Attachment_0001_NMWR_9-2815-220_Engine_(AVDS-1790).pdf

NMWR 9-2815-220

NATIONAL MAINTENANCE WORK REQUIREMENT (NMWR)

FOR

ENGINE WITH CONTAINER: TURBOSUPERCHARGED

DIESEL, FUEL INJECTION,

90-DEGREE “V” TYPE, AIR-COOLED,

12-CYLINDER, ASSEMBLY;

MODELS AVDS-1790-2CA

5705074 (2815-01-149-1313)

AVDS-1790-2DA

5705271 (2815-01-166-2051)

AND

AVDS-1790-2DR

5704489 (2815-00-124-5387)

DISTRIBUTION STATEMENT: Approved for public release; distribution is unlimited.

US Army Tank-automotive and Armaments Command, Warren, MI

CHANGE 1/16 SEPTEMBER 2005 19 NOVEMBER 2002

WARNING

The ignition units on this engine are capable of producing extremely high voltage. The output of this ignition system is sufficient to cause a dangerous electrical shock. Never touch any uncovered or live connections.

WARNING

Particles blown by compressed air are hazardous. Make certain air stream is directed away from user and that other persons are not exposed. Protect eyes and face with appropriate shields.

WARNING

Use goggles, rubber gloves, and rubber apron when cleaning parts in carbon removing compound. Provide adequate ventilation. Avoid inhalation of fumes and skin contact. If compound is splashed on skin, flush with fresh water and wash with alcohol. Alcohol containing 2 to 3 percent camphor is preferable.

WARNING

The fuel injection pump advance assembly will be hot following test.

Operator should wear gloves when removing unit from test stand.

WARNING

The penetrating power of atomized fuel under pressure is sufficient to puncture the skin and may cause blood poisoning. Keep hands away from nozzle during test.

WARNING

Solvents can burn easily, can give off harmful vapors, and are harmful to skin and clothing. Wear protective goggles and gloves and don’t breath vapors, to avoid injury or death, keep away from open fire and use in well ventilated area. If solvent gets on skin or clothing, wash immediately with soap and water.

WARNING

Air under pressure is used in the overhauling of this equipment. Serious injury may result when compressed air comes in contact with human skin or causes flying metal chips. Operating personnel and others in the immediate area should observe safety precautions. Wear safety glasses or goggles.

a

Compressed air used for cleaning purposes will not exceed 30 psi. Use only with effective chip guarding and personnel protective equipment (goggles/shield, gloves, etc.)

WARNING

Toxic gases from burning teflon items may produce serious injury. Do not discard by burning the teflon seal rings used in the overhaul of this equipment.

WARNING

Combustible material - close control of magnesium dust is necessary to prevent explosions and/or fire in such operations as brushing, sanding, grinding, etc.

Small particles of magnesium are readily combustible.

WARNING

(1) Penetrants may cause skin irritations to personnel if the skin is continually exposed to the penetrant.

(a) Observe the precautions recommended by manufacturers, or applicable MIL specifications.

(b) Wear neoprene gloves and keep the glove interiors clean.

(c) Wear protective apron.

(d) Keep penetrant off clothes.

(e) Wash penetrant from skin with soap and water.

(f) Wear a protective face mask to prevent inhaling dry developers.

(2) Replace broken or cracked filter lens immediately. Black lights, when maintained properly, are not injurious to the eyes or skin.

(3) Solvent-removed materials are flammable and burn freely. Do not store or use near fire or heat. Do not smoke while using such materials. Keep pressurized spray cans of penetrants away from heat and flame, even when empty.

(4) Penetrant materials will be used only in a well ventilated area.

b

CHANGE HEADQUARTERS

NO. 1 DEPARTMENT OF THE ARMY

WASHINGTON, D.C., 16 SEPTEMBER 2005

ENGINE WITH CONTAINER: TURBOSUPERSHARGED

DIESEL, FUEL INJECTION

90 DEGREES “V” TYPE AIRCOOLED,

12 CYLINDER, ASSEMBLY

MODELS AVDS-1790-2CA

5705074 (2815-01-149-1313)

AVDS-1790-2DA

5705271 (2815-01-166-2051)

AVDS-1790-2DR

5704489 (2815-00-124-5387)

DISTRIBUTION STATEMENT A – Approved for public release; distribution is unlimited.

NMWR 9-2815-220, 19 November 2002 is updated as follows:

1. File this sheet in front of the manual for reference.

2. This change is the result of the following:

3. New or updated text is indicated by a vertical bar in the outer margin of the page.

4. Added illustrations are indicated by a vertical bar adjacent to the figure number. Revised illustrations are indicated by a miniature pointing hand adjacent to the updated area and a vertical bar adjacent to the figure number.

5. Remove old pages and insert new pages as indicated below.

Remove Pages Insert Pages A/B Blank A/B Blank i – iv i – iv

WP 0001 00 – 0002 00 WP 0001 00 – 0002 00

WP 0005 00 – 0006 00 WP 0005 00 – 0006 00

WP 0011 00 – 0014 00 WP 0011 00 – 0014 00

WP 0016 00 WP 0016 00

WP 0019 00 WP 0019 00

WP 0024 00 – 0025 00 WP 0024 00 – 0025 00

WP 0027 00 – 0029 00 WP 0027 00 – 0029 00

WP 0032 00 – 0033 00 WP 0032 00 – 0033 00

WP 0037 00 WP 0037 00

Remove Pages Insert Pages

WP 0042 00 – 0045 00 WP 0042 00 – 0045 00

WP 0047 00 WP 0047 00

WP 0047 01 WP 0047 01

WP 0048 00 – 0053 00 WP 0048 – 0053 00

WP 0055 00 WP 0055 00

DA 2028 (Sample) DA 2028 (Sample)

DA 2028 (3) DA 2028 (3)

Metric Chart Metric Chart Front Cover Front Cover

This NMWR was prepared under the control of the Commanding General and the Equipment Publications Control Officer, TACOM, and is published for the information and guidance of all concerned.

