I'm running a box-stock (formerly a diesel, but we won't go into that) Tower 40, on an overweight profile. It does have a CL venturi. Turning an 11 x 5 APC around 9,500, 10%nitro, it is running 5 sec laps on 64 ft lines and serving very well in a 2-cycle all the way. The K&B 4011 is a favorite engine and I am building an airplane for one as we speak. It is a little bit more powerful than the Tower, I think.

Jim