Dale wrote
He could not overboost since it was not turboed.
Hmm. Try leaving the throttle in and pulling the prop back.

Never heard that called overboost, but OK. Never saw him do that
either.

Do I KNOW that this caused the problem? Not really. But I know two
pilots who lost a jug on takeoff. He was one; the other flew a
jumpship owned by a non-pilot non-mechanic.

You know 3 now. I lost a jug on a PW 1830 (a few minutes after takeoff
actually) and I can assure you that engine was never shock-cooled.

And the jug actually came off? When I say lost a jug, I do mean a
cylinder cracked and came off the engine.

I know LOTS of people who had stuck/munched valves.

Michael