OFFICIAL

PHILLIP B. OWENS

Official: Colonel, GS Chief of Staff

RONALD R. GEDYE

Publications Control Officer US Army TACOM T.00215

DISTRIBUTION: Special

INSERT LATEST UPDATED PAGES/ILLUSTRATIONS. DESTROY SUPERSEDED DATA.

A/B blank

LIST OF EFFECTIVE PAGES/ILLUSTRATIONS

Note: The portion of text affected by the changes are indicated by a vertical line in the outer margins of the page. Changes to Illustrations are indicated by miniature pointing hands. Changes to wiring diagrams are indicated by shaded areas.

Dates of issue for original and updated pages/work packages are:

Original 0 (19 November 2002) Change 1 (16 September 2005)

TOTAL NUMBER OF PAGES FOR FRONT AND REAR MATTER IS 36 AND TOTAL

NUMBER OF WORK PACKAGES IS 57 CONSISTING OF THE FOLLOWING:

Page/Illust *Change No. No.

Page/Illust *Change No. No

Page/Illust *Change No. No

Cover 1 Transmittal/Authentication 1 a – b 0 A/B blank 1 i – iv 1

WP 0001 00 – 0002 00 1

WP 0003 00 – 0004 00 0

WP 0005 00 – 0006 00 1

WP 0007 00 – 0010 00 0

WP 0011 00 – 0013 00 1

WP 0014 00 1

WP 0015 00 0

WP 0016 00 1

WP 0017 00 – 0018 00 0

WP 0019 00 1

WP 0021 00 – 0023 00 0

WP 0024 00 – 0025 00 1

WP 0026 00 0

WP 0027 00 – 0029 00 1

WP 0030 00 – 0031 00 0

WP 0032 00 – 0033 00 1

WP 0034 00 – 0036 00 0

WP 0037 00 1

WP 0038 00 – 0041 00 0

WP 0042 00 – 0045 00 1

WP 0046 00 0

WP 0047 00 1

WP 0047 01 1

WP 0048 00 – 0053 00 1

WP 0054 00 0

WP 0055 00 1

WP 0056 00 0

Glossary 1 – Glossary 4 1 Index 1 – Index 10 0 DA Form 2028 Sample/Reverse 1 DA Form 2028/Reverse (3) 1 Metric Chart 1 Back Cover 1 *Zero in this column indicates an original page i Change 1 ria.army.mil lp improve this publication. If you find any mistakes or if you know of a way to improve the procedures, please let us know. Submit DA Form 2028 (Recommended Changes to Equipment Technical Publications), through the Internet, on the Army Electronic Product Support (AEPS) website. The internet address is https://aeps. .

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TABLE OF CONTENTS – CONTINUED

WP Sequence No.

CHAPTER 3. MAINTENANCE INSTRUCTIONS

General Maintenance Instructions .................................................... 0005 00 Crankcase Assembly Overhaul ........................................................ 0006 00 Transmission Adapter, Engine Lifting Eye, and Installation Guides ..... 0007 00 Crankshaft and Associated Parts Overhaul....................................... 0008 00 Generator Drive Assembly Overhaul ................................................ 0009 00 Starter Drive Assembly Overhaul ..................................................... 0010 00 Piston and Connecting Rod Assembly Overhaul ............................... 0011 00 Cylinder Assembly Overhaul............................................................ 0012 00 Oil Pump Assembly Overhaul .......................................................... 0013 00 Oil Pan Assembly Overhaul ............................................................. 0014 00 Crankshaft Damper and Oil Filter Housing Overhaul.......................... 0015 00 Camshaft and Drive Assemblies Overhaul........................................ 0016 00 Front Fan Drive Assembly Overhaul................................................. 0017 00 Accessory Drive Housing and Rear Fan Drive Assembly Overhaul..... 0018 00 Automatic Injection Advance Assembly Overhaul.............................. 0019 00 Fan Drive Clutch Assembly Overhaul ............................................... 0020 00 Oil Coolers, Oil Cooler Screens, and Associated Parts Overhaul........ 0021 00 Oil Sampling System and Associated Parts Overhaul ........................ 0022 00 Oil Cooler Frames, Shrouds, and Associated Parts Overhaul............. 0023 00 Throttle Control and Associated Parts, Model AVDS 1790-2DR Overhaul ...................................................................................... 0024 00 Engine Shrouds, Air Deflectors, and Cooling Fans, Vanes, and Housing Overhaul........................................................ 0025 00 Intake Manifolds, Connecting Tubes, Turbosupercharger Support, and Associated Parts Overhaul ...................................................... 0026 00 Induction Heater System Overhaul................................................... 0027 00 Exhaust Manifolds Overhaul ............................................................ 0028 00 Cylinder Oil Drain Tubes Overhaul ................................................... 0029 00 Oil Filler and Indicator Tubes Overhaul............................................. 0030 00 Engine Generator and Starter Supports Overhaul ............................. 0031 00 Fuel Backflow Valve and Fuel Filters Overhaul ................................. 0032 00 Fuel Injection Tubes and Fuel Return Tubes Overhaul ...................... 0033 00 Smoke Generating System Overhaul................................................ 0034 00 Dust Detector and Associated Parts Overhaul................................... 0035 00 Dust Ejector and Associated Parts Overhaul..................................... 0036 00 ii Change 1

TABLE OF CONTENTS – CONTINUED

WP Sequence No.

