"Bertie the Bunyip" wrote

Not to mention one extraordinary J-3 that just went on forever. I think
it did over 4,000 hours without even a top end and it lived in the
pattern.

Yep.

As many times Jay says over and over that pattern work will wear out an
engine, I just don't think that is a given.

The biggest thing I believe that backs it up, is that the average HP output
per hour is less than what it would be at an all day long 75% cruise power
setting.

That, plus the fact that the average single engine mill is built hell for
stout, and does not make much power per C.I.
--
Jim in NC