If you are good at math... the formula is HP=Torque X RPM/5252.

You should use a prop that lets the engine run about have way between the maximum torque rpm and the max hp rpm.

In your example, you would only be able to calculate the toque at 16000 rpm.

In spite of what the trumped up manufactures figures say, This engine would be happier to turn around a maximum wide open throttle speed of 12000 on the ground.

I would be willing to bet that the engine would not make it to 16000 with any kind of prop on it. That was probably with just a flywheel on it with an electric fan to keep the motor cool?

Look at www.rcfaq.com and see what rpms different engines turned with which props.

enjoy,

Jim