Oil Hoses-Injection Pump, Turbosuperchargers, Oil Coolers, and Generator Overhaul....................................................................... 0037 00 Generator Air Ducting Overhaul ....................................................... 0038 00 Breather Tubes and Fire Extinguisher Tube Overhaul ....................... 0039 00 Fuel Injection Pump Drive Coupling Overhaul ................................... 0040 00 Power Take-Off Drive Assembly and Fuel Pump Drive Overhaul........ 0041 00 Engine Electrical Components Overhaul........................................... 0042 00 Engine Wiring Harness Brackets, Straps, and Associated Parts Overhaul............................................................. 0043 00 Engine Shipping and Storage Overhaul ............................................ 0044 00 Facilities......................................................................................... 0045 00 Depot Mobilization Requirements..................................................... 0046 00 Final Assembly and Testing............................................................. 0047 00 Final Inspection Record (FIR)…………………………………………….. 0047 01 Quality Assurance/Quality Control (QA/QC) Requirements ................ 0048 00

CHAPTER 4. SUPPORTING INFORMATION

References..................................................................................... 0049 00 Expendable and Durable Items List.................................................. 0050 00 Tool Identification List ..................................................................... 0051 00 Mandatory Replacement Parts......................................................... 0052 00 Support Items ................................................................................. 0053 00 Fabricated Tools List....................................................................... 0054 00 Index of Overhaul Inspection Procedures (OIPs)............................... 0055 00 Man-Hour Standards ....................................................................... 0056 00

GLOSSARY

INDEX

iii Change 1

HOW TO USE THIS MANUAL

MANUAL CONTENT

Overview

The front matter in this manual consists of general warnings, title block page, and table of contents.

The information contained in this manual is presented in four chapters. Each chapter is divided into Work Packages (WPs) that cover general information, troubleshooting procedures, maintenance procedures, and other information for specific systems or components. Each WP starts on a right hand page. Page numbers consist of the WP number followed by a dash and another number. For example “0014 00-7” means WP 0014 00, page 7.

At the end of this manual are an alphabetical index, DA Form 2028, and metric conversion chart.

Chapters

Chapter 1 provides general information, equipment description, and theory of operation.

Chapter 2 provides the preshop inspection.

Chapter 3 provides maintenance instructions.

Chapter 4 provides supporting information, consisting of references, expendable and durable items list, tool identification list, mandatory replacement parts, and wear limits, fits, and tolerances.

Alphabetical Index

An index is located after the last WP in this manual that provides an alphabetical listing of information and components/assemblies contained in this manual.

Warnings, Cautions, and Notes

You must read and understand this manual BEFORE performing overhaul of the AVDS-1790-2 series engine assemblies.

Throughout this manual you will see WARNING, CAUTION, and NOTE headings. There are good reasons for every one of these notices:

WARNING

A warning is used to alert the user to hazardous operating and maintenance procedures, practices, or conditions that could result in injury or death. Warnings must be strictly observed.

CAUTION

A caution is used to alert the user to hazardous operating and maintenance procedures, practices, or conditions that could result in damage to, or destruction of, equipment or mission.

NOTE

A note highlights an essential operating or maintenance procedure, condition, or statement.

Warnings and cautions appear immediately preceding the step to which they pertain. It is important to read and thoroughly understand the warnings and/or cautions before beginning maintenance. Notes may precede or follow the steps to which they pertain, depending on what makes the most sense.

Initial Setups

Before starting a task, you must obtain all the tools, supplies, and personnel listed in the initial setup. Be sure to read the task before performing the maintenance. If any other tasks are referenced, you must go to the initial setup page for each of those tasks to find out what tools, supplies, and personnel will be needed.

iv Change 1

GENERAL INFORMATION 0001 00

SCOPE

1. These instructions are for use by National Maintenance Management (NMM) Repair Site. They apply to the overhaul of engine Models AVDS-1790-2CA (Figures 1 and 2), AVDS-1790-2DA (Figures 2 and 3), and AVDS-1790-2DR (Figures 4 and 5). In case of conflict, these procedures take precedence over all other documents pertinent to engine overhaul and inspection.

Figure 1. Model AVDS-1790-2CA Engine, Right Front View.

0001 00-1 Change 1

GENERAL INFORMATION—Continued 0001 00

SCOPE - Continued

Figure 2. Model AVDS-1790-2CA or AVDS-1790-2DA Engine, Left Rear View.

Figure 3. Model AVDS-1790-2DA Engine, Right Front View.

0001 00-2 Change 1

SCOPE - Continued

Figure 4. Model AVDS-1790-2DR Engine, Right Front View.

Figure 5. Model AVDS-1790-2DR Engine, Left Rear View.

0001 00-3 Change 1

0001 00-4 Change 1

9-2815-220

SCOPE – Continued

2. This NMWR establishes requirements for removal, disassembly, cleaning, inspection, repair, assembly, lubrication, testing, final acceptance, shipment, and storage of the engine. To prevent the unnecessary disassembly or disposal of serviceable engine components, the following Reliability Centered Maintenance requirements must be considered:

a. The Army Oil Analysis Program Results will be recorded in conjunction with preshop inspection, to provide historical data.

b. Preshop inspection and inshop analysis using inspections as well as diagnostic tests will be performed at the highest level of assembly.

c. All tolerances and measurements are required checks for reliability and safety. Tests are used to collect data for future use.

3. Tolerances and wear limits established herein are the minimum acceptable. Parts, components, assemblies, or subassemblies not meeting these requirements will be rejected and disposed of in accordance with appropriate regulation or by the supply provisions of the contract/work directive.

