Introduction

NOTE: For Specifications with illustrations, make reference to ENGINE SPECIFICATIONS FOR D342 INDUSTRIAL & MARINE ENGINES, Form No. REG01362. If the Specifications in Form No. REG01362 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

Fuel System

SCHEMATIC OF THE FUEL SYSTEM
1. Line for the return of fuel to the fuel tank or standpipe (if so equipped). 2. Fuel priming pump. 3. Fuel filter bypass valve. 4. Fuel filter. 5. Fuel injection pump. 6. Precombustion chamber. 7. Fuel supply line. 8. Primary fuel filter. 9. Fuel transfer pump. 10. Fuel transfer pump bypass valve. 11. Fuel manifold.

This engine has a pressure type fuel system. There is an injection pump and injection valve for each cylinder. The injection pumps are in the pump housing on the right side of the engine. The injection valves are in the precombustion chambers, in the cylinder heads.

Fuel for the fuel system comes from the fuel tank through supply line (7) to primary fuel filter (8). The fuel goes through the primary fuel filter and to the fuel transfer pump (9).

The transfer pump sends the fuel through a passage in the accessory drive housing and fuel filter housing to fuel filter (4). Fuel filter bypass valve (3) keeps the pressure of the fuel to approximately 27 psi (1.9 kg/cm²). Since the transfer pump (9) sends more fuel than is needed to keep the pressure of the fuel at approximately 27 psi (1.9 kg/cm²), the extra fuel returns to the fuel tank through line (1).

Fuel goes from the fuel filter to fuel manifold (11) in the pump housing. The fuel manifold is the source of fuel supply for the injection pumps. The injection pumps send fuel through lines to the injection valves. The injection valves change the fuel to the correct fuel characteristic (spray pattern) for good combustion in the cylinders.

Use priming pump (2) to put pressure in the fuel system when needed. The priming pump can also be used to remove air from the fuel system.

Fuel Injection Pump Operation

Injection pump plungers (3) and lifter assemblies (8) are lifted by cams on camshaft (9) and always make a full stroke. The force of springs (7) hold the lifter assemblies against the cams of the camshaft.

Fuel from fuel manifold (5) goes through inlet passage (2) in the barrel and into the chamber above pump plunger (3). During injection, the camshaft cam moves the pump plunger up in the barrel. This movement will close the inlet passage and the fuel will go through the fuel lines to the injection valves.

The amount of fuel sent to the injection valves is controlled by turning the pump plunger in the barrel. When the governor moves fuel rack (4), the fuel rack moves gear segment (6) that is fastened to the bottom of the pump plunger.

CROSS SECTION OF THE HOUSING FOR THE FUEL INJECTION PUMPS
1. Check valve. 2. Inlet passage in pump barrel. 3. Pump plunger. 4. Fuel rack. 5. Fuel manifold. 6. Gear segment. 7. Spring. 8. Lifter assembly. 9. Camshaft.

Fuel Injection Valve

CROSS SECTION OF THE PRECOMBUSTION CHAMBER AND FUEL INJECTION VALVE
1. Fuel injection line. 2. Nut. 3. Glow plug. 4. Body. 5. Nozzle assembly. 6. Precombustion chamber.

Fuel, under high pressure from the injection pumps, is sent through the fuel lines to the fuel injection valves. When the fuel under high pressure goes into the nozzle assembly, the check valve inside the nozzle opens and the fuel goes into the precombustion chamber. The injection valve changes the fuel to the correct fuel characteristics (spray pattern).

Mechanical Governor

The governor is in the housing for the accessory drive and governor. The governor control is connected to the control lever on the engine governor. The governor controls the amount of fuel needed to keep the engine at the desired rpm.

The governor has weights (8), which are driven by the engine. The force of the weights on retainer (3), bearing (7), and lever assembly (6), puts force against the force of governor spring assembly (2). These two forces move the rack (1) which controls the amount of fuel to the engine to keep the engine operating at a constant speed.

MECHANICAL GOVERNOR
1. Rack. 2. Governor spring assembly. 3. Retainer. 4. Bearing. 5. Cover. 6. Lever assembly. 7. Bearing. 8. Governor weights. 9. Tube.

The governor control, controls only the compression of governor spring assembly (2). Compression of the spring always pushes to give more fuel to the engine. The centrifugal force (rotation) of governor weights (8) is always pulling to get a reduction of fuel to the engine. When these two forces are in balance, the engine runs at the desired rpm (governed rpm).

