Did you shoot the mechanic after the second forced landing he caused?
(just being facetious, but I'll bet you and he parted ways after that)

Had a friend who "almost" had a cylinder blow apart on a Skymaster. It
was cracked about 3/4 the way around. Happened on a flight of young
eagles.
It was also the rear engine. He detected a bit of vibration and
returned to the airport.

David Johnson