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| Illustration 1 | g00927483 |
Main oil pump and lubrication system schematic (1) Main oil gallery (2) Left camshaft oil gallery (3) Piston cooling jet oil gallery (4) Piston cooling jet oil gallery (5) Right camshaft oil gallery (6) Oil supply lines (7) Sequence valve (8) Sequence valve (9) Adapter (10) Engine oil filter bypass valve (11) Engine oil cooler (12) Engine oil cooler bypass valve (13) Oil pump relief valve (14) Engine oil pump (15) Suction bell (16) Duplex oil filter assembly | |
The engine lubrication oil system is pressurized by a positive displacement pump (14) with three pump gears that is driven by the engine. The pump pulls engine oil through a suction bell and screen assembly that is located in the engine oil sump. The oil screen is accessed through the forward end of the engine oil sump in the sub-base. Engine oil is pulled from the pan through suction bell (15) by engine oil pump (14). Suction bell (15) has a screen in order to clean the engine oil.
The engine oil pump delivers the engine lubrication oil to the engine oil cooler (11). The engine lubrication oil is then delivered to a duplex oil filter assembly (16). Bypass valves (12) are located at the engine oil cooler and the duplex oil filter assembly. This will ensure that full flow of the engine lubrication oil is maintained if the engine oil cooler becomes obstructed or the duplex oil filter becomes obstructed. The bypass valves for the engine oil cooler and the duplex oil filter will open if the engine oil viscosity is high at engine start-up due to low engine temperature.
The engine oil pump incorporates an integral relief valve (13) that maintains system pressure by relieving excess pump discharge pressure to the pump suction port. There is an oil pump relief valve (13) in the engine oil pump. The oil pump relief valve controls the pressure of the engine oil from the engine oil pump. This allows the engine oil that is not needed to go back to the inlet oil passage of the engine oil pump.
The engine oil pump pushes oil through engine oil cooler (11). The engine oil flows to main oil gallery (1) and left camshaft oil gallery (2) in the cylinder block. Engine oil cooler (11) lowers the temperature of the engine oil before the engine oil is sent to the filters.
Engine oil cooler bypass valve (12) allows engine oil to flow directly to the filters if engine oil cooler (11) becomes plugged or if the engine oil becomes thick enough to increase the oil pressure differential by 180 ± 20 kPa (26 ± 3 psi).
Engine oil filters are located in duplex oil filter assembly (16) at the front of the engine. A single bypass valve is located in the engine oil filter housing.
Clean engine oil from the filters goes through adapter (9) into the cylinder block. Part of the engine oil goes to left camshaft oil gallery (2). The remainder of the engine oil goes to main oil gallery (1) .
Left camshaft oil gallery (2) and right camshaft oil gallery (5) are connected to each camshaft bearing by a drilled hole. The engine oil goes around each camshaft journal. The engine oil then travels through the cylinder head and the rocker arm housing to the rocker arm shaft. A drilled hole connects the bores for the valve lifters to the oil hole for the rocker arm shaft. The valve lifters are lubricated at the top of each stroke.
The main oil gallery is connected to the main bearings by drilled holes. Drilled holes in the crankshaft connect the main bearing oil supply to the rod bearings. Engine oil from the rear of the main oil gallery goes to the rear of the right camshaft oil gallery.
Sequence valve (7) and sequence valve (8) allow engine oil from the main oil gallery to go to both piston cooling jet galleries (3) and (4). The sequence valves begin to open at approximately 130 kPa (19 psi). The sequence valves will not allow engine oil into the piston cooling jet galleries until there is pressure in the main oil gallery. This decreases the amount of time that is necessary for pressure buildup when the engine is started. This also helps to maintain the proper engine oil pressure at low idle speed.
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| Illustration 2 | g00927541 |
Piston cooling and lubrication (17) Piston cooling jet | |
There is a piston cooling jet (17) below each piston. Each cooling jet has two openings. One opening is in the direction of a passage in the bottom of the piston. This passage takes engine oil to a manifold behind the ring band of the piston. A slot (groove) is in the side of both piston pin bores. This slot connects with the manifold behind the ring band. The other opening is in the direction of the center of the piston. This helps cool the piston and this supplies lubrication to the piston pin.
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| Illustration 3 | g00927543 |
Turbochargers (6) Oil supply lines (18) Oil drain lines | |
Oil supply lines (6) send oil from the rear adapter to the turbochargers. Oil drain lines (18) are connected to the flywheel housing on each side of the engine.
Engine oil is sent to the front and rear gear groups through drilled passages. The drilled passages are in the front housing, the rear housing, and the faces of the cylinder block. These passages are connected to left camshaft oil gallery (2) and right camshaft oil gallery (5) .
After the engine oil flows through the lubrication system, the engine oil returns back to the engine oil pan.
Engine Prelubrication System
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| Illustration 4 | g00927477 |
(19) Discharge for prelubrication oil (20) Prelubrication oil pump (21) Pickup for prelubrication oil | |
The engine is also equipped with a manual prelubrication oil pump, which may be used to lubricate the engine before starting. The engine does not normally require the prelubrication of the engine oil system prior to starting unless the engine has not been ran for a prolonged period of time. For example if the engine has not been run for thirty days, then the engine needs to be prelubed. Cranking the handle of the manual prelubrication oil pump will prelube the engine. The prelubrication oil pump will deliver one gallon of oil to the engine for every eight and one half turns of the handle. After extended periods of shutdown, cranking the handle for a period of one minute will provide sufficient lubrication for starting. The manual prelubrication oil pump pulls from the integral sump on the right side of the sub-base. The manual prelubrication oil pump provides oil to the engine at a connection near the oil cooler. The engine prelubrication system is provided with check valves in order to prevent pressurization of the engine prelubrication system with normal engine oil pressure when the engine is operating.