These numbers don't sanity check Buly. I turned my engine 6400 with
68" prop and 2.17 drive when racing and never had the characteristic
snapping prop noise that accompanies supersonic tip speeds.
Monty's "one empirical test is worth more than 1000 calcs ....." seems
appropriate here : )
Tracy
----- Original Message -----
Sent: Monday, December 19, 2005 1:13
PM
Subject: [FlyRotary] Props
Yesterday somebody gave me the formulas to calculate the prop
tip
speed. I did some calculations and looks like us with the
2.17
redrives are kind of painted in the corner. Hope I'm wrong, but
if I
want to keep the tips from going supersonic, I have to cut down
the
prop to 64" or keep the engine below 5500 RPM. The choice is
either
inefficient prop and adequate power, or efficient long prop
and not
getting all the power from the engine? Am I
wrong?
Buly
atlasyts@bellsouth.net
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