Overhead Camshaft

An overhead camshaft, also called an overhead cam or abbreviated OHC, is a camshaft mounted above the cylinder heads rather than below the cylinders. The OHC activates the valves directly, eliminating the need for push rods. An overhead cam can consist of one (single overhead cam, or SOHC) or two (double overhead cam, or DOHC) camshafts. In a DOHC, on camshaft opens the intake valves, while the other opens the outlet valves.