4. Deviations and Exceptions for National Maintenance Management (NMM) Repair Site. When any work segment as set forth in this National Maintenance Work Requirement cannot be accomplished, or can only be accomplished in a manner other than specified, prior approval of the procuring activity shall be obtained by immediately submitting to the contracting officer a written notice containing the following information:

a. Serial number (if applicable), part number, and NSN of affected equipment.

b. Work elements which will not be completed or which will not be accomplished exactly as specified herein.

c. Reason for nonaccomplishment or deviation.

d. Action taken to correct condition causing nonaccomplishment or need for deviation.

e. Data relative to availability of parts required, if applicable.

f. Estimated man-hours required for completion.

g. Instructions and inspection required to maintain the integrity of the end item because of such omission or deviation.

5. Deviations for National Maintenance Management (NMM) Repair Site. If any work segment, as set forth in this national maintenance work requirement, cannot be accomplished, the procedures outlined in DESCOM R 702-1 shall be followed.

MAINTENANCE FORMS, RECORDS AND REPORTS

Department of the Army forms and procedures used for equipment maintenance will be those prescribed by (as applicable) DA PAM 750-8, Army Maintenance Management System (TAMMS) Users Manual; DA PAM 738-751, Functional Users Manual for the Army Maintenance Management System— Aviation (TAMMS-A);

or AR 700-138, Army Logistics Readiness and Sustainability.

REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR)

If your equipment needs improvement, let us know. Send an EIR. You, the user, are the only one who can tell us what you don’t like about your equipment. Let us know why you don’t like the design or performance. Put it on an SF Form 368 (Product Quality Deficiency Report). Mail it to the address specified in PAM 750-8, Army Maintenance Management System (TAMMS) Users Manual or as specified by the acquiring activity. We will send you a reply.

NMWR

Change

0001 00-5 Change 1

STANDARDS

1. Quality of Materiel. Unless otherwise specified, parts and material used for repair or modification will comply with equipment drawings and specifications.

2. Man-Hour Standards.

a. A guide listing average time (man-hours) required for disassembly, overhaul, and assembly of an individual component or item is contained in WP 0056 00. The man-hour allowances listed are sufficient to permit the task to be accomplished properly by qualified personnel with proper tools and equipment.

b. Man-hour estimates of individual depot operations may vary for the following reasons:

(1) Skill and training of personnel.

(2) Experience attained from previous rebuild programs.

(3) Material handling and shop facilities.

(4) Efficiency of supply operations.

3. Safety, care, and handling requirements not applicable.

ENGINEERING CHANGE PROPOSALS

Engineering Change Proposals (ECPs) will be submitted using DD Form 1693 (Engineering Change Proposal [Short Form]). (Refer to ISO 9000, Quality Management Systems, for instructions.) Completed forms should be mailed directly to US Army Tank-Automotive and Armaments Command, AMSTA-DSA-CM-L, Warren, MI 48397-5000. A reply will be furnished to you.

DEVIATIONS AND EXCEPTIONS

Requests for deviations or exceptions to this National Maintenance Work Requirement (NMWR) should be mailed directly to US Army Tank-automotive and Armaments Command, AMSTA-DSA-CM-L, Warren, MI 48397-5000.

MOBILIZATION REQUIREMENTS

All requirements of this NMWR will be exempted or revised in the event of mobilization. Only those procedures necessary to return the engine to a serviceable condition will be performed.

COST CONSIDERATIONS

This work requirement shall be the basis for establishing the extent of overhaul while taking into consideration cost factors. A determination shall be made on all subassemblies/assemblies to replace worn or damaged components, which are available in supply, if acquisition cost is less than the cost to repair and restore to the NMWR standard. The cost to repair/restore any individual item with an established Maintenance Expenditure Limit (MEL) to the NMWR standard shall not exceed the MEL, unless a waiver has been approved in accordance with AMC-R 750-51. This requirement does not apply to items exempted from MEL in accordance with AMC-R 750-51.

REPAIR PARTS, SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT

1. Common Tools and Equipment.

For authorized common tools and equipment, refer to the Modified Table of Organization and Equipment (MTOE), CTA 50-970, Expendable/Durable Items (Except: Medical, Class V, Repair Parts, and Heraldic Item), or CTA 8-100, Army Medical Department Expendable/Durable Items, as applicable to your unit.

2. Special Tools, TMDE, and Support Equipment.

Special Tools, TMDE, and Support Equipment are listed in WP 0054 00, Tool Identification List.

3. Repair Parts.

Repair parts are listed and illustrated in TM 9-2815-220-34P, Unit, Direct Support, and General Support Maintenance Repair Parts and Special Tools Lists for Engine.

4. Expendable Supplies and Materials.

Refer to WP 0050 00, Expendable and Durable Items List, for items referenced in this NMWR that are used when overhauling the engine.

END OF WORK PACKAGE

0001 00-6

Change 1

CHAPTER 1

DESCRIPTION AND THEORY OF OPERATION

ENGINE ASSEMBLY

0002 00-1

EQUIPMENT DESCRIPTION AND DATA 0002 00

EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES

Engine Models AVDS-1790-2CA, AVDS-1790-2DA, and AVDS-1790-2DR are similar and all use the same major components. The main components consist of the crankcase, crankshaft, cylinders, pistons, connecting rods, camshafts, damper housing, turbosuperchargers, starter, fuel injection pump, and fuel supply pump.

LOCATION AND DESCRIPTION OF MAJOR COMPONENTS

1. Location of Engine Components.

a. Engine Ends. The ends of the engine will be called the damper end or front and flywheel end or rear.

b. Engine Sides. As viewed from the front end toward the rear, the side to the right will be called the right side and the side to the left will be called the left side. Beginning at the front, the right bank of cylinders is numbered 1R through 6R and the left bank of cylinders is numbered 1L through 6L.

c. Main Bearing Numbering. Starting from the front, the main bearings are numbered 1 through 7.

d. Component Numbering. The cylinders, pistons, connecting rods, and connecting rod bearings are numbered with their respective cylinder number locations.

