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HP calcs for static RPM
Posted: Tue Aug 15, 2006 12:41 am
by Bruce Perry
Has anyone done the calcs for horsepower during static run-up? What I was wondering is what RPM with X prop yields Y HP's. I'm curious if there's some guidelines for output. Should it static to a certain RPM new and strong and then later when it's down on HP's due to fit, wear etc, what's the cut off?
With all of us on the forum I'd bet we could come up with some numbers if it hasn't already been done.
Just a thought.
Bruce
Posted: Tue Aug 15, 2006 1:48 am
by GAHorn
The handbook for operators of this engine has power curve graphs which depict the horsepower developed at various rpms. The Type Certificate for this engine/prop combination also specifies the static rpm. The two sources, when compared, show that the specified static rpm develops 118-120 horsepower. (Kinda explains that takeoff performance, eh?)
Remember, this engine only develops 145 hp at 2700 rpm at sea level. Good luck attaining that.
Posted: Tue Aug 15, 2006 5:49 am
by Bruce Perry
The handbook!??? why would I look there? I thought posting a question was way easier.
Thanks George I"ll dig out the answer book and have a look. I was thinking the performance was less than stellar last night as I took off from 2200 msl with 500lbs in passengers, full fuel and a blistering 350 FPM.
But for 115 ish ponies that's probably pretty good!
Bruce
C-170A, 1950