Design features of the engine lubrication system

The lubrication system is combined: the most loaded parts are lubricated under pressure, while the rest are lubricated either by directed spraying or spraying of oil flowing from the gaps between the mating parts. The lubrication system is pressurized by an internal trochoidal gear oil pump mounted externally at the front of the cylinder block and driven from the front end of the crankshaft.

The pump sucks oil from the engine oil sump through an oil receiver with a strainer and through a full-flow oil filter with a porous paper filter element delivers it to the main oil line located in the body of the cylinder block on the left side. Oil supply channels to the main bearings of the crankshaft depart from the main line. Oil is supplied to the connecting rod bearings through the channels made in the body of the crankshaft, and then through the channels in the rods of the connecting rods to the holes in their upper part, through which it is sprayed onto the cylinder walls and piston bottoms. A vertical channel for supplying oil to the camshaft housings and an upper longitudinal oil channel departs from the main oil line, connected by drillings in the block head with hydraulic gap compensators in the valve mechanism. A pressure reducing valve is screwed into the end part of the upper longitudinal channel, which limits the oil pressure in the cylinder head.

To lubricate the camshaft bearings, oil from the vertical channel enters the central axial channels of the camshafts through a radial hole in the neck of the third bearing and is distributed through them to the rest of the bearings.

The camshaft cams are lubricated with oil, which comes from the central axial channels through the radial holes in the cams. Excess oil is drained from the head of the block into the oil sump through vertical drainage channels.

Changing the engine oil and oil filter is described in Sec. «Changing engine oil and oil filter»), removal and installation of the oil pump are discussed in the next subsection.