In the search for more details on the rotax performance with a variable pitch
prop I have borowed the Diamond Aviation Katana handbook.
Diamont have done a lot of testing on the 912 and there are a lot of details of
engine output, manifold pressure and fuel consumption at various power settings
and altitudes for the 912.
Some of the numbers are surprising e.g. It is recomended not to run the engine
below 4300 rpm to avoid accelerated wear. The normal cruise RPM is advised as
5450 RPM (prop 2400). For fast cruise use 5450 RPM and open the throttle to the
maximum manifold pressure for that altitude, then reduce the manifold pressure
by 0,7 inch!
I was nervous running my engine above 5000 RPM before I read this handbook but
it seems that the 912 is extremely robust and loves these revs.
It makes good reading for all of you with variable pitch props.
Best regards
Barry Tennant
|