How do I know if my Hartzell Prop Gov is Compatible with a Hartell Aerobatic Prop?

[marky]

I'm rebuilding my IO-540 C4B5 for my DR-109 (2 place aerobatic) . My engine came from a Piper Aztec,with Hartzell Prop Gov Model F-2-86. How can I figure out if my prop gov will work with a Hartzell aerobatic prop - like the one off an S-2B? thanks! check

[rleffler]

The obvious answer is to call Hartzell. Ask for Les Doud, he's usually pretty helpful.

[WLIU]

From my recollection of looking at the parts book, that governor will not work with an aerobatic prop. Aerobatic propellers have counter weighted blades so that if the oil pressure drops off, the rpms go down, not up. That protects the engine. The Aztec props are feathering and non-counter weighted. They work opposite to an aerobatic prop.

The Pitts S-2B Type Certificate Data Sheet (TC A8SO) shows a Hartzell F6-59Z prop governor. I understand that the PCU-5000 is newer and better, but that assertion is second hand.

Best of luck,

Wes
N78PS

[marky]

Thanks to Bob and Wes for their replies - my dilemma of determining if my stock IO-540 governor from use on a Piper Aztec would work with an aerobatic prop. I went to TIFFINAIRE inc and had tech discussions with their rep Gary Bibler. The F2-86 gov I have can be converted to the -59Z governor used with compact counterweigthed aerobatic props. The governors all use similar and acceptable cores. What remains is whether my Aztec prop governor is airworthy - worth using as a core for the rebuild and mod work. I never realized how expensive prop governors are - cost ranks right up there with anRS5A fuel servo! thanks again for your help. marky