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Greg, its always hard to compare props from
different makers, but just for reference, I fly a 13B (est 180 HP) with a 74x88
two blade Performance Prop off an RD1C. Even with this size prop I can
easily get 6000 -6100 static rpm. Since the Renesis should produce at
least 20 HP more, I would sure have to wonder whether a 68x80 would be enough
prop.
But, then it also depends on what you want out of
the prop. I am not interested in high end top speed as I seldom fly faster
that 180 MPH TAS. However, I do like to get in and out of small grass
fields over tree lines smartly. A larger diameter prop disc ends up
accelerating more air mass (and by reaction - the aircraft) faster than a
shorter diameter prop. Now, on the top end a smaller dia prop would let
you wind the engine rpm higher thereby producing more engine power thereby
producing more speed.
Just though I would pass this along for you
consideration.
Best Regards
Ed (Still waiting to launch - day 5 waiting
for clouds to lift so I can make Sun & Fun)
----- Original Message -----
Sent: Monday, April 07, 2008 6:37
PM
Subject: [FlyRotary] Prop selection
Anyone had any experience with Prince props. http://www.princeaircraft.com/
They recommend a 68x80" (2 blade) prop for my RV8. The web site claims better
efficiency so a shorter prop can be used, which suites me. I was quoted
$1646 for wood and $2185 for carbon fibre I think that includes crusher plate
and bolts. They're quoting 15 week delivery which is better than some
I've heard of.
Greg
RV8 Renesis
RD1C
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