When the load on the engine goes up, there is a reduction in the rpm of the engine and the rotation of governor weights (8) will get slower. (The governor weights will move toward each other). Governor spring assembly (2) moves rack (1) to give more fuel to the engine. Engine rpm goes up until the rotation of the governor weights is fast enough to be in balance with the force of the governor spring assembly.

When there is a reduction in the engine load, there will be an increase in the rpm of the engine and the rotation of the governor weights (8) will get faster. This will move retainer (3), bearing (7), and lever assembly (6), and puts more force against the governor spring assembly. There is now a reduction in the amount of fuel to the engine. Engine rpm goes down until the centrifugal force (rotation) of the governor weights is in balance with the force of the governor spring assembly. When these two forces are in balance, the engine will run at the desired rpm (governed rpm).

Oil from the engine gives lubrication to the governor. Oil from the bearing assembly for the accessory shaft goes to cover (5) through tube (9). A passage in the cover gives oil to bearing (4). The governor shaft has oil holes in it to give lubrication to the bearing in retainer (3). The other parts of the governor get lubrication from splash lubrication (oil thrown by other parts). Oil from the governor goes into the housing for the timing gear through an oil return hole in the front of the housing for the governor and accessory drive.

Timing Gears

The timing gears are at the front of the cylinder block. Their cover is the housing for the timing gears. The timing gears keep the rotation of the crankshaft, camshaft, and fuel injection pump and governor drive in the correct relation to each other. The timing gears are driven by the gear on the crankshaft.

TIMING GEARS
1. Gear for fuel injection pump and governor drive. 2. Large outer gear on camshaft. 3. Idler gear for water pump. 4. Gear for water pump. 5. Small inner gear on camshaft. 6. Gear on crankshaft. 7. Idler gear for oil pump drive. 8. Gear for oil pump drive.

The gear (6) on the crankshaft drives the large outer gear (2) on the camshaft. This gear drives the idler gear (3) which drives gear (4) for the water pump. The small inner gear (5) on the camshaft drives gear (1) for the fuel injection pump and governor. The gear (6) on the crankshaft also drives idler gear (7) which drives gear (8) for the oil pump drive.

Air Inlet And Exhaust System

AIR INLET AND EXHAUST SYSTEM
1. Exhaust manifold. 2. Inlet manifold. 3. Engine cylinder. 4. Turbocharger impeller. 5. Turbocharger turbine wheel. 6. Air inlet. 7. Exhaust outlet.

The air inlet and exhaust system components are: air cleaner, inlet manifold, cylinder head, valves and valve mechanism, exhaust manifold, turbocharger, and muffler.

The air cleaner cleans the air before it gets into the turbocharger and inlet manifold. The turbocharger gives air boost to the inlet air for the engine. Changes in load on the engine and the injection of fuel will cause a change in rpm of the turbocharger turbine wheel and impeller. When the load on the engine goes up, the rpm of the turbocharger will increase to give more air to the engine.

Valves And Valve Mechanism

The valves and valve mechanism control the flow of air and exhaust gases in the cylinder during engine operation.

The intake and exhaust valves are opened and closed by movement of these components; crankshaft, camshaft, valve lifters (cam followers), push rods, rocker arms, and valve springs. Rotation of the crankshaft causes rotation of the camshaft. The camshaft gear is driven by, and timed to, a gear on the front of the crankshaft. When the camshaft turns, the cams on the camshaft also turn and cause the valve lifters (cam followers) to go up and down. This movement makes the push rods move the rocker arms. The movement of the rocker arms will make the intake and exhaust valves in the cylinder head to open and close according to the firing order (injection sequence) of the engine. Two valve springs for each valve help to hold the valves in the closed position.

Valve rotators cause the valves to have rotation while the engine is running. This rotation of the valves keeps the deposit of carbon on the valves to a minimum and gives the valves longer service life.

VALVES AND VALVE MECHANISM
1. Push rod. 2. Rocker arm. 3. Sleeve. 4. Retainer. 5. Outer spring. 6. Inner spring. 7. Valve rotator. 8. Valve bushing (valve guide). 9. Insert. 10. Guide for valve lifter. 11. Valve. 12. Yoke. 13. Valve lifter (cam follower).

Turbocharger

The turbocharger is installed at the rear of the exhaust manifold. All the exhaust gases from the engine go through the turbocharger.

The exhaust gases go through the blades of the turbine wheel. This causes the turbine wheel and compressor wheel to turn.

