Professional engine builders are familiar with camshaft walk. Excessive camshaft end play can produce erratic spark timing and the movement of the timing chain/gear can destroy the timing cover. Moroso has solved this problem with a wear resistant cam stop button that mounts in an aluminum holder, which bolts to the cam gear by way of a retaining plate. These button assemblies do not allow the cam to walk forward, stabilizing ignition timing and preventing costly engine damage.
