FUEL INJECTION VALVE IN PRECOMBUSTION CHAMBER
1. Fuel line assembly. 2. Seal. 3. Body. 4. Nut. 5. Seal. 6. Nozzle assembly. 7. Glow plug. 8. Precombustion chamber.
Fuel, under high pressure from the injection pumps, is transferred through the injection lines to the injection valves. As high pressure fuel enters the nozzle assembly, the check valve within the nozzle opens and permits the fuel to enter the precombustion chamber. The injection valve provides the proper spray pattern.
Fuel ratio control bolt (7) is connected by a slot in collar (3) and bolt (4) through the engine governor to the fuel injection pump rack. An air line from the engine inlet manifold supplies manifold pressure air to the chamber inside cover (5).
When the engine is accelerated, or the load on the engine increases, bolt (7) in collar (3) restricts the movement of the fuel rack until the turbocharged boost of air in the inlet manifold and inside the fuel ratio control cover (5) forces diaphragm (2) to compress spring (6). Compressing spring (6) moves bolt (7) which relieves the restriction from collar (3) and the fuel rack. This allows the fuel rack to increase the fuel as the turbocharged air pressure increases with the increase in engine rpm. The compressed force of spring (1) can be adjusted if it is necessary to correct the fuel-to-air ratio.
FUEL RATIO CONTROL-CROSS SECTION
1. Spring. 2. Diaphragm. 3. Collar. 4. Bolt. 5. Cover. 6. Spring. 7. Bolt.
The governor control is linked to the lever on the engine governor. The operation of the governor controls the amount of fuel necessary for the engine to maintain the selected engine rpm even when the load changes.
The hydra-mechanical governor has engine driven governor weights (12), governor spring (5), a hydraulic valve (13) and piston (14). The valve and piston are connected to rack (17) in the fuel injection pump housing. The engine lubricating oil pump supplies pressure oil through passage (16) and around sleeve (15) for the hydraulic operation of the governor. The accelerator pedal controls only the compression of governor spring (5). The compressed spring force always pushes to increase the supply of fuel to the engine while the centrifugal force of the engine driven governor weights are always pulling to decrease fuel to the engine. The governed rpm of the engine is when these two forces balance.
HYDRA-MECHANICAL GOVERNOR (Typical Example)
1. Collar. 2. Speed limiter plunger. 3. Lever assembly. 4. Seat. 5. Governor spring. 6. Thrust bearing. 7. Oil passage. 8. Drive gear (weight assembly). 9. Cylinder. 10. Bolt. 11. Spring seat. 12. Weights. 13. Valve. 14. Piston. 15. Sleeve. 16. Oil passage. 17. Fuel rack. The governor valve is shown in the position when the force of the weights and the force of the spring are balanced.
When engine load increases, engine rpm decreases and revolving weights (12) slow down. The weights move toward each other and allow governor spring (5) to move valve (13) forward. As valve (13) moves, an oil passage around valve (13) opens to pressure oil. Oil then flows through passage (7) and fills the chamber behind piston (14). The pressure forces the piston and rack forward, increasing the amount of fuel to the engine. Engine rpm increases until the revolving weights rotate fast enough to balance the force of the governor spring.
When engine load decreases, engine rpm increases, revolving weights (12) speed-up, and the toes on the weights move valve (13) rearward, allowing the oil behind piston (14) to flow through a drain passage opened at the rear of the piston. At the same time, the pressure oil between sleeve (15) and piston (14) forces the piston and rack rearward, decreasing the amount of fuel to the engine. Engine rpm decreases until the revolving weights balance the force of the governor spring.
When the engine is started, speed limiter plunger (2) restricts the movement of the governor control linkage. When operating oil pressure is reached, the plunger in the speed limiter retracts and the governor control can be moved to the HIGH IDLE position.
When the engine rpm is at LOW IDLE, a spring-loaded plunger within the lever assembly in the governor bears against the shoulder of the low idle adjusting screw. To stop the engine, the plunger must be forced past the shoulder on the adjusting screw.
Oil from the engine lubricating system lubricates the governor weight bearing. The various other parts are splash lubricated. The oil from the governor drains into the fuel injection pump housing.