Clean inlet air from the air cleaner is pulled through the air inlet of the compressor housing by the turning compressor wheel. The compressor wheel causes a compression of the air. The air then goes to the inlet manifold of the engine.

When the load on the engine goes up, more fuel is put into the engine. This makes more exhaust gases and will cause the turbine and compressor wheels of the turbocharger to turn faster. As the turbocharger turns faster it gives more inlet air and makes it possible for the engine to burn more fuel and will give the engine more power.

Maximum rpm of the turbocharger is controlled by the rack setting, the high idle speed setting, and the "altitude" (height above sea level) at which the engine is operated.

Show/hide table

If the rack setting or the high idle speed is higher than the setting in the book RACK SETTING INFORMATION for the "altitude" (height above sea level) at which the engine is operated, there can be damage to the engine or to parts of the turbocharger.

CROSS SECTION OF TURBOCHARGER
1. Compressor housing. 2. Thrust bearing. 3. Lubrication inlet port. 4. Turbine housing. 5. Compressor wheel. 6. Exhaust outlet. 7. Air inlet. 8. Bearing. 9. Lubrication outlet port. 10. Bearing. 11. Turbine wheel.

The bearings for the turbocharger use engine oil under pressure for lubrication. The oil comes in through the oil inlet port and goes through passages in the center section for lubrication of the bearings. Oil from the turbocharger goes out through the oil outlet port in the bottom of the center section and returns to the engine lubrication system.

The adjustment of the fuel rack is done at the factory for a specific engine application. The turbocharger and governor housing are sealed to prevent changes in the adjustment of the rack setting and the high idle speed.

Lubrication System

LUBRICATION SYSTEM
1. Oil supply line for turbocharger. 2. Rocker arm shaft. 3. Oil tube from oil manifold to rear rocker arm shaft (similar tube to front rocker arm shaft). 4. Tube for oil pressure gauge. 5. Oil return line from turbocharger. 6. Oil filters (two). 7. Oil filter base. 8. Oil manifold. 9. Tube. 10. Passage to main bearing. 11. Tube from oil cooler. 12. Tube to oil cooler. 13. Tube from oil filter base to housing for fuel injection pumps. 14. Passage in connecting rod. 15. Rear scavenger suction bell. 16. Passage in crankshaft. 17. Passage from oil pump to oil filter base. 18. Oil pump (three section). 19. Oil pump drive shaft. 20. Front scavenger suction bell.

Flow Of Oil Through The Engine (Normal Operation)

The lubrication system uses a three section oil pump (18). The oil pump is in the oil pan and is driven by drive shaft (19) from the engine gears. Oil returns to the center of the oil pan through suction bells (15 and 20).

Oil is sent from the oil pan by the oil pump (18) through passage (17) to oil filter base (7). Oil from the oil filter base goes through tube (12) to the oil cooler, (on the left side of the engine). Oil goes through the oil cooler from front to rear and returns to the filter base through tube (11). From the oil filter base the oil goes through the oil filters (6) and to the oil manifold (8).

A turbocharger lubrication valve, oil cooler bypass valve, and oil filter bypass valve are in the oil filter base. See the subject, FLOW OF OIL THROUGH THE OIL COOLER AND OIL FILTERS.

Oil is sent from the oil manifold through tube (9) and passages (10) to each main bearing for the crankshaft.

Passages (16) send oil from the main bearings to the bearings for the connecting rods. Passages (14) in the connecting rods give lubrication for the piston pins and for the cooling of the piston.

A tube from the oil manifold gives oil to the timing gears. See the subject, LUBRICATION FOR THE TIMING GEARS.

Inside passages and tubes (3) send oil from the oil manifold to rocker arm shaft (2). This oil gives lubrication to the rocker arms, valve bushings (guides), push rods, and valve lifters (cam followers). Tube (13) sends oil to the housing for the fuel injection pumps. Tube (4) sends oil to the gauge for the oil pressure.

The bearings for the camshaft get oil by splash lubrication (oil thrown by other parts).

After the oil has given lubrication to the engine, it returns to the engine oil pan.

Flow Of Oil Through The Oil Cooler And Oil Filters

Oil filter bypass valve (7), oil cooler bypass valve (8), and turbocharger lubrication valve (3) are in the oil filter base.

When the oil is cold (when the engine is first started), the bypass valve for the oil cooler will open. Oil from the oil pump is sent through the opened bypass valve for the oil cooler to the oil filters (1). Oil goes through the oil filters and on to passage (6) to the oil manifold to give lubrication to the engine.

