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| Illustration 1 | g01246669 |
Engine oil flow schematic (1) Oil passage to the rocker arm shaft (2) Oil passage to the idler gear in the flywheel housing (3) Oil passage to the gear bearings in the flywheel housing (4) Oil passage to the fuel injection pump housing and the governor (5) Rocker arm shaft (6) Lubrication passages in the valve lifter bore (7) Camshaft bearings (8) Piston cooling jets (9) Oil passage to timing gear housing (10) Oil passage to idler gear shaft (11) Oil manifold (12) Crankshaft main bearings (13) Oil supply line to the turbocharger (14) Oil supply line to the manifold in the cylinder block (15) Filter bypass valve (16) Cooler bypass valve (17) Turbocharger (18) Engine oil cooler (19) Oil return line from the turbocharger (20) Oil filters (21) Oil pan (22) Oil pump | |
Oil Flow Through the Oil Cooler, Oil Filters and the Engine
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| Illustration 2 | g01246670 |
Oil lines and filters (15) Filter bypass valve (16) Cooler bypass valve (20) Oil filters (23) Bypass valve body | |
When the engine is in operation and the temperature of the oil is normal, the oil pump (22) sends oil to the following areas:
- Bypass valve body (23)
- Engine oil cooler (18)
- Oil filters (20)
The oil moves from the oil filters (20) to the oil manifold (11). From oil manifold (11) in the right side of the cylinder block, oil is sent to the left oil manifold. The oil flows through drilled passages in the cylinder block. The oil from the oil manifold (11) is sent under pressure through drilled passages to the crankshaft main bearings (12). The oil flows through drilled holes in the crankshaft. This oil lubricates the connecting rod bearings. A small amount of oil is sent through the piston cooling jets (8). The piston cooling jets cool the pistons. Oil flows through grooves in the bores for the front and rear camshaft bearings. The oil flows into the lubrication passages in the valve lifter bore (6) .
Oil is flows through the oil passage in the rocker arm shaft (1) to the rocker arm shaft (5) on both cylinder heads. The oil flows through holes in the rocker arm shafts (5). This oil lubricates the valve system components within the cylinder head.
The fuel injection pump and the governor receive oil from a passage in the cylinder block. There is a small gear pump between the injection pump housing and the governor. This pump sends oil under pressure to the fuel injection pump and to the governor.
The idler gear bores receive oil from an oil passage to the idler gear shaft (10). Oil then goes through the shaft for the bearings of the idler gears. The idler gears are installed on the front and rear of the cylinder block.
The idler gear bearings get oil under pressure through an oil passage to the idler gear in the flywheel housing (2). The driven gear bearings get oil under pressure through an oil passage to gear bearings in the flywheel housing (4) .
Pressure oil is sent to the turbocharger bearings through an oil supply line to turbocharger (13). The oil goes out of the turbocharger (17) and flows back to the oil pan (21). The oil returns to the oil pan through the oil return line from the turbocharger (19) .
There is a bypass valve in the oil pump. This bypass valve controls the maximum pressure of the oil from the oil pump. The oil pump can supply more than enough oil. The system will not use all the oil that is supplied by the oil pump. The excessive oil in the system will increase oil pressure. This will cause the bypass valve to open. This allows the oil that is not needed to go back to the inlet oil passage of the oil pump.
After the oil has lubricated all components, the oil returns to the engine oil pan.
When the engine is cold (starting condition), the filter bypass valve (15) and the cooler bypass valve (16) open. Cold oil has a high viscosity. This causes a restriction to the oil flow through the engine oil cooler (18) and the oil filters (20). When the bypass valves open, the oil flows directly from the oil pump to the oil manifold (11). This will give immediate lubrication to all components until the engine becomes warm.
When the oil gets warm, the pressure difference in the filter bypass valve (15) and the cooler bypass valve (16) decreases and the bypass valves close. There is a normal flow through oil cooler (18) and oil filters (20) .
The bypass valves will also open when there is a restriction in the oil cooler or the oil filter. This will allow lubrication of the engine when restrictions are present.