FUEL INJECTION PUMP HOUSING AND PUMP CROSS SECTION
1. Fuel manifold. 2. Inlet port. 3. Check valve. 4. Gear segment. 5. Pump plunger. 6. Spring. 7. Fuel rack. 8. Lifter. 9. Camshaft.
The injection pump plungers and the lifters are lifted by lobes on the camshaft and always make a full stroke. The lifters are held against the cam lobes by springs.
The amount of fuel pumped each stroke is varied by turning the plunger in the barrel. Action of the governor moves the fuel rack which turns the pump gear segment on the bottom of the pump plunger.
FUEL SYSTEM SCHEMATIC
1. Fuel return to fuel tank or standpipe (if so equipped). 2. Fuel filter bypass valve. 3. Fuel filter. 4. Fuel injection pump. 5. Precombustion chamber. 6. Fuel supply line. 7. Primary fuel filter. 8. Fuel transfer pump. 9. Fuel transfer pump bypass valve. 10. Fuel injection pump housing fuel manifold.
The fuel system is a pressure type with a separate injection pump and injection valve for each cylinder. Fuel is injected into a precombustion chamber, not directly into the cylinder.
A transfer pump supplies fuel to the manifold from which the injection pumps get fuel. Before the fuel is delivered to the manifold, it may be filtered first by a primary filter attachment which removes dirt particles, and is filtered by a final filter which removes more minute particles.
The transfer pump can supply more fuel than is required for injection, so a bypass valve is used to limit the maximum pressure within the supply system.
The injection pumps receive fuel from the manifold and force it under high pressure to the injection valves. The injection valves spray atomized fuel into the precombustion chambers.
An air vent valve in the system permits removal of air. Air is removed by opening the valve and pressurizing the fuel system. The system can be pressurized by using the priming pump. The vent valve must be open until a stream of fuel, without air bubbles, flows from the vent line.
Firing order (injection sequence), 3306 Engine … 1, 5, 3, 6, 2, 4
Firing order (injection sequence), 3304 Engine … 1, 3, 4, 2
A. Part number of fuel injection pump and governor group. B. Identification number on housing. C. Location of part number marks on camshaft.
NOTE: Early camshafts had no part number marks on the camshafts. All 4 cylinder camshafts without part number marks at location (C) are 4N4312.
NOTE: If the part number of the fuel injection pump and governor group is not in the chart or if it has a different camshaft, make reference to the parts book, or to TECHNICAL PARTSGRAM; COMMON USAGE IN SLEEVE METERING FUEL SYSTEMS, 4 and 6 PUMP GROUPS, Form No. FEG00707.
Torque for bolt in hole for timing pin … 108 ± 36 lb. in.(12.2 ± 4.1 N·m)
Torque for bolts that hold governor weight carrier to camshaft … 90 ± 10 lb. in.(10.2 ± 1.1 N·m)
(1) Diameter of rear bearing surface (journal) of the camshaft (new) … 2.3720 ± .0005 in.(60.249 ± 0.013 mm)
Bore in the rear bearing for the camshaft (new) … 2.3750 ± .0005 in.(60.325 ± 0.013 mm)
Maximum permissible clearance between the bore in the housing and the sleeve control shaft (worn) … .003 in.(0.08 mm)
(2) Diameter of sleeve control shaft (new) … .3530 ± .0003 in.(8.966 ± 0.008 mm)
Bore in the housing for the fuel control shaft (new) … .3543 ± .0005 in.(8.999 ± 0.013 mm)
Maximum permissible clearance between the bore in the housing and the sleeve control shaft (worn) … .003 in.(0.07 mm)
(3) End play for camshaft with sleeve installed (new) … .023 ± .018 in.(0.58 ± 0.46 mm)
NOTE: When installing sleeve on end of camshaft, support the camshaft to prevent damage to parts inside of injection pump and governor housing.
(4) Diameter of front bearing surface (journal) of the camshaft (new) … .9990 ± .0005 in.(25.375 ± 0.013 mm)
Bore in the front bearing for the camshaft (new) … 1.0005 ± .0005 in.(25.413 ± 0.013 mm)
Maximum permissible clearance between the bearing and the camshaft bearing surface (journal) (worn) … .003 in.(0.08 mm)
Install spring washer with bent side towards the governor spring (5) as shown.