FLOW OF OIL (COLD OIL)
1. Oil filters (two). 2. Oil supply line for turbocharger. 3. Turbocharger lubrication valve. 4. Oil filter base. 5. Oil cooler. 6. Passage to oil manifold. 7. Oil filter bypass valve. 8. Oil cooler bypass valve.

As the temperature of the oil goes up, the bypass valve for the oil cooler will close and the oil will go through oil cooler (5) and then to the oil filters.

When the engine is started, the lubrication valve for the turbocharger will be open. The oil from the oil pump goes through line (2) to the turbocharger.

As the pressure of the oil through the oil filters goes up, the lubrication valve for the turbocharger will close and the oil will go through the oil filters and then to the turbocharger.

FLOW OF OIL (NORMAL OPERATION)
1. Oil filters (two). 2. Oil supply line for turbocharger. 3. Turbocharger lubrication valve. 4. Oil filter base. 5. Oil cooler. 6. Passage to oil manifold. 7. Oil filter bypass valve. 8. Oil cooler bypass valve.

The bypass valve for the oil filters will open if the oil filters have a restriction. This allows the oil to go from the oil pump directly to passage (6). Only clean oil goes to the engine, unless the filters have a restriction or the viscosity of the oil is too high.

The bypass valves (7 and 8) makes it possible for the engine to have lubrication if the oil filters, oil cooler, or both the oil filters and oil cooler have a restriction.

Lubrication For The Timing Gears

TIMING GEAR LUBRICATION
1. Oil passage to bearing for accessory drive shaft. 2. Oil tube to bearing for camshaft. 3. Oil tube to passage (4). 4. Oil passage to bearing for water pump idler shaft. 5. Oil tube to water pump gear. 6. Bearing for accessory shaft. 7. Bearing for water pump idler shaft. 8. Passage in block. 9. Tube from oil passage in front of block. 10. Front bearing for camshaft. 11. Fitting. 12. Supply tube from oil manifold. 13. Front bearing for crankshaft. 14. Passage to front bearing for crankshaft.

Oil under pressure comes from the oil manifold through tube (12) to passage (14), to the front bearing for the crankshaft (13), and to fitting (11).

Oil goes through tubes (9 and 2) to passages (8 and 1) in the cylinder block and gives lubrication to the bearing for the accessory shaft (6), the governor, and the front bearing for the camshaft (10). Part of the oil goes through tube (3) and passage (4) to give lubrication to the bearing for water pump idler shaft (7). Tube (5) sends oil to the drive gear for the water pump.

Cooling Systems

Radiator Cooled System

FLOW OF COOLANT IN RADIATOR COOLING SYSTEM
1. Cylinder head. 2. Water manifold. 3. Radiator inlet line. 4. Radiator cap. 5. Radiator. 6. Temperature regulators. 7. Bypass line. 8. Cylinder block. 9. Oil cooler. 10. Water pump. 11. Radiator outlet line.

Water pump (10) is gear driven by the engine timing gears. The water pump gets coolant from the bottom tank of radiator (5) and sends some of the coolant into cylinder block (8). The remainder of the coolant goes through oil cooler (9), to cool the oil for lubrication of the engine, and into the cylinder block.

The coolant then goes around the cylinder block, around the cylinder liners and up through the water ferrules and directors into cylinder head (1).

Coolant moves through the cylinder head and into water manifold (2). The coolant goes through the water manifold to temperature regulators (6) at the front of the water manifold. If the coolant is cold (cool), the temperature regulators will be closed. The coolant will go through bypass line (7) to the water pump. If the coolant is warm, the temperature regulators will be open and the coolant will go through line (3) and into the top tank of the radiator. Coolant then goes through the core of the radiator to the bottom tank, where it is again sent through the cooling system. A small part of the coolant goes through bypass line (7) when the temperature regulators are open.

Radiator cap (4) is used to keep the correct pressure in the cooling system. This pressure keeps a constant supply of coolant to the water pump. If this pressure goes too high, a valve in the radiator cap moves (opens) to get a reduction of pressure. When the correct pressure is in the cooling system, the valve in the radiator cap moves down (to the closed position).

Heat Exchanger Cooled System

FLOW OF COOLANT IN HEAT EXCHANGER COOLED SYSTEM
1. Cylinder head. 2. Water manifold. 3. Coolant outlet line. 4. Expansion tank. 5. Heat exchanger. 6. Outlet line for sea water. 7. Temperature regulators. 8. Sea water pump. 9. Cylinder block. 10. Oil cooler. 11. Water pump. 12. Bypass line.

