CAMSHAFT: Describes a shaft with cam lobes (bumps) driven by gears, a belt, or a chain from the crankshaft.
CAM: Describes a metal disc with irregularly shaped lobes used in the camshaft to activate the valves' opening and closing and in the distributor to force the points to open.
CAMSHAFT HOUSING: DDescribes the part of the engine which encloses the camshaft and often other parts of the valve train.
CAMSHAFT PULLEY: DDescribes the pulley on the end of the camshaft that holds the camshaft drive belt.
OVERHEAD CAMSHAFT (OHC): Describes the camshaft whose role it is to activate the valves is mounted above the head and driven by a long timing chain, in contrast, to a pushrod engine where thin rods are moved by the camshaft and activate the valves. An overhead camshaft system allows for higher engine speed because of fewer moving valvetrain parts.
PHOSPHATE COATING: DDescribes a special conversion coating extracted through phosphating applied to camshafts to promote oil retention.
PUSH ROD: DDescribes the rod that connects the valve lifter to one end of the rocker arm. The rods, moved by the cam, activate the valve lifter. Engines with overhead cams do not need pushrods because the camshaft connects to the valves directly.
ROLLER TAPPETS: Describes a series of valve lifters with a roller placed on the end contacting the camshaft to reduce friction between the lobe and lifter.
SINGLE OVERHEAD CAM (SOHC): Describes a type of camshaft located between the valves and driven by a chain coming from the crankshaft with the valves opened by short rocker arms.