(5) Governor spring:
Make reference to the chart “GOVERNOR SPRINGS.”
For the correct part number for the governor spring for the fuel injection pump and governor group, make reference to the following:
Parts book, RACK SETTING INFORMATION, TECHNICAL PARTSGRAM; COMMON USAGE IN SLEEVE METERING FUEL SYSTEMS, 4 and 6 PUMP GROUPS, Form No. FEG00707.
NOTE: If the engine has “surging”, install the 6N6901 Governor Conversion Group For Close Regulation (“Dashpot” Governor). Special Instruction, Form No. SMHS6762 has instructions for the installation procedures.
(6) Bypass valve:
NOTE: If the spring keeps the pressure in the fuel injection pump housing above 25 psi (170 kPa) with the engine operating under full load, the spring is good.
Pressure of fuel in housing for fuel injection pumps, (Full Load) … 30 ± 5 psi(205 ± 35 kPa)
Install guide pin (A) to depth (B) [.642 ± .003 in. (16.31 ± 0.08 mm)]. Slot in guide pin (A) must be in area shown from center of lifter.
(7) Torque for bushing … 70 ± 5 lb. ft.(95 ± 7 N·m)
(8) 4N4318 Spring for injection pump:
Length under test force … 1.35 in.(34.3 mm)
Test force … 12.5 ± 1.3 lb.(56 ± 6 N)
Free length after test … 1.566 in.(39.78 mm)
Outside diameter … .728 in.(18.49 mm)
(9) Torque for bolt holding sleeve on control shaft … 24 ± 2 lb. in.(2.8 ± 0.2 N·m)
(10) Torque for the nuts that hold the fuel lines (Use 5P144 Fuel line Socket) … 30 ± 5 lb. ft.(40 ± 7 N·m)
(11) Torque for the nuts that hold the nozzles … 105 ± 5 lb. ft.(142 ± 7 N·m)
(13) Put 5P3931 Anti-Seize Compound on threads of glow plug and tighten to … 120 ± 24 lb. in.(13.6 ± 2.8 N·m)
(14) Tighten nozzle finger tight on body.
(15) Torque for precombustion chamber (put 5P3931 Anti-Seize Compound on threads) … 150 ± 10 lb. ft.(205 ± 14 N·m)
NOTE: See Glow Plug Positioning.
(16) Torque for bolts holding clamps on fuel injection lines:
With rubber damper … 84 ± 24 lb. in.(9.6 ± 2.8 N·m)
Without damper … 108 ± 36 lb. in.(12.2 ± 4.1 N·m)
(17) Lever assembly.
(18) Clearance between lever assembly (17) and governor housing when shaft assembly (19) is pulled against the governor housing … .437 in.(11.10 mm)
(20) Spring for the terminal shaft. Install the spring (20) for the terminal shaft so that the end of the spring is in the 30° range as shown.
PLASTIC COVER ILLUSTRATED
(21) Torque for bolts holding plastic cover (without tapped hole) … 72 ± 9 lb. in.(8.2 ± 1.0 N·m)
NOTE: Use standard torque for bolts holding steel cover (with tapped hole).
HYDRAULIC STARTING SYSTEM DIAGRAM
1. Reservoir. 2. Hand pump. 3. Pressure gauge. 4. Hydraulic starting motor. 5. Starter control valve. 6. Hydraulic pump (driven by engine timing gears). 7. Unloading valve. 8. Filter. 9. Accumulator.
The hydraulic starting motor (4) is used to turn the engine flywheel fast enough to get the engine started. When the engine is running, the hydraulic pump (6) pushes oil through the filter (8) into the accumulator (9). The accumulator (9) is a thick wall cylinder. It has a piston which is free to move axially in the cylinder. A charge of nitrogen gas (N2) is sealed in one end of the cylinder by the piston. The other end of the cylinder is connected to the hydraulic pump (6) and the hydraulic starting motor (4). The oil from the hydraulic pump (6) pushes on the piston which puts more compression on the nitrogen gas (N2) in the cylinder. When the oil pressure gets to 3000 psi (20 700 kPa), the accumulator (9) has a full charge. At this point the piston is approximately in the middle of the cylinder.
