On Tue, 27 Apr 2004 wrote:

I mean the engine's going to have this 74" diameter prop on it and
it's bound to vibrate some. How do you tell what's normal and what
isn't?


Burt Rutan says that the prop should turn about 2600 rpm static, and that
also makes a very good cruise rpm. My setup would turn my first prop
over 3000 static, but my good prop only 2400. I use that same number
for my cruise rpm which is 5200 rpm engine speed. I know that it will
run for hours at that speed. No doubt, others will be more sophisticated.

If you do find a resonant rpm, you'll know it right away.

George Graham
RX-7 Powered Graham-EZ, N4449E
Homepage http://bfn.org/~ca266