BarracudaHockey

My Feedback: (11)

First, engines have RPM bands where they produce their most power.

Pitch (the second number) is the distance in inches an prop will advance through the air in one revolution. (its theoretical due to efficiency issues but it works for comparison)

The prop range is the range of props that will keep that motor in an RPM range thats safe for that engine and in its most efficient power band (again, give or take, there are exceptions to everything)

The higher the pitch the faster the straight line speed but the less pull on uplines.

Lower pitch, more "grunt' but less speed.

You generally adjust the diameter in that range to get the speed you want and the load that the engine operates best in.

As others have said, its a combination of the engine, the airframe, and pilot preference to which prop is "best".

Falcon Props brings a board full of props drilled for most popular engines in various sizes to big events, you can try different props. THAT my friends is the way to sell props IMO

Edit: Another generalization but an 8 pitch would probably be thought more as a 3D prop, a 10 pitch a sport or general prop, and a 12 pitch a speed (or warbird) prop. Some manufacturers like vess use letters, A, B, and C would be approximately 8, 10, and 12 respectively, though they have more pitch near the hub where the prop has the most torque with less at the tips where its less efficient.