The unloading valve (7) feels the pressure in the accumulator (9). When the pressure is 3000 psi (20 700 kPa) the unloading valve (7) sends the hydraulic pump (6) output back to the reservoir (1). At the same time it stops the flow of oil from the accumulator (9) back to hydraulic pump (6). At this time there is 3000 psi (20 700 kPa) pressure on the oil in the accumulator (9), in the line to the unloading valve (7), in the lines to the hand pump (2) and to the hydraulic starting motor (4).
Before starting the engine, the pressure on the pressure gauge (3) should be 3000 psi (20 700 kPa). When the starter control valve (5) is activated, the oil is pushed from the accumulator (9) by the nitrogen gas (N2). The oil flow is through the hydraulic starting motor (4), where the energy from the compression of the fluid is changed to mechanical energy for turning the engine flywheel.
Hydraulic Starting Motor
HYDRAULIC STARTING MOTOR
1. Rotor. 2. Piston. 3. Thrust bearing. 4. Starter pinion. A. Oil inlet. B. Oil outlet.
The hydraulic starting motor is an axial piston hydraulic motor. The lever for the starter control valve pushes the starter pinion (4) into engagement with the engine flywheel at the same time it opens the way for high pressure oil to get into the hydraulic starting motor.
When the high pressure oil goes into the hydraulic starting motor, it goes behind a series of pistons (2) in a rotor (1). The rotor (1) is a cylinder which is connected by splines to the drive shaft for the starter pinion (4). When the pistons (2) feel the force of the oil they move until they are against the thrust bearing (3). The thrust bearing (3) is at an angle to the axis of the rotor (1). This makes the pistons (2) slide around the thrust bearing (3). As they slide, they turn the rotor (1) which connects through the drive shaft and starter pinion (4) to the engine flywheel. The pressure of the oil makes the rotor (1) turn very fast. This turns the engine flywheel fast enough for quick starting.
The air starting motor is used to turn the engine flywheel fast enough to get the engine running.
AIR STARTING SYSTEM
1. Starter control valve. 2. Oiler. 3. Relay valve. 4. Air starting motor.
The air starting motor is on the right side of the engine. Normally the air for the starting motor is from a storage tank which is filled by an air compressor installed on the left front of the engine. The air storage tank holds 10.5 cu. ft. (297 liter) of air at 250 psi (1720 kPa) when filled.
For engines which do not have heavy loads when starting, the regulator setting is approximately 100 psi (690 kPa). This setting gives a good relationship between cranking speeds fast enough for easy starting and the length of time the air starting motor can turn the engine before the air supply is gone.
If the engine has a heavy load which can not be disconnected during starting, the setting of the air pressure regulating valve needs to be higher in order to get high enough speed for easy starting.
The air consumption is directly related to speed, the air pressure is related to the effort necessary to turn the engine flywheel. The setting of the air pressure regulator can be up to 150 psi (1030 kPa) if necessary to get the correct cranking speed for a heavily loaded engine. With the correct setting, the air starting motor can turn the heavily loaded engine as fast and as long as it can turn a lightly loaded engine.
Other air supplies can be used if they have the correct pressure and volume. For good life of the air starting motor, the supply should be free of dirt and water. The maximum pressure for use in the air starting motor is 150 psi (1030 kPa). Higher pressures can cause safety problems. The 1L5011 Regulating and Pressure Reducing Valve Group has the correct characteristics for use with the air starting motor. Most other types of regulators do not have the correct characteristics. Do not use a different style of valve in its place.
AIR STARTING MOTOR
5. Air inlet. 6. Rotor. 7. Vanes. 8. Pinion. 9. Gears. 10. Piston. 11. Pinion spring.
The air from the supply goes to relay valve (3). The starter control valve (1) is connected to the line before the relay valve (3). The flow of air is stopped by the relay valve (3) until the starter control valve (1) is activated. Then air from the starter control valve (1) goes to the piston (10) behind the pinion (8) for the starter. The air pressure on the piston (10) puts the spring (11) in compression and puts the pinion (8) in engagement with the flywheel gear. When the pinion is in engagement, air can go out through another line to the relay valve (3). The air activates the relay valve (3) which opens the supply line to the air starting motor.
