I have been trying to break in my engine by running "hard", I thought, at 2550 rpm.
This is a 160 hp 0-320-B2B with Leading Edge exhaust and an 82/44 Borer prop. Recently I installed a manifold pressure gauge and was startled to find that 2500 rpm results in only 21 in. Hg manifold pressure which is about 63% power.
In discussing this with Darrell Bolduc at Bolduc Aviation Specialized Services, Inc, he told me that I must run 24 in. Hg to seat the rings. That turns out to be 2750 rpm, 83% power. So I am running at that rpm until the rings finally seat .... if I didn't already screw it up. Just thought I would publish the following info so that others with Borer props will see the manifold pressure / rpm relationship also and not make the same mistake.
N18SY Manifold Pressure.jpg