General Information

NOTE: For Specifications with illustrations, make reference to Specifications For 3054 Truck Engine, SENR1117. If the Specifications in SENR1117 are not the same as in the Systems Operation and the Testing & Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

Engine Design

Type ... Four Cylinder, Four Stroke

Combustion System ... Direct Injection

Nominal Bore ... 100 mm (3.937 in)

Stroke ... 127 mm (5.00 in)

Cubic Capacity ... 4 liters (243 cu in)

Compression Ratio ... 16 to 1

Number and Arrangement of Cylinders ... in-line, 4

Firing Order ... 1-3-4-2

Rotation of crankshaft (as seen from front of engine) ... Clockwise

Rotation of camshaft (as seen from front of engine) ... Clockwise

The left side and right side of engine are as seen from flywheel end. No. 1 cylinder is the front cylinder of the engine.

Engine Serial Numbers

Engine Serial Number Location

The engine serial number is located on the left side of the cylinder block.

Fuel System

Basic Fuel System Diagram (Typical Example)
(1) Fuel injection nozzle. (2) Fuel return line. (3) Cold start heater (thermostart). (4) Fuel return line. (5) Fuel return line. (6) Fuel supply line. (7) Fuel filter. (8) Fuel lift pump. (9) Water separator. (10) Fuel injection pump. (11) High pressure fuel lines. (12) Fuel tank.

When the engine is turning, fuel is pulled from fuel tank (12) through water separator (9) by fuel lift pump (8). When the fuel goes through the water separator, any water in the fuel will go to bottom of the bowl. The fuel lift pump sends the fuel at a low pressure to fuel filter (7). From the fuel filter, the fuel goes through fuel supply line (6) to fuel injection pump (10). The fuel injection pump sends fuel through high pressure fuel lines (11) to each fuel injection nozzle (1), and the fuel injection nozzle sprays fuel into the cylinder. Fuel not used by the fuel injection pump goes through fuel return line (5) to the inlet side of fuel filter (7).

Leakage from the fuel injection nozzles flows through fuel return line (2) to the top of fuel filter (7) and back to fuel tank (12), through fuel return line (4).

The fuel injection pump needs fuel for lubrication. The precision parts of the pump are easily damaged. For this reason, the engine must NOT be started until the injection pump is full of fuel that is free of air.

The system must be primed any time any part of the system is drained of fuel. When the fuel filter is changed or a fuel line is removed, when the inspection cover on the fuel injection pump is removed for service or repair, the fuel system must be primed (air removed). See, Remove Air From Fuel System in Testing & Adjusting.

There is a small screen in fuel lift pump (8). The pump also has a manual lever to prime the fuel system (remove the air). The orifice in the cover of fuel filter (7), to release air in the system, is in the inlet side of the filter. The orifice is connected to the fuel tank by fuel return line (4).

Cold start heater (3) is installed in the inlet manifold. It is controlled by a remote mounted control switch.

Fuel Injection Nozzle

Fuel Injection Nozzle
(1) Fuel return. (2) Cap nut. (3) Fuel inlet. (4) Pressure adjusting screw. (5) Pressure adjusting spring. (6) Body. (7) Spring spindle. (8) Nozzle retaining nut. (9) Needle valve. (10) Nozzle. (11) Orifices (four). (12) Sealing washer.

Fuel, under high pressure from the fuel injection pump, goes through the hole in fuel inlet (3). The fuel then goes around needle valve (9), fills the inside of nozzle (10) with fuel and pushes against needle valve (9) and pressure adjusting spring (5). When the force made by the pressure of the fuel is more than the force of pressure adjusting spring (5), needle valve (9) will lift. When needle valve (9) lifts, fuel under high pressure will go through orifices (11) into the cylinder. When the fuel is sent to the cylinder, the force made by the pressure of the fuel in the nozzle body will become less. The force of pressure adjusting spring (5) will then be more than the force of the pressure of the fuel in the nozzle body. Needle valve (9) will move quickly to the closed position.

Needle valve (9) has a close fit with the inside of the nozzle. This makes a positive seal for the valve.

When the fuel is sent to the cylinder, a small quantity of fuel will leak by the valve guide. This fuel gives lubrication to the moving parts of the fuel injection nozzle. This fuel then goes through a leak off passage in body (6) to fuel return (1) to the fuel tank.

Fuel Injection Nozzle
(2) Cap nut. (6) Body. (8) Nozzle cap nut. (10) Nozzle.

