Originally Posted by
barit1
Big Pistons Forever:
Yes, it's a nicety made possible by the fact it's a single-shaft engine running a single constant RPM. But if RPM varies, the HP varies proportionately. The equation for SHP goes like this, if torque Q is expressed in lb-ft:
SHP = Q x RPM / 5252
You are of course correct. I should have been been clearer in my post as a hp reading is easy to provide in a constant speed engine.
I find it interesting that a Cessna 210 I occasionally fly has a GEM engine monitor which among a bunch of other things gives a % of total horsepower value. This makes setting power easy as all the performance charts are presented in % horsepower.
A similar system would be easy to provide for a PT6 type engine but I guess there is not the interest.