2. General Description.

a. Cylinders. Models AVDS-1790-2CA, AVDS-1790-2DA, and AVDS-1790-2DR engines are 12-cylinder, 90°, V-type, 4-cycle, air-cooled, turbosupercharged, diesel engines The cylinder assemblies are individually replaceable units, with overhead valves and valve rocker assemblies in the head. The cylinders are arranged in two banks of six cylinders each. Each bank of cylinders has an overhead camshaft arrangement to actuate the valves of each cylinder.

b. Fuel System. The engines feature a fuel injection system and a turbosupercharged air induction system which obtains optimum engine performance. The fuel injection system has a fuel injection metering pump which supplies metered fuel to individual cylinders through fuel injector nozzles. The fuel supply pump assembly located at the front of the engine, draws fuel from the vehicle fuel tanks and delivers it to the fuel injection pump. A turbosupercharger assembly is located on each side of the engine at the rear. The turbosuperchargers are exhaust-gas driven and increase the air flow pressure entering the air intake manifolds.

c. Fuel Filtering System. The engines include an engine primary fuel filter and fuel/separator type secondary fuel filter. Both filters have top mounted bleeder valves for removal of air from the fuel system. Water is removed automatically by a constant bleed orifice in the primary fuel filter and by an automatic water drain in the fuel/water separator secondary fuel filter.

d. Engine Generator.

(1) Model AVDS-1790-2CA Engine Generator. The Model AVDS-1790-2CA engine is equipped with a 28 volt oil cooled dc generator capable of 650 ampere output over the engine’s operating range. This generator develops an alternating current which is rectified within the unit to produce a direct current at the output terminals.

EQUIPMENT DESCRIPTION AND DATA—Continued 0002 00

LOCATION AND DESCRIPTION OF MAJOR COMPONENTS - CONTINUED

(2) Models AVDS-1790-2DA and AVDS-1790-2DR Engine Generators. The Models AVDS-1790-2DA and AVDS-1790-2DR engines use a 28 volt air cooled dc generator capable of developing 300 ampere output. Cooling air is drawn from the crew compartment via an air intake tube by a blower mounted on the generator. The intake tube extends along the crankcase below the intake manifold on the right side of the engine. Exhaust air is conveyed from the generator by an air exhaust tube elbow connected to the rear of the engine shroud. Generator outlet air is exhausted through the engine’s rear cooling fan vane.

e. Engine Starter. The engines are equipped with a 24 volt solenoid operated starter. A low voltage sensing module is included to prevent starter operation with improperly charged batteries.

f. Engine Lubrication System. Engine lubrication is provided by a force feed system consisting of four circuits. These are the scavenge circuit, the main or pressure oil circuit, the leveling circuit, and the make up circuit. Each circuit is operated independently by a single oil pump consisting of four separate sections.

g. Engine Crankcase Breather System. The engine crankcase is vented by an enclosed breather system which is vented through the crankcase breather tube at the left turbosupercharger exhaust pipe.

h. Engine Manifold Heater System. The engines are equipped with two intake manifold heaters that are installed between the intake manifold elbows and the turbosuperchargers. The heaters, when operated, preheat air entering the cylinders to facilitate cold weather starting and idle operations.

NOTE

Smoke generating system will not produce smoke if the vehicle fuel is JP-8.

i. Smoke Generating System. The engine is equipped with a smoke generating system which can be used to spray vaporized diesel fuel, from the vehicle’s fuel tanks, directly into the engine exhaust system. This creates a dense smoke screen to conceal the vehicle’s location and movements.

3. Detailed Description.

a. Crankcase. The crankcase is a one-piece aluminum casting with forged aluminum main bearing caps.

The bearing caps function as an integral part of the crankcase. Each cap is secured on studs with four slotted nuts. Two thru studs clamp the main bearing cap in the tunnel slot of the crankcase. With this type of crankcase and bearing cap construction, uniform load distribution in the bearing area is obtained making possible uniform distribution of combustion forces over the entire crankcase.

b. Main Bearings. The seven replaceable main bearings are steelbacked, split type, having copper-lead alloy bearing surfaces. The center main bearing is double-flanged with bearing material to control crankshaft end play and thrust.

c. Crankshaft, Flywheel, and Damper. Details of the crankshaft, flywheel, and damper are shown in Figure 1.

The key numbers in parentheses below refer to Figure 1 unless otherwise indicated.

(1) Crankshaft Assembly. The crankshaft assembly (44) is a nitrided steel forging with seven main bearing journals and six crankpins. Each crankpin accommodates two opposing connecting rod assemblies (52). Flanges are provided on the crankshaft assembly for mounting the flywheel (13) on the rear end and crankshaft torsional vibration damper (51) on the front end. The crankshaft assembly and flywheel are both statically and dynamically balanced. The crankshaft torsional vibration damper is a precision viscous type and is replaceable only as an assembly.

(2) Bearing Journals. All crankpin and main bearing journals are hollow to reduce weight. Holes are drilled diagonally through each main bearing journal and extend through the crank cheek and crankpin to provide a direct passage for oil under pressure to the connecting rod assemblies (52) and crankshaft main bearings.

0002 00-2 Change 1

d. Connecting Rods and Bearings. The connecting rod assemblies (52, Figure 1) are tapered I-beam section steel forgings. A bronze-lined, steel-backed, split bushing type bearing is pressed into the piston pin end of the connecting rod assembly. The replaceable precision connecting rod bearings are the steel-backed, split type having copper-lead alloy bearing surfaces.

e. Pistons, Pins, and Rings. The pistons (53, Figure 1) are aluminum castings, cam ground, and tapered to provide an accurate fit in the cylinders at operating temperatures. The piston dome is machined to the shape of a conical section (toridal shape) so that it tapers into the open type combustion chamber. Each piston is fitted with four rings. The top ring groove is composed of a steel insert which is an intregal part of the piston. The three remaining ring grooves are machined into the aluminum piston. The upper three rings are compression rings and the bottom ring is an oil-control ring. The heavy walled, tubular, steel piston pins are full-floating in the piston and the connecting rod assembly (52, Figure 1). The piston pin is retained in the piston by retaining rings, one at each end of the piston pin, in the piston pin bore.

f. Cylinders and Valves. The key numbers in parentheses below refer to Figure 1 unless otherwise indicated.