Fuel Injection Pump

Fuel Injection Pump Components
(1) Control lever. (2) Flyweights. (3) Full-load adjusting screw. (4) Drive shaft. (5) Governor lever. (6) Solenoid. (7) Distributor head. (8) Control sleeve. (9) Feed pump. (10) Roller holder. (11) Plunger. (12) Cam disk. (13) Timer. (14) Plunger spring. (15) Delivery valve.

The fuel injection pump is a totally enclosed and pressurized system. The pump sends the correct amount of high pressure fuel through fuel injection nozzles, to individual cylinders at the correct time (near end of compression stroke). The fuel injection pump meters (measures) amount of fuel delivered to the fuel injection nozzles. This action controls engine speed by the governor setting or position of the accelerator or throttle control.

The fuel lines to the fuel injection nozzles are equal lengths. This insures even pressure and correct injection timing at each fuel injection nozzle.

During operation, extra fuel which is used as coolant and lubricant for pump parts that move is circulated through the pump housing and returned to the tank. Return lines also carry away any air trapped in the fuel injection nozzles or pump housing.

Cross Section View Of Pump
(4) Drive shaft. (6) Solenoid. (8) Control sleeve. (11) Plunger. (12) Cam disk. (14) Plunger spring. (15) Delivery valve. (16) Gear.

The fuel injection pump combines fuel transfer and high pressure pump functions in a single unit. A cam disk (12), driven from the engine by a gear (16) is pinned to plunger (11), which has a double motion. Lobes on the cam disk (12) cause the plunger to reciprocate, alternately drawing fuel and pressurizing it. Plunger (11) also rotates with the cam disc (12) to align its discharge groove successively with each of the four injector ports on the pump body.

The distance plunger (11) moves is fixed by the cam lobes; the effective stroke is determined by the position of the control sleeve. Moving the control sleeve to the left uncovers the spill port, before the beginning of injection, reducing the amount of fuel delivered. Moving the control sleeve to the right blocks the spill port, so that more fuel is delivered.

The pump also includes a timer (13), which initiates injection early by advancing the plunger carrier assembly relative to the cam plate during high speed operation.

Solenoid (6) is normally closed. When voltage is applied, the plunger moves down to block fuel delivery and stop the engine.

Fuel Flow

The operating principles of the pump can be understood better by following the fuel circuit during a complete pump cycle.

Fuel is drawn from the fuel tank through filters into the pump inlet through the inlet filter screen by the vane type fuel transfer pump. Some fuel is bypassed through the pressure regulator assembly to the suction side.

Fuel under transfer pump pressure flows through the center of the transfer pump rotor, past the rotor retainers into a circular groove on the rotor. It then flows through a connecting passage in the head to the automatic advance and up through a radial passage and then through a connecting passage to the metering valve. The radial position of the metering valve, controlled by the governor, regulates flow of the fuel into the radial charging passage which incorporates the head charging ports.

As the rotor revolves, the two rotor inlet passages register with the charging ports in the hydraulic head, allowing fuel to flow into the pumping chamber. With further rotation, the inlet passages move out of registry and the discharge port of the rotor registers with one of the head outlets. While the discharge port is opened, the rollers contact the cam lobes forcing the plungers together. Fuel trapped between the plungers is then pressurized and delivered by the fuel injection nozzle to the combustion chamber.

The fuel injection pump is self-lubricating. As fuel at transfer pump pressure reaches the charging ports, slots on the rotor shank allow fuel and any entrapped air to flow into the pump housing cavity.

An air vent passage in the hydraulic head connects the outlet side of the transfer pump with the pump housing. This allows air and some fuel to be bled back to the fuel tank through the return line. The bypassed fuel fills the housing, lubricates the internal components, cools and carries off any small air bubbles. The pump operates with the housing completely full of fuel. There are no dead air spaces within the pump.

Cold Start Heater

Cold Start Heater
(1) Fuel line to heater. (2) Cold start heater. (3) Cold start heater wire.

The engine is equipped with a cold start heater. Cold start heater (2) is installed in the inlet manifold to heat the inlet air in cold weather.

When the ignition switch is turned to the heat position or the control switch is pushed in and the fuel shutoff control is ON, current from cold start heater wire (3) will cause coil in cold start heater (2) to become very hot. A small amount of fuel will flow through fuel line to heater (1) when the engine is cranking.

