RE: Looking for a fast airframe
The engines are mounted on a beam, but it is an extremely tight fit. The spinner contours exactly with the shape of the fuze with only a 1/16" gap. Mounting of the firewall is very important.
They are louder than a Q500, because the engines are tuned to run at 23,000 rpm versus a Quickee at 19,500. However, for a sport plane in Europe, I would suggest running a Q500 motor on the plane. You will still get 175 MPH with that engine, and you will have a throttle barrel, rather than the Q40 with open venturi.
I can post pictures if you want.
Gary, Which AT-6 did you have? The wing kit mentioned above, is definately sport scale, and was made to go faster. The nose is not as big and round, and the wing is thinner than scale. For a .40 sized warbird, this is the fastest we've found up here. With the same engine, its a bit faster than the World Models Mustangs.