading). 8-6

Electro-MotiveModel 567,645 & 710 Series Diesel Engines

c c

c G

c;

c

If the horsepower demand is less than or greater than the engine is adjusted to develop for a given RPM, then this system will increase or decrease generator excitation

c

(and therefore output) to meet the changed demand.

L G

If the horsepower demand is less than rated, oil is directed to one side of the vane motor to increase resistance in the main generator field circuit, and cut back horsepower developed. At the same time, the governor responds by cutting back fuel delivery to maintain a constant engine RPM.

c c c c

c c c c

c c

If the horsepower demand is more than is proper for a set engine speed, again the load regulator system will limit the main generator output and engine fuel delivery to maintain a maximum rated output. In addition to basic load regulation, the system also compensates for engine performance variations caused by barometric pressure changes. Should barometric pressure (or airbox pressure) reduce, the load regulator system is affected by the change in pressure. The lower the air box pressure, the sooner the load regulator will limit main generator excitation. Another component of this system is the overriding solenoid (ORS),which when energized by other systems, such as wheel slip, will act to reduce excitation.

Protective Devices

CJ

G

c

The low lube shutdown system protects the engine in case of a failure of the mechanical support systems.

c

The shutdown system can be activated by:

c

1.

"True" low lubricating oil pressure;

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2.

"False" low lube pressure caused by a failure of i e cooline svstem ant detected by either of the low cooling water portion of the E.P.D. or hot oil detector;

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"False" low lube pressure caused by the E.P.D. sensing a positive crankcase pressure (crankcase is normally under a slight vacuum);

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"False" low lube pressure caused by manual engagement of the system connected to a lube oil line from the engine on one side and speed setting oil pressure on the other side.

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u cus 3 ts 3 3 Figure 8.5 Low Lube Oil Shut Down

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Should oil pressure in the line drop below the speed setting oil pressure, the system will take action to shut down the engine.

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When the engine is at idle, there is a mechanism that builds in a delay of 50 to 60 seconds. This delay is to allow oil pressure to build up when starting the engine. The delay is reduced in steps to the third throttle position. In the fourth position and higher there is no time delay in the shut down system.

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To shut the engine down, the system bleeds the speed setting oil from the top of the speed setting piston. The governor reacts by moving the layshaft and racks to the no fuel position, shutting down the engine.

A switch is tripped setting off an alarm in the operators cabin, and a plunger protrudes from the side of the governor exposing a red band. The engine cannot be restarted until this plunger is reset. The hot oil detector and engine protective device both simulate a loss of oil pressure by bleeding oil pressure off of the line to the governor.

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Eiectro-Motive Model 567,645 & 710 Series Diesel Engines

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Governor Maintenance Governor oil should be changed at regularly scheduled intervals. Always maintain governor oil level to the top mark in the governor oil level gauge. A large percentage of governor problems are caused by dirty oil. Always use clean oil and a clean container when topping up or refilling the governor. Dirt and other impurities can be introduced with governor oil or can form when oil breaks down or forms sludge. Dirt or sludge can cause the valves, pistons, or plungers inside the governor to stick or seize in their bores causing erratic operation and poor response.

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In some instances where it is not possible to remove the governor to disassemble and clean it, governor performance may be restored by flushing the governor with fuel oil or kerosene. Solvents should not be used to flush a governor, as they can damage sea,, and gaskets.

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Governor Flushing Open the drain cock and drain the governor oil.

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Refill the governor with clean fuel oil and restart the engine.

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Using the injector control lever, vary the engine speed from approximately 400 to 500 RPM for about five minutes, then stop the engine and drain the fuel oil from the governor.

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Repeat the process until the fuel oil drained appears clean, then fill the governor with clean governor oil.

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Restart the engine and repeat the above process, then drain the oil to remove any trapped kerosene.

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Fill the governor with clean oil. Adjust the compensation needle valve using the following procedure.