The flow of air goes through the oiler (2) where it picks up lubrication oil for the air starting motor.
The air with lubrication oil goes into the air motor. The pressure of the air pushes against the vanes (7) in the rotor (6). This turns the rotor which is connected by gears (9) to the starter pinion (8) which turns the engine flywheel.
When the engine starts running the flywheel will start to turn faster than the starter pinion (8). The pinion (8) retracts under this condition. This prevents damage to the motor, pinion (8) or flywheel gear.
When the starter control valve (1) is released, the air pressure and flow to the piston (10) behind the starter pinion (8) is stopped, the pinion spring (11) retracts the pinion (8). The relay valve (3) stops the flow of air to the air starting motor.
The starter motor is used to turn the engine flywheel fast enough to get the engine running.
1. Field. 2. Solenoid. 3. Clutch. 4. Pinion. 5. Comutator. 6. Brush assembly. 7. Armature.
The starter 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 starter motor. When the start switch is released, the starter pinion will move away from the ring gear of the flywheel.
SCHEMATIC OF A SOLENOID
1. Coil. 2. Switch terminal. 3. Battery terminal. 4. Contacts. 5. Spring. 6. Core. 7. Component terminal.
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.
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.
A magnetic switch (relay) is used sometimes for the starter solenoid or glow plug circuit. Its operation electrically, is the same as the solenoid. Its function is to reduce the low current load on the start switch and control low current to the starter solenoid or high current to the glow plugs.
The alternator is driven by V-type belts from the crankshaft pulley. This alternator is a three phase, self-rectifying charging unit, and the regulator is part of the alternator.
This alternator design has no need for slip rings or brushes, and the only part that has movement is the rotor assembly. All conductors that carry current are stationary. The conductors are: the field winding, stator windings, six rectifying diodes, and the regulator circuit components.
The rotor assembly has many magnetic poles like fingers with air space between each opposite pole. The poles have residual magnetism (like permanent magnets) that produce a small amount of magnet-like lines of force (magnetic field) between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced in the stator windings from the small magnetic lines of force made by the residual magnetism of the poles. This AC current is changed to direct current (DC) when it passes through the diodes of the rectifier bridge. Most of this current goes to charge the battery and to supply the low amperage circuit, and the remainder is sent on to the field windings. The DC current flow through the field windings (wires around an iron core) now increases the strength of the magnetic lines of force. These stronger lines of force now increase the amount of AC current produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator.
The voltage regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output.
DELCO-REMY ALTERNATOR (Typical Example)
1. Regulator. 2. Roller bearing. 3. Stator winding. 4. Ball bearing. 5. Rectifier bridge. 6. Field winding. 7. Rotor assembly. 8. Fan.
The alternator is a three phase, self-rectifying charging unit that is driven by V-type belts. The only part of the alternator that has movement is the rotor assembly. Rotor assembly (4) is held in position by a ball bearing at each end of the rotor shaft.
The alternator is made up of a front frame at the drive end, rotor assembly (4), stator assembly (3), rectifier assembly, brushes and holder assembly (5), slip rings (1) and rear end frame. Fan (2) provides heat removal by the movement of air thru the alternator.
Rotor assembly (4) has field windings (wires around an iron core) that make magnetic lines of force when direct current (DC) flows thru them. As the rotor assembly turns, the magnetic lines of force are broken by stator assembly (3). This makes alternator current (AC) in the stator. The rectifier assembly has diodes that change the alternating current (AC) from the stator to direct current (DC). Most of the DC current goes to charge the battery and make a supply for the low amperage circuit. The remainder of the DC current is sent to the field windings thru the brushes.
1. Slip rings. 2. Fan. 3. Stator assembly. 4. Rotor assembly. 5. Brush and holder assembly.
Voltage Regulator (Motorola)
The voltage regulator is not fastened to the alternator, but is mounted separately and is connected to the alternator with wires. The regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output. There is a voltage adjustment for this regulator to change the alternator output.
ALTERNATOR REGULATOR (MOTOROLA)
1. Cap for adjustment screw.