I'm speaking theoretically. But there is a guy in Canada with a SuperSTOL/914/Catto combination and he is pitched such that on takeoff he must keep the nose pretty high or he will over speed the engine. Perfect for getting all available horsepower for takeoff and climb. He gets 90 mph at 5500 rpm.
I have changed the prop setting from 13 Deg to 14 Deg. It is much better. At a density altitude of 7500 feet I get 37-38 inhg. I climb out at around 1000-1200 f/min and can cruise at 5000 rpm at around 27 ingh at around 115 mph. Seems to be the best compromise. The take off roll did not degrade from 13 to 14 Deg and the engine does not over rev.
I have a 2010 Kitfox with 912 ULS with a Sensenich ground adjustable prop I bought last year and I have never really adjusted my prop before . I just returned from OSH and prior to my trip the prop was set at its lowest setting for short takeoffs . I changed the adjustment pin to #3 (0 being the lowest) . Static was around 4800 RPM and flat cruise was about 5200 with a good speed increase to over 110 MPH. This lower RPM concerned me about stressing the case so I dropped it one notch to #2 which increased the static over 5000 and max cruise to 5500+ . Would it be OK to run the #3 for long trip then change it back?
If 5500 is max normal operating rpm what is the correct cruise RPM ? Can I run it at max for long periods of time or should I run it a bit lower? On the same subject my green operating rpm goes down to about 4000 is alright to cruise around at 4000?
If you have WOT at level flight set to 5600 where is a good cruise RPM? Can you cruise at 5500 with out hurting the engine . I like 5200 or so. In the same subject is it ok to cruise at 4200?
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