(1) Cylinder Assembly. Each cylinder assembly is an individually replaceable unit that consists of a barrel, cooling fin muff, and a cylinder head. The cylinder barrel, dome and intake and exhaust port liners are steel. The aluminum cylinder head cooling fins are cast to the steel dome. The cooling fins for the barrel are machined into an aluminum muff and shrunk onto the steel barrel. After the cylinder barrel fins are machined, the head and barrel are electron beam welded to form a single unit. Valve guides and seats are shrunk into place in the head. The cylinder barrel is “choked” at the head end to provide a straight bore under running conditions.

(2) Cylinder Assembly Mounting. A mounting flange is machined on the cylinder barrel near the base to provide an attachment of the cylinder to the crankcase. The cylinder assembly is secured to the crankcase with studs and nuts. An outer extension of the cylinder head encloses a recess or rocker box, which houses the valves, valve springs, and related parts. The intake valve rocker arm assembly

(1) and the exhaust valve rocker arm assembly (2) are held in place by rocker shafts in the cylinder head valve rocker support cover.

(3) Camshaft Bearing. A camshaft bearing surface is provided in each cylinder. The camshaft bearing is bored with the cylinder head valve rocker support cover in place; therefore, the covers are not interchangeable and each must remain as a part of a specific cylinder assembly. Each cylinder has re-placeable camshaft bearings at the camshaft bore. Identifying numbers are used on cylinder and covers to prevent mismatching. Counterbores in the rocker box and rocker support covers accommodate the intercylinder rubber hoses and the steel flanges which enclose the camshaft between the cylinders.

(4) Valves. The stem of the intake valve (56) and exhaust valve (55), for each cylinder, extends into the rocker box. Three nested springs, compressed between two retainers, and secured to the valve stem by two coneshaped locks, hold each valve to its seat. Each exhaust valve has a positive valve rotator which also serves as the lower spring retainer. Valve clearance adjusting screws with flat swivel pusher pads are mounted on one end of the intake valve rocker arm assembly (1) and the exhaust valve rocker arm assembly (2).

(5) Rocker Arm Assemblies. The intake valve rocker arm assembly (1) and the exhaust valve rocker arm assembly (2) of forged steel with roller cam-followers are used. The rollers are hardened and honed to provide an extremely smooth and permanent contact surface. Hollow rocker arm shafts and drilled passages in the rocker arms convey oil to all moving parts.

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0002 00-4

EQUIPMENT DESCRIPTION AND DATA—Continued 0002 00

7 8

14AVDS 2CA

ENGINE

33 31

AVDS-1790-2DR

ENGINE

42 37

Figure 1. Engine Major Working Parts.

KEY to Figure 1:

1. Intake valve rocker arm assembly

2. Exhaust valve rocker arm assembly

3. Left camshaft assembly

4. Camshaft driven gear

5. Camshaft drive gearshaft

6. Camshaft drive shaft

7. Camshaft drive bevel gearshaft

8. Accessory drive gearshaft assembly

9. Fuel injection pump advance assembly

10. Right camshaft assembly

11. Transmission accessory drive gearshaft

12. Accessory drive gear

13. Flywheel (Models AVDS-1790-2CA and AVDS-1790-2DA)

14. Generator drive gearshaft (Model AVDS-1790-2CA)

15. Flywheel adapter (Model AVDS-1790-2DR)

16. Flywheel (Model AVDS-1790-2DR)

17. Generator drive gearshaft (Models AVDS-1790-2DA and AVDS-1790-2DR)

18. Generator idler gear

19. Oil pump driven gear

20. Level control oil pump driven impeller

21. Pressure oil pump driven impeller

22. Scavenge oil pump driven impeller

23. Make up oil pump driven impeller

24. Make up oil pump drive shaft

25. Oil pump driven impeller shaft

26. Make up oil pump drive impeller

27. Scavenge oil pump drive impeller

28. Pressure oil pump impeller drive shaft

29. Level control oil pump drive impeller

30. Oil pump drive gear

31. Starter idler gear

32. Starter driven gearshaft

33. Starter drive gear

34. Front fan drive shaft

35. Fan drive bevel gearshaft

36. Rear fan drive shaft

37. Fan driven gearshaft

38. Fuel injection pump drive gearshaft

39. Fuel injection pump driven shaft gear

40. Fan drive clutch assembly

41. Cooling fan adapter

42. Rear cooling fan assembly

43. Fan drive bevel gearshaft

44. Crankshaft assembly

45. Power take-off gearshaft (Model AVDS-1790-2DR)

46. Fuel pump drive gear (Model AVDS-1790-2DR)

47. Fuel pump driven gear (Model AVDS-1790-2DR)

48. Fuel pump drive idler gear (Model AVDS-1790-2DR)

49. Fuel pump drive coupling (Models AVDS-1790-2CA and AVDS-1790-2DA)

50. Fuel pump drive adapter (Models AVDS-1790-2CA and AVDS-1790-2DA)

51. Crankshaft torsional vibration damper

52. Connecting rod assembly

53. Piston

54. Front cooling fan assembly

55. Exhaust valve

56. Intake valve

0002 00-5 Change 1

g. Camshafts. The key numbers in parentheses below refer to Figure 1 unless otherwise indicated.

