Guy's when you  are trying to determine which engine has the most power, not R P M, and both engines are the same, what method do you use?

  I am going to use the same prop, fuel and glow plug and run one right behind the other so that weather conditions will be as close as possible.

 I hope that I made myself clear on this, and thanks a lot...

  And the engines will be run on a test stand, not on the model..

Gil unless the differences are pretty great and you don't have equipment to measure them scientifically then the laymen's way is to simply fly them both to feel subtle differences.  This would also take into account flight loads which won't show up on the test stand. Looking and listening on the bench won't tell you too much. (Unless one pulls the test stand over and the other doesn't)

Dave

     Hi Bootlegger:

      Now I ain't very smart, but if one has various engines to compare for a power rating, would not using the same prop(s) and taching them determine which engine had the the more, most power?

       I think that force times distance divided by time equals power. Would you not have enough information to draw a conclusion?

       I have a site on my favourites that presents power ratings for almost any prop and what the airspeed is when using the rpm,pitch and diameter of each prop.  This chart opened my eyes when I compared Diesel engines to glow engines as far as HP was concerned!

                                                                         Stay well,

                                                                         Frank