Water pump (11) is gear driven by the engine timing gears. The water pump gets coolant from expansion tank (4) and sends some of the coolant into cylinder block (9). The remainder of the coolant goes through oil cooler (10), to cool the oil for lubrication of the engine, and into the cylinder block.

The coolant then goes around the cylinder block, around the cylinder liners and up through the water ferrules and directors into cylinder head (1).

Coolant moves through the cylinder head and into water manifold (2). The coolant goes through the water manifold to temperature regulators (7) at the front of the water manifold. If the coolant is cold (cool), the temperature regulators will be closed. The coolant will go through bypass line (12) to the water pump. If the coolant is warm, the temperature regulators will be open and the coolant will go through line (3) and into heat exchanger (5). The coolant goes through the heat exchanger where it is cooled. The coolant goes from the heat exchanger to expansion tank (4) where it is again sent through the cooling system. A small part of the coolant goes through bypass line (12) when the temperature regulators are open.

Sea water pump (8) sends water to heat exchanger (5). This water cools the coolant for the engine by going around the coils in the heat exchanger and then out through line (6).

Heat Exchanger Cooled System (Marine Application)

FLOW OF COOLANT IN HEAT EXCHANGER COOLED SYSTEM (Marine Application)
1. Cylinder head. 2. Exhaust manifold. 3. Water manifold. 4. Coolant outlet line. 5. Expansion tank. 6. Heat exchanger. 7. Outlet line for sea water. 8. Marine gear oil cooler. 9. Temperature regulators. 10. Bypass line. 11. Sea water pump. 12. Cylinder block. 13. Engine oil cooler. 14. Water pump.

Water pump (14) is gear driven by the engine timing gears. The water pump gets coolant from expansion tank (5) and sends some of the coolant into cylinder block (12). The coolant goes around the cylinder block, around the cylinder liners and up through the water ferrules and directors into cylinder head (1).

The remainder of the coolant goes through engine oil cooler (13), to cool the oil for lubrication of the engine, and into the exhaust manifold (2). The coolant goes through the exhaust manifold and cylinder head to water manifold (3).

The coolant goes through the water manifold to temperature regulators (9) at the front of the water manifold. If the coolant is cold (cool), the temperature regulators will be closed. The coolant will go through bypass line (10) to the water pump. If the coolant is warm, the temperature regulators will be open and the coolant will go through line (4) to heat exchanger (6) where it is cooled. The coolant goes from the heat exchanger to expansion tank (5) where it is again sent through the cooling system. A small part of the coolant goes through bypass line (10) when the temperature regulators are open.

Sea water pump (11) sends water through marine gear oil cooler (8) and into heat exchanger (6). This water cools the coolant for the engine by going around the coils in the heat exchanger and then out through line (7).

Keel Cooled System

FLOW OF COOLANT IN KEEL COOLING SYSTEM
1. Cylinder head. 2. Exhaust manifold. 3. Water manifold. 4. Coolant outlet line. 5. Expansion tank. 6. Reduction gear oil cooler. 7. Temperature regulators. 8. Bypass line. 9. Keel cooler. 10. Cylinder block. 11. Engine oil cooler. 12. Water pump.

Water pump (12) is gear driven by the engine timing gears. The water pump gets coolant from expansion tank (5) and sends some of the coolant into cylinder block (10). The coolant goes around the cylinder block, around the cylinder liners and up through water ferrules and directors into cylinder head (1).

The remainder of the coolant goes through engine oil cooler (11), to cool the oil for lubrication of the engine, and into exhaust manifold (2). The coolant goes through the exhaust manifold and cylinder head to water manifold (3).

The coolant goes through the water manifold to temperature regulators (7) at the front of the water manifold. If the coolant is cold (cool), the temperature regulators will be closed. The coolant will go through bypass line (8) to the water pump. If the coolant is warm, the temperature regulators will be open and the coolant will go through line (4) to keel cooler (9). The coolant goes through the keel cooler where it is cooled to reduction gear oil cooler (6). The coolant goes through the reduction gear oil cooler to expansion tank (5) where it is again sent through the cooling system. A small part of the coolant goes through bypass line (8) when the temperature regulators are open.

Basic Block

Vibration Damper

Viscous Type Damper

The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that cause damage.

The damper is made of a weight (1) in a metal case (3). The small space (2) between the case and weight is filled with a thick fluid. The fluid permits the weight to move in the case to cause a reduction of vibrations of the crankshaft.

