Copterdrvr,

The K&B makes about 1.32 HP at about 13,000 RPM. Right?

Spinning an 11x7 APC at 13,000 RPM static required 1.46 HP (according to the Reivers prop calculator). So the K&B will spin it at about 12,500.

Unless you intend to use this engine to fly a 15 MPH Goodyear Blimp model, which will allow the engine to unload very little, the 11x7 is TOO SMALL for efficient use on this engine.

Any medium speed, sport plane will require the engine to be propped to a static, ground RPM of 11,500 RPM, so it can unload in top speed, level flight to the 13,000 RPM of maximum output.

The props which closely answer to this are the 12x6 and the 11x8.

The 11x7 will unload to about 14,000. Read my previous post, as well as this thread:
http://www.rcuniverse.com/showthread...+to+prop+a+.60

To see why this is not good..