How Does Oil Flow in a Small Block Chevy?

A good lubrication system helps protect engine components from wear.

A good lubrication system is essential to the longevity of engine components. A full-pressure lubrication system sends oil to all the engine surfaces that have contact with each other.

Wet-Sump

A Chevy engine employs a wet-sump system. A supply of oil is stored underneath the crankshaft. Passages link this supply through the cylinder block and heads, and to the crankshaft itself.

Oil Pump

An oil pump sends the oil through a filter, onto a 1/2-inch gallery just above the camshaft. The oil is sent to the pump continuously through a 1/2-inch pump inlet.

Cam Bearings

The oil is sent through a groove near the rear cam bearing; it lubes the lifters and rear main bearings. The front cam bearings have grooves, which take the lube to the front main bearings.

Crankshaft

The oil passes through passages in the upper main bearings. It then moves through the crankshaft main journals to the rod journals.

Cylinders and Valve Stems

The crankshaft spins, and oil is thrown into the cylinders. Oil travels through the pushrods and over the rocker arms, lubing the valve stems.

References

• "Chevy High Performance"; Lubrication Systems; Bob Mehlhoff; February 2009