CROSS SECTION OF A TYPICAL VIBRATION DAMPER
1. Solid cast iron weight. 2. Space between weight and case. 3. Case.

Rubber Ring Type Damper

The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that cause damage.

The damper is made of a flywheel ring (1) connected to an inner hub (3) by a rubber ring (2). The rubber makes a flexible coupling between the flywheel ring and the inner hub.

CROSS SECTION OF A VIBRATION DAMPER
1. Flywheel ring. 2. Rubber ring. 3. Inner hub. 4. Bolt.

Electrical System

The electrical system has three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the battery are all common in each of the circuits.

The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output to keep the battery at full charge.

The starting circuit is in operation only when the start switch is activated.

The starting circuit can have a glow plug for each cylinder of the diesel engine. Glow plugs are small heating units in the precombustion chambers. Glow plugs aid ignition of the fuel when the engine is started in cold temperature.

The low amperage circuit and the charging circuit are both connected to the same side of the ammeter. The starting circuit connects to the opposite side of the ammeter.

System Components

Alternator (Motorola)

ALTERNATOR
1. Slip rings. 2. Fan. 3. Stator. 4. Rotor. 5. Brush assembly.

The alternator is a three phase, self rectifying charging unit. The alternator is driven from an auxiliary drive by two V type belts.

The alternator has three main parts: a "rotating" (turning, radial motion) rotor (4) which makes magnetic lines of force; a stationary stator (3) in which alternating current (AC) is made; and stationary rectifying diodes that change alternating current (AC) to direct current (DC).

The alternator field current goes through the brushes. The field current is 2 to 3 amperes. The rectifying diodes will send current from the alternator to the battery or load, but will not send current from the battery to the alternator.

Regulator (Motorola)

The voltage regulator is a transistorized electronic switch. It feels the voltage in the system at the switch for oil pressure and gives the necessary field current to keep the needed system voltage. The voltage regulator has two basic circuits, the load circuit and the control circuit.

The load circuit has a positive potential from the input lead of the regulator to the rotor (field) winding. The control circuit makes the load circuit go off and on at a rate that will give the needed charging voltage.

Alternator (Delco-Remy)

The alternator is a three phase, self rectifying charging unit. The regulator for the alternator is part of the alternator. The alternator is driven from an auxiliary drive by two V type belts.

5S9088 ALTERNATOR
1. Regulator. 2. Fan. 3. Roller bearing. 4. Rotor. 5. Stator windings. 6. Ball bearing.

The only part in the alternator which has movement is the rotor. The rotor is held in position by a ball bearing at the drive end and a roller bearing at the rectifier end.

The compartment for the regulator is sealed. The regulator controls the alternator output according to the needs of the battery and the other components in the electrical system.

Starting Motor

The starting motor is used to turn the engine flywheel fast enough to get the engine running.

STARTING MOTOR
1. Field. 2. Solenoid. 3. Clutch. 4. Pinion. 5. Commutator. 6. Brush assembly. 7. Armature.

The starting motor has a solenoid. When the start switch is activated, electricity from the electrical system will cause the solenoid to move the starter pinion to engage with the ring gear on the flywheel of the engine. The starter pinion will engage with the ring gear before the electric contacts in the solenoid close the circuit between the battery and the starting motor. When the start switch is released, the starter pinion will move away from the ring gear of the flywheel.

Solenoid

A solenoid is a magnetic switch that uses low current to close a high current circuit. The solenoid has an electromagnet with a core (6) which moves.

SCHEMATIC OF A SOLENOID
1. Coil. 2. Switch terminal. 3. Battery terminal. 4. Contacts. 5. Spring. 6. Core. 7. Component terminal.

There are contacts (4) on the end of core (6). The contacts are held in the open position by spring (5) that pushes core (6) from the magnetic center of coil (1). Low current will energize coil (1) and make a magnetic field. The magnetic field pulls core (6) to the center of coil (1) and the contacts close.

Circuit Breaker

The circuit breaker is a safety switch that opens the battery circuit if the current in the electrical system goes higher than the rating of the circuit breaker.

A heat activated metal disc with a contact point completes the electric circuit through the circuit breaker. If the current in the electrical system gets too high, it causes the metal disc to get hot. This heat causes a distortion of the metal disc which opens the contacts and breaks the circuit. A circuit breaker that is open can be reset after it cools. Push the reset button to close the contacts and reset the circuit breaker.

CIRCUIT BREAKER SCHEMATIC
1. Reset button. 2. Disc in open position. 3. Contacts. 4. Disc. 5. Battery circuit terminals.

