PART 2 of 2
Engine lubrication is absolutely essential for an internal combustion engine to run, and it’s the oil that makes the whole system possible. The lubrication system performs the following functions in an engine: The oil lubricates moving parts to minimize wear by sealing the clearances between moving parts such as bearings, shafts, etc. Thus, the parts move on layers of oil, and not in direct contact with each other, which reduces power loss in the engine. The oil obtains heat from the moving parts of the engine which is transferred into the cooler oil in the oil pan. Therefore, the oil performs the function of a cooling agent. Some engines have oil nozzles which spray oil at the underside of the pistons, thereby removing heat from the pistons. The oil fills the clearances between rotating journals and the bearings. When heavy loads are abruptly placed on the bearings, the oil acts as a cushioning agent, which reduces the wear on bearings. The oil creates a seal between the walls of the cylinder and the piston rings, thereby reducing exhaust gas blowby. The oil performs the function of a cleaning agent by picking up dirt particles and taking them to oil pan. Larger particles are retained at the bottom while smaller particles are filtered out by oil filters.