I was told ground runs is one of the worst things you can do to an airplane
engine, as it was designed for sustained high RPM operations, not ground
run RPMS.

You know, I've heard that since Day One of ownership, too, but ya just
gotta wonder if it's not yet another "old wive's tale", like so many of
these "tried and true" things. How does the engine know the
difference between ground runs at, say 2000 RPM (run-up speed on our
plane) and an extended descent? Is *that* "bad" for the engine, too?

Doesn't running it for 30 minutes on the ground circulate the oil, and
prevent corrosion? Can't you get oil temps up to 150 or better (I
know, 180 is optimal, but...) with a ground run? Isn't that better
than letting it sit and rot till spring?

I fly too often for this to really matter, but I always wonder if it's
a real issue or not? Kinda like "shock cooling" and "pulling the prop
through" before starting on a cold day... And Marvel Mystery oil,
while we're at it...

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"