Safety Controls

Safety Control Shutoff

A safety shutoff for "overspeed" (engine running too fast) and low oil pressure is available for industrial engines.

The safety control shutoff (1) is installed on the rear of the housing for the fuel injection pumps and is driven by the camshaft for the fuel injection pumps.

Oil pressure from the engine lubrication system is used to activate the safety shutoff. Line (2) sends oil to the water temperature shutoff control valve. Line (3) gives engine oil pressure to the safety shutoff.

SAFETY CONTROL SHUTOFF
1. Safety control shutoff. 2. Line (pressure oil connection to water temperature shutoff). 3. Line (pressure oil to safety shutoff). 4. Release cable. 5. Shutoff for fuel rack. 6. Reset plunger. 7. Lubrication oil drain line. 8. Emergency manual shutoff button.

The overspeed shutoff part of the control stops the engine mechanically if the engine runs too fast.

The emergency manual shutoff button (8) works with the overspeed shutoff and can be used to activated the shutoff in an emergency.

Shutoff control release cable (4) activates the shutoff (5) for the fuel rack.

Reset plunger (6) is used to put the controls in the normal operation position, after the engine has been stopped by the controls.

NOTE: It is not necessary to use reset plunger (6) after the engine has been stopped in a normal way.

The parts of the safety shutoff get lubrication from oil leakage around the oil pressure shutoff piston. Return oil goes through line (7).

Operation Of Controls

Low Oil Pressure and Water Temperature Shutoff

The oil pressure control will stop the engine if the pressure of the lubrication oil becomes too low for safe operation. If the temperature of the water gets too high, it will open a shutoff control valve and cause low pressure of the lubrication oil. This activates the shutoff control and will stop the engine.

In normal engine operation, engine lubrication oil goes through line (3). (See illustration of Safety Control Shutoff). This oil goes to cover (4) and against control piston (6).

SHUTOFF CONTROL (Cross Section, Front View; Normal Operation)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 4. Cover. 5. Guide. 6. Piston. 7. Spring. 8. Release rod.

One end of slide follower (2) is engaged with guide (5). The follower is free to have movement on slide follower shaft (3) in the housing and is activated by the movement of guide (5).

Worm shaft (1) is turned by the drive for the safety shutoff. The control will function any time the engine is running.

When the pressure of the engine oil is in the safe operating range, piston (6) is held against guide (5) putting spring (7) in compression and the slide follower (2) out of contact with worm shaft (1).

SHUTOFF CONTROL (Cross Section, Side View; Normal Operation)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 5. Guide. 8. Release rod. 9. Pin. 10. Release latch. 11. Spring.

When the pressure of the engine oil becomes lower than the pressure for safe operation, the pressure of oil on piston (6) is less and spring (7) will force guide (5) and piston (6) to the stop position. Slide follower (2) will turn on shaft (3) and contact worm shaft (1).

With slide follower (2) engaged with worm shaft (1), the slide follower will move the length of worm shaft (1). As the slide follower comes to the end of its movement, pin (9) on the follower will make contact with release latch (10). The release latch (10) will move and permit release rod (8) to be moved out by force of spring (11).

Release rod (8) moving out will cause the control lever for the rack shutoff to move toward the rear of the engine. As the control lever moves and rod connected to the lever assembly contacts the linkage for the fuel rack and moves the fuel rack to the CLOSED position, which will cause the engine to stop.

SHUTOFF CONTROL (Cross Section, Front View; Shutoff Operation Position)
1. Worm shaft. 2. Slide follower. 3. Slide follower shaft. 5. Guide. 6. Piston. 7. Spring. 8. Release rod.

SHUTOFF CONTROL (Cross Section, Side View; Shutoff Operation Position)
1. Worm shaft. 2. Slide follower. 8. Release rod. 9. Pin. 10. Release latch. 11. Spring.

Overspeed Shutoff

If there is an "overspeeding" (engine running too fast) condition, the overspeed shutoff control will activate the release rod and move the fuel rack to the CLOSED position, which will cause the engine to stop.

Overspeed carrier assembly (1) is driven by gears and the drive for the safety shutoff. The overspeed shutoff will function any time the engine is running. A rotating weight (2) in the carrier flange is held toward the center of the carrier shaft by an adjustment screw, spring, and nut.

OVERSPEED CONTROL
1. Carrier assembly. 2. Rotating weight. 3. Release latch. 4. Release rod.

