General description of the engine lubrication system

The engines of the described vehicles have a forced circulation lubrication system with a gear oil pump, a strainer oil filter and an oil cooler. The oil pump is directly connected to and driven from the camshaft. The pump sucks oil through a screen from the oil sump and pumps it through the oil cooler into the oil channels.

A relief valve located upstream of the oil cooler controls the flow of engine oil through the oil cooler depending on the oil temperature. With cold, viscous oil, the valve piston is closed. The oil flows directly to the lubrication points, part of it returns to the crankcase. When the oil temperature rises, its pressure drops, the safety valve piston gradually blocks the direct path to the lubrication points. The oil passes partly through the radiator and partly directly to the lubrication points. When the engine is hot, the valve piston moves to its highest position. In this case, the oil enters the lubrication points only through the oil cooler.

A bypass valve is installed at the end of the crankshaft to stabilize oil pressure. It opens at a pressure of 2.8 bar (atm).