Cold Start Heater
(5) Fuel inlet. (6) Ball valve. (7) Valve body. (8) Coil.

Valve body (7) is heated and expands which opens ball valve (6) and permits the fuel to go into valve body (7) from fuel inlet (5).

The fuel is turned into a vapor by the heat of the valve body and as the engine is turned, air is brought into the inlet manifold. The vapor is ignited by coil (8) and continues to burn which heats the inlet air.

When the ignition switch is turned to RUN position or the control switch is released, the flow of air in the inlet manifold makes the valve body cool quickly. The valve closes and turns off the fuel supply from fuel line to heater (1).

If the engine does not start after 20 seconds, turn the ignition switch to the HEAT position or push the control switch in again for 10 seconds and then crank the engine again.

Cooling System

Coolant from the bottom of the radiator passes through the centrifugal water pump which is installed on the front of the timing case. The pump is gear driven from the gear of the fuel injection pump and assists the flow of the coolant through the system. From the pump, the coolant passes through a passage in the timing case to the front of the cylinder block.

The coolant passes through a passage in the left side of the cylinder block to the rear of the cylinder block. Where a lubricating oil cooler is installed, some of the coolant passes around the element of the cooler and then to the rear of the cylinder block. The oil cooler is installed on the left side of the engine, coolant from the by-pass connection at the rear of the water pump passes through a pipe to the oil cooler. The coolant passes around the plates of the cooler and passes through a pipe to the cylinder block. The coolant then passes around the cylinders and up into the cylinder head. The coolant leaves the cylinder head at the front and passes into the thermostat housing. If the thermostat is closed, the coolant goes directly through a by-pass to the inlet side of the water pump. If the thermostat is open, the thermostat closes the by-pass and the coolant passes to the top of the radiator.

Lubrication System

Lubrication System
(1) Suction. (2) High pressure. (3) Reduced pressure. (4) Splash, Drain.

Lubrication System

Lubricating oil is supplied by a rotor type pump which is driven through an idler gear from the crankshaft gear. The pump has an inner rotor and an outer rotor which are off-center to each other. There is a key between the inner rotor and the drive shaft. The inner rotor has six lobes which mesh with the seven lobes of the outer rotor. When the pump turns, the space between the lobes of the outer rotor which are in mesh increases to cause a suction or decreases to cause a pressure increase.

Lubricating oil from the sump passes through a strainer and pipe to the suction side of the pump.

The lubricating oil passes from the outlet side of the pump through a pipe to a relief valve, which is installed to the bottom of the left side of the cylinder block. The relief valve opens if the oil pressure is too high; this allows some of the lubricating oil to return to the sump.

From the relief valve, lubricating oil passes to a plate type oil cooler (some naturally aspirated engines do not have an oil cooler). The oil cooler is either installed to the left side of the cylinder block and has seven plates, or it is installed between the oil filter head and the filter canister and has ten plates. Some oil coolers are equipped with a by-pass valve. If cold oil increases the restriction in the cooler, the by-pass valve opens and the oil passes directly from the inlet side to the outlet side of the cooler.

Lubricating oil from the oil cooler passes to an oil filter. The oil filter can be installed to the left or right side of the engine. If the filter is installed to the right side of the engine, the oil passes through a pipe connected between the relief valve and the right side of the cylinder block. The oil passes from the pipe through a passage in the right side of the cylinder block to an oil cooler and then to the oil filter. When the oil filter is on the right side of the engine, and an oil cooler is installed, the oil cooler will be between the oil filter head and the oil filter canister.

The lubricating oil passes from the filter to the pressure gallery which is drilled the complete length of the left side of the cylinder block. If the oil filter is on the right side of the engine, the oil passes through a passage drilled across the cylinder block to the pressure gallery.

From the pressure gallery, lubricating oil passes to the main bearings of the crankshaft and through passages in the crankshaft to the large end bearings of the connecting rod. The pistons and the cylinder bores are lubricated by splash and oil mist.

Lubricating oil passes from the main bearings through passages in the cylinder block to the journals of the camshaft. Lubricating oil passes, at a reduced pressure, from the center journal of the camshaft through a passage in the cylinder block and cylinder head to the rocker arm shaft. The oil passes through a passage in the rocker arm shaft to the bearings of the rocker arm levers. The valve stems, valve springs and the tappets are lubricated by splash and oil mist.

