Blumlein's Plane Crash

[peter scott]

When you look at the length of the tappet adjustment screw and the amount of freedom that the cam follower arm would have in the event of a fully unscrewed adjustment it's difficult to understand how any excess stress is placed on the valve stem. I think the head of the adjuster can't pass through the threaded hole in the follower arm. One little note is interesting: "On later type valves the split taper collets fit under the shoulder at the top of each valve, and not around it as on early type valves." Does this suggest that the valve stem could slip through the collets on early type valves?

   

Peter