The camshaft is gear driven from the crankshaft. A replaceable bushing is used for the front journal to carry the
side loading from the accessory drive. The remainder of the journals operate in cast iron bores in the cylinder
block; however, these bores can be repaired in a machine shop by installing service bushings.
The camshaft has lobes to operate the intake and exhaust valves and a special lobe to drive the fuel transfer pump.
The valve lobes contact “ mushroom” shaped valve tap pets which operate the push rods. The operating arm of
the fuel transfer pump rides directly on the special lobe on the camshaft. The profile of the camshaft lobes is the
same for all B Series engines except 1994 automotive engines which use a new early intake valve opening in take lobe.
The tappets are mushroom shaped. The convex shape of the surface which contacts the camshaft lobe causes the
tappet to rotate as it lifts the push rod.
The ball end of the push rod fits into a ball socket in the tappet. The other end of the push rod is fitted with a socket
into which the ball end of the rocker lever adjusting screw operates.
