Engine Lubrication: Description and Operation

General description
The engine lubrication system consists of an oil pan, oil pump, oil filter and various oil passages. A rotor-type oil pump is driven by crankshaft. The oil pump has a pressure relief valve which controls lubrication system pressure by bypassing oil back to oil pan. The oil pump rotates and draws oil from the oil pan through an oil strainer. The oil is pressurized as it passes through the pump.
Pressurized oil is first directed through a full-flow paper element where impurities are removed, and then to a main oil gallery. Oil in this gallery is divided into two passages. In one passage, oil is pumped to the crankshaft main bearings. Oil is supplied to the connecting rod bearings through intersecting passages drilled in the crankshaft. Piston cooling jets in each cylinder provide additional piston cooling and lubrication. In the second passage, oil flows to the cylinder head to lubricate valve train components.
After passing through the cylinder block and cylinder head, oil is returned by gravity to the oil pan. Those internal parts that have no direct oil feed are supplied with lubrication by either gravity or splash from other direct feed components.