Originally Posted by
Flyin'Dutch'
Long time ago and old thread.
But to answer the question, I don't know how the derating was achieved. Clearly by limiting revs but how, I am not sure.
Yes, the Maule with its constant speed prop will have had the governor max RPM set to something below 2700rpm - probably 2500. A standard 8.5:1 compression parallel valve O540 will be good for 260hp at the full 2700rpm redline. Only paperwork stopping you adjusting the governor of your Maule to get the extra 200rpm and extra horsepower - prop limitations aside.