82/44 rpm?

[Roger Gross]

What RPM are 82/44 users getting at full throttle? We are running a new O-320 with new ported and polished cylinders and Sutton exhaust that should be around 170 hp, but are only seeing 2450-2500 at full throttle. Is this normal with this prop?

 

[jwflys]

With a recently overhauled O-320, Sutton Exhaust and Borer 82-44, I hit 2700 RPM easily when leveling for cruise. I throttle back to break-in power setting.

A friend recently found his tach was reading too low. Might be worth spending time verifying yours. My static numbers are as specified in Borer STC.

 

[windy]

When I had the O-320 (150 Hp) on my PA-12, I'd turn just over 2700 rpm straight & level at 6000 msl on Borer 82-44 prop. Tach was verified during prop balancing. Static on the ground was about 2450 rpm at full throttle.

windy