Engine Lubrication: Description and Operation

The lubrication system is designed to provide optimum oil flow to critical components of the engine through its entire operating range. Oil is drawn into the oil pump through the oil pump screen cover and tube in the sump and is pumped through the oil bypass filter on the front side of the cylinder block. Oil enters the main oil gallery, where it is distributed to the crankshaft main journals and to both cylinder heads.

From the journals oil is routed through cross-drilled passages in the crankshaft to the crankpins, for connecting rod bearing lubrication.

Controlled leakage through cross-drilled passages in the crankshaft and connecting rod bearings is slung radially outward to cool and lubricate the cylinder walls as well as the entire connecting rod and piston, pin and ring assemblies.

The left cylinder head is fed from a drilling into the lateral supply passage feeding the main gallery at the front of the cylinder block.

The right cylinder head is fed from a drilling into the rear of the main gallery.

Main gallery pressure is reduced as it enters the cylinder head galleries through the use of fixed, serviceable orifices located at the upper part of the feed passages. This reduced pressure in the cylinder head galleries feeds the following:
^ Camshaft journals.
^ Hydraulic lash adjusters.
^ Timing chain tensioners.
^ Camshaft lobes and rocker arms, lubricated by splash created through valve train operation.