View Single Post
Old 06-21-2013, 06:47 AM   #15
FF's Avatar
Join Date: Oct 2007
Posts: 18,265
How do you know 1650 is a safe RPM for the way he is propped?

Easy , he gets 1800 RPM and a glance at any prop graph shows loads drop very rapidly with lower RPM.

The usual safe HP is 10% less than the engine can pull ,
and HP required drops more than 10% on any prop graph with a 10% RPM reduction...

As there is no mention of blowing a fog of black smoke at his cruise of 1450 or even at 1800 , Id say the previous owner got it just right!

I wouldn't change a thing.Except to add a red line.
FF is offline   Reply With Quote