bob27s

My Feedback: (19)

Timing change is not going to help a great deal .... once you get to a point, airflow through the carb/crankshaft becomes the limiting factor on the engine. All a timing change is going to do is shift the torque curve a bit.

You noted an 8.8x8.5 approaching 20K rpm.... thats darn good in any book. I'd not expect much more.

You might want to try taking a 8.8x9.25 and clipping it down in diameter to 8.25" to get the rpm back.

In any case, it is very unlikely the aircraft is going to perform much over 160 mph.