Camshaft, Lifters and Push Rods: Description and Operation

VALVE TRAIN
The valve train consists of:
Lifters/tappets
Hydraulic valve tappets (6500) which provide automatic lash adjustment.
Rocker Arms/Roller Followers
Rocker arms transfer the up and down motion of the camshaft lobes to the valves.
Valves
There are two valves per cylinder. The valves are arranged alternately intake valve (6507)/exhaust valve (6505).
Camshaft
There is one camshaft on each head. The camshaft (6250) is:
^ Seated in journal bores on top of the cylinder head.
^ Driven from the crankshaft by individual timing chains.
^ There is an automatic hydraulic timing chain tensioner (6L266) on each timing chain.