Paul wrote:

Hi, fellow rotary enthusiasts....I am looking for information regarding the best prop dia and pitch selection for my SQ2000 canard.  I presently have a 3 blade 64 x 78 Performance wood prop.  With
my new manifold, I am now able to get a static rpm of 4800 rpm's (The second attempt gave me 5000 rpm's, and the third attempt gave me 4800 before rising temperatures caused me to discontinue
testing). I have a Ross 2.19:1 PSRU, so I figure I got between 2191 rpm's and 2283 rpm's with a 64 x 78 prop.  Anyone care to decipher these results?
     I got an email from Ron Gowan, and he was using a Performance 3 blade 62x72 prop with a 2.19:1 redrive and he stated that he was able to do 195 mph at 1500 feet altitude at 6000 rpm's.  I doubt
that my prop would unload that much in the air (to get 6000 rpm's).
     Ed Anderson, I believe was using a 68 x 72 prop, and Perry Mick's new prop is 62 x 68.  Just wondering if my 64 x 78 is too much prop, or?
     I should mention that my primary concern is for a good cruise prop.  I don't care about a climb prop....I figure I spend a lot more time at cruise than climbing, so I would like the optimum
performance to enhance my cruise performance.
     Unfortunately, on my first flight the engine was not developing adequate power (max 4200 rpm's), so I can't provide any flight data for this prop.  Just trying to find out what prop sizes
others are using that have aircraft designed for speeds around 200 mph.
     My engine is now running considerably better and developing more power after I changed intake manifolds, so I would like to try to match prop to engine and aircraft, of course.  Thanks in
advance for all replies and suggestions.  sincerely,  Paul Conner, rotary powered SQ2000 in Mobile, AL

All depends on how much HP you have Paul. All those people you mentioned including yourself
have widely different intake manifolds. It is not like every body had an O-360.
Before you make a decision I think you should make some top speed runs and note
the RPM.

Paul Lamar
 
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