This factory race motor features tappet blocks that are bolted to the crankcase rather than the earlier type which were part of the crankcase casting.
Instead of pivoted roller arms, the cam action is transmitted to the valves via roller tappets which ride directly on the cam, hence the name "direct-action" 2-cam.
Compare the tappet arrangement on this motor with the close-up photo of the 1924 "Indirect-action" 2-cam motor.
Installed: April 12, 1997|
Revised: June 28, 2003