Hi.

I purchased a tachometer (GloBee IntelliTach) to check my prop's RPM. I had a Top Flight 12 x 6 Power Point prop on an OS .65 LA engine. Running full throttle, the RPM topped out around 11500.

This weekend, I changed props to a Master Airscrew 11x6 Beechwood Propeller. I anticipated the RPM to increase, but it top out around 11500 also.

Anyone have a quick tutorial on RPM and prop sizes?

1) Is there a way to calculate the power of the prop size/pitch combined with the RPM? (for example: a 12 x 6 prop and 11500 RPM equal XX amount of thrust)
2) I would expect a smaller prop's RPM to be higher. Should I be looking for 100 RPM variations or will the variations be as small as 10 to 20 RPM?
3) Or does anyone know the normal range of RPM on different motors or prop sizes? Is 11500 normal?
4) Will fuel have a significant impact on RPMs? More nitro equals more RPM?

Etc. etc.....


Thanks.