jett 60
Prop size was 9x10 down to 8.5x7.5, fuel 15% wildcat with 20% oil, rpms varied so much it was hard to get reliable readings. With pinching the line rpms would come way up and get on pipe then sag back down. With leaning the engine it would come on pipe all at once and rpms went way up but then it would lean out and fall back down. Could not get a good setting where it would run at right rpms for it to unload in the air. The pipe was made by jett and supposedly tuned for a 9x10 apc.
The head bolts kept coming loose also. I have sent them back and will see if he can help. My feeling is it wasnt broken in with the bigger props and the smaller props turned too fast