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Compensation Adjustment The compensating mechanism prevents the engine from "hunting" or racing by arresting the movement of the power piston after it has travelled a sufficient amount to give the desired speed. Compensation adjustment is the only adjMsDent that is recommended-to be done with the governor on the engine. All other governor adjustments should be done on a calibrated test stand by specially trained personnel. Adjustment of the compensation mechanism is required when an engine is being started for the first time, after installation of a new or reconditioned governor, or after a governor has been drained and cleaned and new oil added.

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ITS Locomotive Training Series Student Text

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This adjustment purges the governor oil system of trapped air. Adjust the compensation as follows: Ensure that the governor oil level is between the lines on the sight glass.

Start the engine and operate at idle speed. Open the compensating needle valve by turning counterclockwise several turns. Loosen the vent plug several turns, but do not remove it. The engine will hunt and surge, and air will bleed from the system at the vent plug. When onlv oil flows from the vent plug, slowly close the compensating needle valie until the hunting stops or slows. Tighten the vent plug to prevent oil leakage, and add oil to the governor if necessary. Allow the engine to reach normal operating temperature, then open the compensating needle valve and allow the governor to hunt. Close the needle valve until the hunting stops. Test the governor by changing speeds with the injector control lever observing the governor recovery. If the governor returns to a steady speed, the adjustment is satisfactory. If hunting resumes, close the compensating needle valve slightly then test again. This compensating needle valve should be kept open as far as possible to prevent sluggishness and still maintain even governor operation. After compensation is set, it should not require another adjustment.

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Figure 8.6

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Electro-Motive Model 567.645 & 710 Series Diesel Engines

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Governor Qualification

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Many governors are needlessly changed out because of the lack of proper troubleshooting procedures. Governor problems usually show up as engine speed variations such as hunting, surging or jiggle, but an engine showing signs of engine speed variation does not necessarily have a governor problem. Before changing a suspected governor, verify that the speed variation is not caused by one of the following conditions:

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Check the linkage between the governor and the fuel racks for binding or excessive backlash.

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Disconnect each injector from the injector control shaft by removing the pin from the adjusting link, then operate the injector rack in and out checking for binding or tight spots. Make sure all injectors are the proper type for the application.

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Check engine operation to be sure that all cylinders are firing properly.

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Check for bubbles in the return fuel sightglass. If evident, verify that the fuel system is functioning properly, using the checks in the fuel system troubleshooting section of this text.

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Check the setting of the governor compensation needle valve. Ensure that the load on the engine is not fluctuating and causing the engine RPM to respond to these changes. Items to check include the load regulator wiper arm to make sure the vane motor is not causing the load regulator to hunt, excitation circuit causing overexcitation of the main generator and ma1 function of protective device such as current overload relays.

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With the engine at maximum speed and full load, check the quadrant on the governor. If the rack dimension is shorter than the limit on the governor identification plate, the engine is either overloaded or lacking fuel.

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Check speed setting circuits for correct voltage levels and proper sequencing.

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Check the governor drive for any evidence of misalignment, roughness, or excessive backlash.

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Flush governor following the procedure outlined in this chapter. _

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ITS LocomotiveTraining Series -Student Text

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CHAPTER Protective Devices

Introduction There are many devices and systems on the locomotive designed to protect the locomotives mechanical and electrical systems. In this section we will focus on the main protective devices that protect the engine against;

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Low water, Crankcase Pressure HotOil LowOi1,and Engine Overspeed

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EPD ENGINE PROTECTION DEVICE

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Low Water & Crankcase Pressure Protection

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A low water detecting portion of the EPD,(Figure 9. l), balances water pressure against airbox pressure. When water pressure falls, the device dumps oil from the

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governor supply line, causing an engine shutdown.

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ITS Locomotive Training Series Student Text

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While there is no air box pressure when an engine is shut down, there is spring pressure. This spring pressure must be acted against by water pressure in order to keep the device latched in. On certain devices the static water pressure working against spring pressure will not keep the device latched in when the engine is shut down. This is not necessarily an indication that the device is defective. It is merely necessary to reset the device immediately after engine start.