When the engine rpm goes up, the force of the weight will have an increase. The weight moves out of the carrier flange. The weight will move out until the spring force (restriction of weight movement out) is the same as the force moving the weight out.

When the engine overspeeds, the weight will move out of the carrier flange and make contact with release latch (3). Release latch (3) will move and permit release rod (4) to be moved and move the fuel rack to the CLOSED position, which will cause the engine to stop.

Emergency Manual Shutoff Button

Emergency shutoff button (5) is only used to stop the engine when there is an emergency. Do not use the emergency shutoff button to stop the engine in normal operation. In normal operation, remove all of the load from the engine and make a reduction in engine rpm to low idle before the engine is stopped.

In an emergency where the engine must be stopped immediately, push the emergency shutoff button in and hold it until the rack has been moved to the CLOSED position.

EMERGENCY SHUTOFF
1. Weight. 2. Carrier assembly. 3. Pin. 4. Plunger. 5. Button.

When you push button (5) it will move plunger (4) against pin (3) which will force weight (1) out of carrier assembly (2), this makes the shutoff control operate the same as "overspeeding" (engine running too fast).

Setting The Control

If the engine has been stopped by the safety shutoff, the cause of the engine stopping must be found and corrected. After the problem has been corrected, put the controls in the normal operation position.

Setting After Overspeed and Emergency Manual Shutoff

Put the release rod in the normal operation position. Pull the rack shutoff lever on the governor housing, toward the front of the engine. The engine will now start.

Setting After Low Oil Pressure or Water Temperature Shutoff

Push reset plunger (4). This will move the piston (3) and pin against guide (1). The movement of the guide will turn slide follower (2) away from the end of the worm shaft. This will permit the spring to move the slide follower to the start of the threads on the worm shaft.

To put the release rod in the normal operation position. Pull the rack shutoff lever, on the governor housing, toward the front of the engine. The engine will now start.

SHUTOFF SETTING CONTROL
1. Guide. 2. Slide follower. 3. Piston. 4. Reset plunger. 5. Release rod.

NOTE: In cold weather operation, it can be necessary to push the reset plunger (4) when starting the engine to keep the shutoff control from activating. This is necessary because the oil pressure does not get to the operating range fast enough during the longer starting period needed in these conditions.

In normal weather operation, the pressure of the oil will get to the operating range before the slide follower (2) has moved to the length of the worm shaft and activated the release lever and rod.

Woodward UG-8 Governor

(For Electric Set Application When Frequency Control is Important)

There is no direct mechanical link between the weights and the fuel rack. Movement of the fuel rack is done by a hydraulic piston which is operated by action of the governor weights and a compensation piston.

WOODWARD UG-8 GOVERNOR
1. Synchronizing motor. 2. Synchronizer knob. 3. Speed droop knob. 4. Compensating pointer. 5. Synchronizer indicator. 6. Load limit knob. 7. Plug.

Engine rpm is controlled by changing the compression of the governor spring. An A.C. motor (1) installed on the top of the governor will permit remote control of the compression on the spring. A synchronizer knob (2) on the governor will control the same function (engine rpm). The synchronizer indicator (5) directly below the synchronizer knob, will give an indication of the number of revolutions of the synchronizer knob and the compression on the governor spring.

A speed droop knob (3) gives a way of changing the difference between FULL LOAD rpm and HIGH IDLE (with no load) rpm. Any difference between HIGH IDLE and FULL LOAD rpm is given the title of "DROOP" and this difference in rpm divided by the FULL LOAD rpm is the percent of droop. At zero droop the rpm is the same with a load as it is with no load. This droop control will permit the use of two or more generators to power a common load (in parallel). Only one of the paralleled electric sets (with zero droop) will feel the difference in the need of power and give the needed increase or decrease in power. The electric set or sets with high droop governors will control the constant load.

A load limit knob (6) is so the operator can have the ability to manually limit the engine rpm. This knob gives a positive stop to the movement of the linkage, and gives a way to rapidly stop the engine manually. The knob can also be used to make a reduction of engine speed to permit the engine to cool slowly. The engine can then be stopped by turning the knob to zero.

Compensating pointer (4) gives the exact degree of control to the governor adjustment. The information needed to make adjustments to the governor is in the TESTING AND ADJUSTING section of this book.

Remove plug (7) to get access to a needle valve adjustment screw. This screw will permit the operator to remove air from the hydraulic system for the governor. Loosening the screw will cause the hydraulic components to move rapidly and remove the air from the system. The adjustment of the needle valve will control the action of the governor.