Yes the Kougar has a wing that resembles a park bench in it's cross section for sure! That said it's one of my favorite flyers as is anything designed by Claude McCullough. Somehow I get more personal satisfaction from making one run in the 120 MPH range then throwing up my electric Surprise 9.

Yes it's a waste of energy <like discharging one of my lipo's to storage voltage on Sundays> but I truly enjoy it.

In all honesty I think as draggy as the Kougar is, and with my RPM being what it is, Ill stick with a 10" diameter prop. Me thinks you would have to spin a 9x? awfully fast to get this brick moving.

Thanks for your help. It sounds like I am/was confusing volumetric efficiency with what I assume is the compression of the motor. I assumed at higher RPM the pipe injects more fuel/air then at a lower RPM, changing the compression and efficiency of the motor.

Tommy D