Figure 9.1 EPD

Testing EPD Operation Operation of the low water shutdown device, Fig.9.2, should be checked at the intervals stated in the Scheduled Maintenance Program or whenever faulty operation is suspected.

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To test operation of the low water detecting device, run the engine at idle speed and turn the test cock mounted on the water pump discharge elbow to the horizontal position. The low water button should pop out smoothly without hesitation after water trapped behind he operating diaphragm escapes through the drain hole provided (in not mom than a fa0 seconds oftime). Return the test cock to the vertical position.

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Figure 9.2 Test Cock Operation

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Eiectro-MotiveModel 567.645 & 710 Series Diesel Engines

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Observe the low oil plunger on the governor as it moves out. The plunger should extend fully and the engine begin to shut down in about 5 5 seconds. As the engine begins to shut down reset the low water button and the low oil plunger. Operate the rack positioning lever to bring the engine back up to idle speed before complete shutdown. Verify that the low water button stays set. If the low water shutdown reset pushbutton does not pop out freely without assistance when the test cock is opened and the engine is at idle. the device should be removed and replaced with an operative device. Refer to the Service Data page for a listing of instructions covering maintenance and qualification of the low water protector. Special apparatus is required for proper testing. The crankcase pressure detector may be tested in a similar manner by applying a rubber tube over the test opening on top of the detector and applying suction to trip the upper button. The combination low water and crankcase pressure detector is a mechanically operated, pressure-sensitive device designed to determine abnormal conditions of engine coolant and crankcase pressures. The low water safety device is a spring loaded, normally open, two-way valve piloted by a latching mechanism on a diaphragm stack. There are two diaphragms in the stack; one sensing water pressure into the engine, and the other sensing engine air box pressure.

-NOTE:

The air box-to water diaphragm area ratio for TURBOCHARGED IS 1 :l.

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The air box-to water diaphragm area ratio for BLOWER (ROOTS)IS 3:l.

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Under normal operating conditions water pressure exceeds air box pressure.

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The low water reset button WILL TRIP when water pressure IS within 1/2 psi of air box pressure. The following conditions will cause the detecor to trip:

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Loss of water level.

Pump cavitation due to air entrainment (during sxrting).

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Pump cavitation due to water temperature apprcaching boiling point. Applicable to non-pressurized systems.

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Excessive air box pressure due to turbine surging at low throttle

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speeds. (Turbochargedengines only.)

OVERFILLING the water tank can cause low waTer shutdown.

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ITS LocomotiveTraining Series -Student Text

3. Air Box Pressure 4. Oil In From Governor 5. Trip Position 6. Latch Position 7. Oil Return To Crankcase 8. Vent Fitting 9. Crankcase Pressure

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Figure 9.3 Low Water Pressure Condition

In some installations, the test cock is locateu at the bottom of the device while, in others, it is in the water pump outlet elbow. By rotating the test cock handle as illustrated in Figure 9.2, to the horizontal position, the discharge of water from the small orifice hole in the cock should be a steady flow. Because of contaminants in the cooling water, the small orifice in the cock may become plugged, reducing or restricting the bleed off of water pressure on the water diaphragm. In most cases, rapidly opening and closing the test cock a few times will dislodge the obstruction and allow the low water detector to trip. Plugging of the test cock in no way affects the operation of the low water device. With the engine running at idle speed, placing the test cock in the horizontal position, and obtaining a free flow of water from the orifice, should trip the device on the first or second try. If the device does not trip, the device should be taken off and checked on a test panel to determine the cause of malfunction. It is recommended that .”* ector be checked monthly. the operation of the lo *CI ”’4.X rb(

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ElectroMotive Model 567.645 & 710 Series Diesel Engines

