Ground running does not scavenge the vapors since the vent
system depends on airspeed.



--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Jay Honeck" wrote in message
oups.com...
| 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"
|