Craig:

The side loads at the very low rpms with cold oil are a factor in my mind. If it drops 50 rpm, the prop governor is working! Now, in a twin, I do cycle all the way down to be certain that the thing will feather. Not the same concern as in a single.

Walter


On Apr 5, 2005, at 6:36 PM, Craig Berland wrote:

Gene: **my engine builder ademently expressed that I
not pull rpm down to much when cycleing prop, no more than 50rpm or I
could scuff a piston on my low time tight cold engine.**

***That's actually very good advice on all engines of all times in service.Walter***
 
Walter, the logic escapes me???  I could see the concern if you were at WOT and
pulled the prop back 800 RPM or so.  But, 50 RPM at part throttle during run up??
I would be more concerned that the prop governor did not work that the engine
being hurt by 150 RPM drop at part throttle.
Craig Berland