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1. Water Pump Discharge Pressure 2. Water Pump Inlet Pressure 3. Alr Box Pressure 4. Oil In From Governor 5. Latch Position 6. Trip Position 7. Oil Return To Crankcase 8. Vent Fitting 9. Crankcase Pressure Positive

Figure 9.4 Positive Crankcase Pressure Condition

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Crankcase Pressure Detector (EMDEC)

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The crankcase pressure detector used on EMDEC equipped engines senses any malfunction which causes a positive, rather than the normally negative engine crankcase pressure. When the device senses a positive crankcase pressure, it trips a switch to signal the EMDEC master Electronic Control Module (ECM) which shuts the engine down.

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The EMDEC switch type crankcase pressure detector has a long stem held in a latched position until a positive pressure builds up in the crankcase. This pressure pushes on the large diaphragm which, in moving, releases the long stem. Outward movement of the stem operates a lever to close contacts in a switch mechanism attached to the bottom of the detector. This switch provides the shutdown signal to the ECM. Negative pressure is normally maintained by the crankcase ventilating equipment. The following are sonqiitions (upgly to troth EMDEC and mechanical injector systems) that can cause a crankcase pressure detector to trip: Blocked oil separator or aspirator tube in the exhaust, excessive oil level in crankcase, resulting in blockage of oil separator. Cylinder compression leak into the oil pan or top deck from a cracked cylinder head, cracked piston, loose injector, improperly installed or broken rings, broken valves or badly worn valve guides. I

ITS Locomotive Training Series - Student Text

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Pressurized air from the air box leaking to the crankcase from hardened or broken liner seals, broken crab bolts, loose crab bolt retainers or extreme cylinder scoring. Overheated part in crankcase igniting oil vapours (crankcase explosion). Incorrectly installed lube oil pressure relief valve, allowing oil splash to reach the diaphragm of the detector.

-WARNING: Following an engine shutdown caused by the tripping of a conventional or EMDEC crankcase pressure detector, DO NOT open any handhole or top deck covers to make an inspection until the engine has been stopped and allowed to cool for at least 2 hours. DO NOT attempt to restart the engine until the cause of trip has been determined. The action of the pressure detector indicates the possibility of a condition within the engine, such as an overheated bearing, that may ignite the oil vapours with an explosive force, if air is allowed to enter the engine. If the crankcase pressure detector cannot be reset, DO NOT operate the engine until the pressure detector has been replaced, since the diaphragm backup plates may be damaged.

Figure 9.5 Crankcase Pressure Detector

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Electro-MotiveModel 567,645 & 710 Series Diesel Engines

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Hot Oil Detector A thermostatic valve located on the outlet elbow from the main lube oil pump is calibrated to open when lube oil temperature reaches nominally 260°F (126OC).At this temperature the probability exists that either the lube oil cooler is plugged on the water side, or steam pressure in the cooling system is preventing engine shutdown by the low water detector. When oil temperature causes the valve to open, pressure in the line to the oil pressure sensing device in the engine governor is dumped. The device sees low oil pressure and reacts to shut the engine down.

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Fig. 9.6 Hot Oil Detector Thermostatic Valve

and Location (Right)

The thermostatic valve is non latching, and it will reset automatically when oil temperature falls. The engine may then be restarted when the governor low oil plunger is reset. -WARNING: After it has been determined that hot oil is the cause for engine shutdown, make no further engineroom inspections until the engine has cooled sufficiently to preclude the possibility that hot oil vapor may ignite. When a low Oil shutdown occurs, always inspect for an adequate supply of water and oil before attempting to restart the engine. Also check engine water temperature. Do not add cold water to an overheated engine.

