Lubrication Description

Fig 1: Engine Oil Flow Diagram (Front View)

Courtesy of GENERAL MOTORS CORP.

Full pressure lubrication, through a full flow oil filter, is furnished by a gear type oil pump. The oil is drawn up through the pickup screen and the tube. The oil passes through the pump to the oil filter.

The oil filter is a full flow paper element unit. An oil filter bypass is used in order to ensure oil supply during the following conditions:

• On a cold start
• If the filter is plugged
• If the filter develops excessive pressure drop

The bypass is designed to open at 69-83 kPa (10-12 psi).

A new priority oil delivery system supplies oil first to the crankshaft journals. The oil from the crankshaft main bearings is supplied to the connecting rod bearings by intersecting the passages drilled in the crankshaft. The passages supply the oil to the crankshaft main bearings and the camshaft bearings through the intersecting vertical drilled holes. The oil passages from the camshaft journals supply oil to the hydraulic lifters.

The hydraulic lifters pump oil up through the pushrods to the rocker arms. The cast dams in the crankcase casting direct the oil that drains back from the rocker arms in order to supply the camshaft lobes. The camshaft chain drive is lubricated by indirect oil splash.

Fig 2: Engine Oil Flow Diagram (Rear View)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Engine Oil Flow Diagram (Right View)

Courtesy of GENERAL MOTORS CORP.