(1) Camshaft Assemblies. The left and right camshaft assemblies (3 and 10) are mounted, one on each bank, on the cylinders and operate the valve mechanism. The camshaft assemblies are hollow to provide oil passages for pressure lubrication to the valve parts and to permit deflection when the cylinders fire. Tubular molded rubber hoses enclose the camshafts between cylinders.

(2) Camshaft Drive. Each camshaft is driven by the accessory drive gear (12), accessory drive gearshaft assembly (8), camshaft drive bevel gearshaft (7), camshaft drive gearshaft (5), and camshaft driven gear (4) through an inclined quill type camshaft drive shaft (6). The drive shafts can be removed to permit separate rotation of the camshafts for engine timing. When camshafts are correctly positioned in relation to the crankshaft, the drive shafts have different number of splines on each end and this allows them to be inserted in the camshaft bevel gearshafts without disturbing relationship between camshafts and crankshaft.

h. Lubrication System. Figure 2 is a flow diagram showing operational details of the lubrication system.

(1) General. The main pressure oil pump draws oil from the pressure oil pump compartment in the oil pan. This compartment is fed by the scavenge oil pump which picks up oil from the front end of the oil pan and by oil which drains into the pressure compartment from the cover of the pressure pump com-partment and the reserve compartment. The pressurized oil is forced through the engine oil coolers and oil filter to the engine oil galleries, bearings, turbosuperchargers, fuel injection pump, and to the piston oil sprayer nozzles. These nozzles are located in the crankcase below each cylinder and provide a continuous oil spray to the pistons and cylinder walls. A pressure regulator valve, located on the right side of the crankshaft damper and oil filter housing, is influenced by the pressure in the main bearing oil gallery and returns the incoming excess unfiltered oil to the oil pan.

(2) Oil Pan. The oil pan is a one-piece aluminum alloy casting divided into a pressure oil pump compartment, oil reserve compartment, and the sump compartment at the front of the pan. Cored passages from each of the compartments terminate at a central outlet and permit draining all of the compartments from a single drainage point. A cored passage also permits draining the oil coolers and oil filter compartment directly without permitting any sludge to enter the oil pan. The oil pan is designed to maintain a constant oil level above the main pressure oil pump pickup tube in the pressure oil pump compartment during vehicle operation regardless of the angle at which the engine may be inclined.

(3) Oil Pump. The oil pump assembly consists of four sections combined into a single unit. The scavenge oil pump section of the unit picks up oil from the front end compartment of the oil pan and delivers it to the main pressure pump oil compartment. The main pressure oil pump section picks up oil from its respective compartment and supplies oil to the engine oil galleries, bearings, and to the piston oil sprayer nozzles. The level in the pressure pump compartment is maintained by a dual inlet leveling pump which returns any excess oil to the reserve compartment. Oil is pumped from the reserve compartment by two make up pumps in a single pump section. These pumps pick up oil from opposite corners of the reserve compartment and discharge it into the pressure pump compartment. The dual pump design insures return of oil from the reserve compartment under all operating conditions, cold oil, slope operation, etc.

(4) Oil Filters and Control Valves. The engine oil filters and the bypass valve are located in the crankshaft damper and oil filter housing at the front of the engine. All engine oil passes through the oil filters. The oil filter bypass valve opens at a differential pressure of 35.6 psi. The bypass valve permits oil to bypass the filters in the event that they become clogged.

0002 00-6 Change 1

(5) Oil Sampling System. The oil sampling system consists of two toggle valves connected to the oil cooling system permitting easily accessible sampling of the engine and transmission oil to determine the need for oil changes. This permits a more precise method of determining the frequency of oil changes. On the models AVDS-1790-2CA and AVDS-1790-2DA there are two valves mounted together on top of the right bank oil coolers, one valve for engine oil and one for transmission oil.

Engine model AVDS-1790-2DR has only one valve located on the filter housing cover on the front of the engine.

i. Fuel System. The fuel systems used on the AVDS-1790-2CA and AVDS-1790-2DA engines are identical.

Figure 3 is a schematic diagram of the main fuel system used on these engines. The fuel system used on the AVDS-1790-2DR engine is similar except for the differences in the fuel supply pump assembly drive and routing of fuel injection pump overflow fuel. Figure 4 is a schematic diagram of the main fuel system used on the AVDS-1790-2DR engine.

(1) Fuel Supply Pump Assembly (AVDS-1790-2CA and AVDS-1790-2DA). The engine driven vane type fuel supply pump assembly is used to supply fuel under pressure to the fuel injection pump. The fuel pump is crankshaft driven by the fuel pump drive adapter (50, Figure 1) and the fuel pump drive coupling (49, Figure 1) located at the front of the engine.

(2) Fuel Supply Pump Assembly (Model AVDS-1790-2DR). A right angle drive is provided on the drive housing for the vane type fuel supply pump assembly. The pump is similar to the one used on the other models except that it rotates counterclockwise. The drive housing is lubricated with oil externally routed from the engine main oil gallery on the left side of the crankcase.

Figure 2. Engine Oil Flow Control – Flow Diagram.

0002 00-7 Change 1

Figure 3. Main Fuel System – Schematic Diagram, Models AVDS-1790-2CA and AVDS-1790-2DA.

0002 00-8

Figure 4. Main Fuel System – Schematic Diagram, Model AVDS-1790-2DR.

0002 00-9 Change 1

(3) Fuel Injection Metering Pump. The fuel injection metering pump is located in the “V” of the engine between the fan drive housings, and supplies fuel under high pressure to each cylinder. The pump is driven at engine speed from the fan drive housing located at the rear of the engine. A fuel injection pump advance assembly (9, Figure 1) is incorporated in the accessory drive housing to automatically provide a gradual degree advance of injection timing during the engine speed range from idle to 1800 rpm.