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ITS Locomotive Training Series -Student Text

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The hot oil detector should be removed from the engine and tested at intervals suggested in the applicable Scheduled Maintenance Program. Test the hot oil detector as follows: Connect a 50 psi (345 kPa) air line to the hot oil detector inlet port (port with arrow) Attach a return line to the outlet port to prevent creating oil spray when detector opens. Place detector in a 235" F ( 112.6'C) oil bath with a thermometer. Check for leaks between the body and cap. Increase the temperature of the oil bath to 258" F (12SoC),the valve should open. If not the detector should be replaced with a qualified unit, On locomotives equipped with EMDEC fuel injection, the Hot Oil Detector has been replaced with a Lube Oil Temperature sensor which reports the oil temperature to the computer.

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Low Lube Oil Shut Down

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The low lube shutdown system protects the engine in case of a failure of the mechanical support systems.

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"True" low lubricating oil pressure;

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"False" low lube pressure caused by a failure of the cooling system and detected by either of the low cooling water portion of the E.P.D. or hot oil detector;

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"False'' low lube pressure caused by the E.P.D. sensing a positive crankcase pressure (crankcase is normally under a slight vacuum);

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"False" low lube pressure caused by manual engagement of the system connected to a lube oil line from the engine on one side and speed setting oil pressure on the other side.

Should oil pressure in the line drop below the speed setting oil pressure, the system will take action to shut down the engine. When the engine is at idle, there is a mechanism that builds in a delay of 50 to 60 seconds. This delay is to allow oil pressure to build up when starting the engine. The delay is reduced in steps to the third throttle position. In the fourth position and higher there is no time delay in the shut down system.

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Electro-MotiveModel 567.645 & 710 Series Diesel Engines

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To shut the engine down, the system bleeds the speed setting oil from the top of the speed setting piston.

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LOW Oil Pressure Shutdown Plunger

The governor reacts by moving the layshaft and racks to the no fuel position, shutting down the engine.

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A switch is tripped setting off an alarm in the operators cabin, and a plunger protrudes from the side of the governor exposing a red band. The engine cannot be restarted until this plunger is reset.

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The hot oil detector and engine protective device both simulate a loss of oil pressure by bleeding oil pressure off of the line to the governor. Figure 9.7 Low Oil Shutdown Button

Engine Overspeed The engine overspeed trip is a mechanical safety device to stop fuel injection if engine speed exceeds specified limit. A flyweight mounted on counterweight at front of right bank camshaft activates the trip. ll centrifugal force exceeds adjustable spring tension, flyweight moves out. LATCHED msinoN TRIPPED POSrnON When the flyweight moves out, it contacts the trip pawl. Figure 9.8 Overspeed Trip The Trip pawl uses an actuating spring to move connecting links, which rotate a trip shaft on each bank of the engine. The trip shafts extend along each top deck behind thecylinder heads. Under each : injector rocker arm,-there is a pawl in contact with a small cam on the trip shaft. C T ~pt*) When the tri cam rotates upward, it raises a pawl under the rocker arm to prevent further actuation o the el injector.

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An external latch lever is located on the overspeed trip housing just above the accessory drive housing.

Trip speed is usually set at 10% in excess of normal engine full speed; 900 rpm units trip at 990 rpm.

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ITS Locomotive Training Series Student Text

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Figure 9.7 Overspeed Trip

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16-71OG limit has been revised to 1035-1050 rpm to prevent tripping system during locomotive transition.

Adjustment Determine trip speed using a hand tach applied to end of camshaft through access cover on RH front camshaft cover of trip housing. Run engine up until trip lever moves. NOTE If trip does not occur before 990 rpm (orotherwise specified maximum speed), do not exceed the 10% overspeed. The mechanism needs adjustment.

Shut engine down and remove large cover from right side of housing. Back-off spring tension by loosening locknut, then adjusting nut.

Note: Loosening spring tension decreases t i p speed. Secure nuts and restart engine. Again using hand tach, observe trip speed. Repeat as necessary to fall within specified range.

Note: Always make adjustments in tightening direction.

The minimum clearance between flyweight and pawl is .010".

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Electro-Motive Model 567,645 & 710 Series Diesel Engines

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SYSTEM BLOCK DIAGRAM "EMDEC" 16 Cylinder

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