At 08:30 PM 6/12/2016, you wrote: >Mine cruised at 155mph with a 54X54 and 2700CC at 2950RPM. ++++++++++++++++++++++++++++++++++++++++++++++++++
A 54 inch pitch propeller running at 100% efficiency would only make 151 mph at that RPM. Either your tach or ASI were in error or my math teacher in a country school was in error. 54 inches X 2950rpm = 159,300 inch per minute X 60 minutes= 9,558,000 inches per hour /12 = 796,500 feet per hour / 5280 = 150.85 mph Larry Flesner