(4) Fuel Injector Nozzles and Tubes. Twelve fuel injector nozzles (Figures 3 and 4), one per cylinder, are used to inject fuel into the combustion chambers. Twelve fuel injector tubes of equal length carry the fuel from the fuel injection pump to the nozzles. The nozzles on each cylinder bank are interconnected by fuel return lines to provide a path for the return of excess fuel.

(5) Fuel Purge System. A manually operated purge pump is provided in the vehicle operator’s compartment and is used to clear the engine main fuel system and flame heater system of air, and fill them with fuel. Most of the purged air is removed through bleeder valves located in the top of the primary fuel filter and the fuel/water separator filter. The rest of the air is forced through the main fuel tubes into the fuel return lines and on to the vehicle fuel tanks. Water is removed from the system by a constant bleed orifice in the primary fuel filter and an automatic water drain in the fuel/water separator filter.

(6) Fuel Filters. The replaceable element type primary fuel filter is mounted on the left front of the engine and is equipped with a constant bleed orifice and drain line which constantly removes a metered amount of fuel and returns it to the main fuel tank through the fuel injector nozzle drain lines. This continuous drain, from the bottom of the filter, removes water in the free state that has been filtered from the fuel by the primary fuel filter element. The replaceable element fuel/water separator type filter is mounted on the left front of the engine. Fuel from the vehicle fuel tank passes through the primary filter before entering the engine fuel pump. The pump delivers fuel to the fuel water separator filter and on to the fuel injection pump. Excess fuel provides pump cooling as it flows through the fuel injection pump hydraulic heads and is returned to the fuel tanks (Figures 3 and 4). The fuel water separator filter unit has three replaceable elements and contains a chamber for collecting water. The two outer elements are coalescer elements and will remove emulsified water that has passed through the primary filter. The center element is a fuel filter element. The water removed from the fuel is automatically drained from the filter housing. Two water sensing probes are located in the filter housing. When the water level reaches the upper probe, an electrical circuit is completed, a solenoid valve opens and allows the water to drain. The valve closes when the water level reaches the lower probe. A drain cock is installed so the fuel/water separator may be drained manually. The unit provides moisture-free and uncontaminated fuel to the injection pump. Both the primary filter and the fuel/water separator filter incorporate top mounted bleeder valves to assist in the removal of air from the fuel system.

(7) Fuel Cutoff Solenoid. An electrically operated fuel cutoff solenoid is mounted in the fuel injection pump. The solenoid is normally open. A switch in the vehicle driver’s compartment actuates the circuit to close the solenoid. Closing the solenoid cuts off fuel delivery from the fuel injection pump and stops the engine. A manually operated override shutoff is provided to permit stopping the engine in the event of an electrical failure.

(8) Fuel Return Backflow Valve. A fuel return backflow valve (Figures 3 and 4) is installed between the fuel injection pump fuel return outlet and the fuel return hose assembly. The valve prevents fuel flowing back to the injection pump when the fuel supply is closed.

0002 00-10 Change 1

j. Manifold Air Induction and Heater System. The manifold air induction and heater system is represented in flow diagram form in Figure 5.

(1) Turbosupercharger Assemblies. Exhaust gas driven turgosupercharger assemblies, one for each bank of cylinders, are mounted on each side of the engine, at the rear. The turbosuperchargers increase the pressure of the intake air thereby delivering a higher density air to the cylinders as compared with a nonsupercharged engine. The higher density air, with a proper fuel flow, increases engine power.

(2) Intake Manifold Heater. The intake manifold, which distributes induction air to each bank of cylinders, is equipped with an electrically operated flame type intake manifold heater. The heater is provided as an aid for cold weather starting and cold weather operations. Operation of the heater switch (in the vehicle operator’s compartment) energizes the manifold heater fuel solenoid valve, the heater ignition unit, and spark plug for each heater simultaneously. Fuel is hand pumped through the manifold heater fuel filter and fuel solenoid valve and sprayed into the intake manifold. The fuel is ignited by the spark plug and burns in the intake manifold as the engine is cranking, and the flame heats the incoming air.

This flame-heated air and the products of combustion are fed directly into the cylinders with little heat loss. This results in an immediate engine response and assures complete combustion at low engine rpm and at no-load operating conditions with low ambient temperature.

(3) Solenoid Valve. The manifold heater fuel inlet solenoid valve prevents fuel pumped by the fuel pump assembly from entering the air intake manifold heater unless the heater system is energized. A manifold heater fuel return check valve and solenoid valve are located at the rear of the engine. The solenoid valve is also energized (opened) when the ignition unit and heater spark plugs are energized to permit excess fuel to be returned to the fuel tanks. The main fuel backflow valve prevents back flow of the fuel when the purge pump in the driver’s compartment is actuated.

NOTE

Smoke generating system will not produce smoke if the vehicle fuel is JP-8.

k. Smoke Generating System. The smoke generating system, Figure 6 uses the engine fuel pump to supply diesel fuel, from the vehicle fuel tanks, to two solenoid valves mounted at the rear of the engine. When the solenoid valves are energized (opened) they allow diesel fuel to be sprayed into the engine exhaust system. The fuel vaporizes and exits together with the engine exhaust gases. The fuel vapor cools on contact with the ambient air and condenses to form a dense homogeneous smoke screen. The electrical power to energize the solenoid valves is supplied by the air cleaner blower motor circuit. This prevents accidental activation of the smoke generating system when the engine is not running.

l. Exhaust System and Turbosupercharger. The exhaust system consists of four manifolds, one for each group of three adjacent cylinders. The two exhaust manifolds on each cylinder bank are connected to the turbosupercharger on their respective side of the engine. Exhaust gases from each side of the engine enter a turbosupercharger and are forced around a turbine housing, radially inward, and through a nozzle ring toward the turbine wheel.