What now appears to be the problem in my 216 head may be of interest to some, especially Jerry.
The intake valves in the 216 "wear" metal "hats" to keep too much oil from being sucked down into the valve guides. These "hats" are intended to be in direct contact with the top of the valves so that when the rocker pushes down the force is transferred through the "hat" to the valve below. Kinda like being tapped on the head when you are wearing a baseball cap that has some space above it - first the cap compresses and then you would feel the tap on your head.
Using the wrong keepers not only keeps a lessenned tension on the spring, it also causes a gap inbetween the "hat" and the top of the valve. The hat is now pushing first on the valve spring caps and then on the top of the valve. This constant jarring of the valve spring caps caused the taperred keepers to come loose and hence the sucked valve.
Thought that this might be of interest as a note of caution for those who are machining their heads.
Thanks again to all.
Michael
