Related Words

Camshaft: A metal shaft with two or more cams (oval “lobes”) that rotates to operate inlet and/or exhaust valves in a four-stroke engine.

Overhead Camshaft (OHC): A camshaft in an internal-combustion engine that is mounted within the cylinder heads, above the combustion chambers, and drives the valves or lifters directly instead of using pushrods.

Rocker Arm: A centrally pivoted lever that transmits the motion of the camshaft to open and close the valves.

Rotary Engine: A powerplant that rotates on a stationary propeller shaft. An American invention by Adams-Farwell Co (1896), it was first used for buses and trucks in the US (1903), then copied by French en . . . View Full Definition

Pushrods: Pushrods are used to connect to rocker arm assemblies which, in turn, open and close valves. In this case, the Camshaft is located near the crankshaft. The rotation of the camshaft causes it . . . View Full Definition

Overhead Valve (OHV): A type of piston engine that places the camshaft in the cylinder block and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves. Lifters or tappets resi . . . View Full Definition

Bevel Drive Shaft: A shaft with a bevel gear at one end or both ends. It is used primarily for driving an overhead camshaft.

Double Overhead Cam (DOHC): Designation for engines that utilize one camshaft to open the engine intake valves and another to open the exhaust valves. This optimizes valve timing for better performance. (Compare SOHC).