How Does Oil Flow in a Small Block Chevy?

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.