Oil System Design Features
The engine lubrication system is combined: the most heavily loaded parts are lubricated under pressure, while the rest are lubricated by splash.
Pressure in the lubrication system is created by a gear oil pump installed in the engine oil sump at the front of the cylinder block and driven by a chain drive from the crankshaft.
The pump draws oil from the engine oil sump through an oil pickup with a mesh filter and then delivers it through a full-flow oil filter with a porous paper filter element to the main oil line located in the cylinder block body on the left side.
From the main line, oil supply channels extend to the crankshaft main bearings.
Oil is supplied to the connecting rod bearings through channels made in the crankshaft body.
From the main oil line, an oil supply channel extends to the camshaft.
In addition, oil is supplied under pressure from the engine main line to the timing chain tensioner and to the variable valve timing system of the intake valves.
To lubricate the camshaft bearings, oil from the vertical channel through a radial hole in The third bearing journal is fed through a hollow bolt into the rocker arm shaft axial bore, where it is distributed between the remaining camshaft bearings and the valve train rocker arms.
The camshaft lobes are lubricated by oil sprayed through the rocker arm holes.
Excess oil drains from the cylinder head into the oil sump through vertical drain channels.