The hub of the idler gear is lubricated by oil from the pressure gallery and the timing gears are splash lubricated.

The turbocharger is lubricated by oil from the oil filter. Oil is supplied from a connection on the right side of the cylinder block through an external pipe to the turbocharger. The oil passes through the turbocharger and returns through a pipe to the sump.

Turbocharged engines have piston cooling jets installed. These jets are connected to the oil pressure gallery and spray lubricating oil inside the pistons to keep them cool.

Air Inlet And Exhaust System

Air Inlet Components (typical example)
(1) Inlet manifold. (2) Air inlet hose. (3) Exhaust manifold.

The air inlet and exhaust system components are: inlet manifold (1), air inlet hose (2), the cylinder head valves and valve mechanism components, exhaust manifold (3).

The turbocharger, is installed between the exhaust and inlet manifolds. The turbocharger is driven by exhaust gases and supplies air to the engine at pressures higher than atmospheric pressure. Air is pulled in the air inlet system by the inlet stroke of the piston. The air flows in the air cleaner, through air inlet hose (2) that directs the volume of air to inlet manifold (1). The air flows through inlet manifold (1) which directs even distribution of the air to each cylinder where the air is mixed with fuel from the injectors. The sequence and action of the engines' four cylinders and four strokes, (compression, power, exhaust and inlet) give constant air flow to the inlet system for engine operation.

Lubricating oil is supplied from the engine. Oil flows through the cartridge housing and is returned to the crankcase via a drain tube.

Turbochargers with waste-gates are controlled by boost pressure. This allows some of the exhaust gases to bypass the turbine rotor at higher engine speeds. With this arrangement, the turbocharger can be designed to be more effective at lower engine speeds.

The action of the exhaust stroke and the timing of the valve mechanism pushes combustion fumes out of the open exhaust valve through the exhaust manifold.

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

3054 Cylinder And Valve Location

The inlet and exhaust valves are opened and closed by the rotation and movement of the crankshaft, camshaft, tappets (valve lifters), push rods, rocker arms and valve springs. Rotation of the camshaft gear is driven by, and timed to the crankshaft gear. When the camshaft turns, the tappets are moved up and down. This movement makes the push rods move the rocker arms, which in turn makes the inlet and exhaust valves open and close according to the firing order of the engine. The valve springs push the valves back to the closed position.

There is one inlet and one exhaust valve for each cylinder. An exhaust valve seat can be installed in the cylinder head for service. The valve seat for the inlet valve is machined into the cylinder head and cannot be removed.

The air inlet system is also equipped with a crankcase ventilation system, or breather. The piston inlet stroke pulls in atmospheric air to the crankcase area.

Electrical System

The electrical system is a 12 volt, negative ground system. The electrical system can have 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, 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 charging circuit is in operation when the engine is running. The alternator in the charging circuit gives direct current (DC) to the electrical system.

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

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.

Starter Motor

The starting motor is used to turn the engine flywheel fast enough to make the engine run. The starting motor has a solenoid. When the ignition switch is activated, voltage from the electrical system will cause the solenoid to move the pinion toward the flywheel ring gear of the engine. The electrical contacts in the solenoid close the circuit between the battery and the starting motor just before the pinion engages the ring gear. This causes the starting motor to rotate. This type of motor "turn on" is a positive shift starting motor.

When the engine begins to run, the overrunning clutch portion of the pinion drive prevents damage to the armature caused by excessive speeds. The clutch does this by breaking the mechanical connection. The pinion will stay meshed with the ring gear however, until the ignition switch is released. A return spring in the overrunning clutch returns the clutch to its rest position.

Alternator

The alternator is an electrical and mechanical component driven by a belt from engine rotation. It is used to charge the storage battery during the engine operation. The alternator is cooled by an external fan mounted behind the pulley. The fan pulls air through the holes in the back of the alternator. The air exits the front of the alternator, cooling it in the process.

The alternator converts mechanical and magnetic energy to alternating current (AC) and voltage. This process is done by rotating a direct current (DC) electromagnetic field (rotor) inside a three phase stator. The alternating current and voltage (generated by the stator) are changed to direct current by a three phase, full wave rectifier system. Direct current flows to the alternator output terminal. The rectifier also has three exciter diodes. They rectify the current needed to start the charging process.

The alternator is connected to the battery through the ignition switch for alternator turn-on. Therefore, alternator excitation occurs when the switch is turned on.