WHAT IS AN OVERHEAD CAM?
An overhead cam, or overhead camshaft, is the part of a vehicle’s engine responsible for opening and closing the valves which allow the air/fuel mixture to enter the engine’s combustion chamber and exhaust to exit. The overhead camshaft is located in the cylinder head of the engine instead of in the cylinder block, as with an in-block camshaft. An overhead cam is popular due to the increase in the car engine’s performance compared to other camshaft arrangements, such as cam-in-block. The two major types include single overhead camshaft and double overhead camshaft. When double camshafts are present, one controls the intake valves while the other controls the exhaust valves.
