Without sufficient lubrication, the engine stops running within a few minutes. The thinnest oil film protects dynamic links and engine mechanisms from destructive friction, such as pistons and piston pins, cylinder working surfaces, connecting rods and main bearings of the crankshaft, parts of the gas distribution mechanism.
To ensure the constant presence of an oil film in the contacting parts, the oil circulates through pipelines and channels when the engine is running. The oil pump takes oil from the oil pan and distributes it through the channels of the lubrication system to the lubrication points. For cleaning, engine oil passes through an oil filter, which cleans it of wear products and other foreign matter. Cleaning is carried out until the microscopic pores of the oil filter are completely clogged with wear products.
When the filter is clogged, the safety valve starts to work, which, at a certain pressure, opens the auxiliary circulation channel. Unfiltered oil primarily causes rapid bearing wear. From the filter, the lubricant enters through the holes in the cylinder block to the bearings of the crankshaft, connecting rod and valve mechanism in the cylinder head. Due to the inclined position of the engine, it can drain from the lowest point of the cylinder head through the hole without additional heating into the oil bath. The cylinder walls and piston pins are lubricated by oil entering through the connecting rods.
Another important function of the oil is to remove heat from the surfaces being lubricated. The bottoms of the pistons are sprayed with oil from below, which is supplied not for lubrication, but for cooling.