os 91 on a spitfire h9
08-23-2008, 07:36 PM
#1
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Join Date: Feb 2006
Location: Gentry AR
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os 91 on a spitfire h9
I have a os 91 surpass it seems not to pull my spit fast enough tried a 15x8 wood and then a 13x8 apc that was a little better. Motor has good compresion and all runs pretty good just wondering any one have a better prop sugestion
08-23-2008, 09:34 PM
#2
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RE: os 91 on a spitfire h9
Rule of thumb, longer prop smaller pitch= slower speed but more torque or pull. Shorter prop with A bigger pitch= more speed. You just have to try props until one of them works the way YOU the pilot likes. Just make sure you keep your four strokes in there working RPM range so you don't float the valves. Finding that special prop is A lot of work and fun.
