Just have an "engine torque" question. I'm in the process of builing a .60-.90 size Top Flite Corsair and noticed the firewall is angled to allow for engine torque. However, on my .60 size ARF's and .40 size planes there is no angle in the firewall. Why is this? Is there only a need for the angled firewall on planes with larger engines? The natural torque (pull) of an engine is to the right...correct?
Thanks,
Pat

Generally, RC engines rotate clockwise when viewed from the pilots position. (or CCW when viewed from the front when you are starting it). SO the plane tends to roll to the left due to torque and p-factor. So many RC plane designs call for one or two degrees of right thrust. It can be builtin to the firewall or the firewall can be square and you can build in the right thrust on the motor mount. Quite frankly, it doesn't really matter that much for everyday sport flying on most planes.

Pat,
It's as DMc stated that the 'pull' is to the left especially on tail-dragger's. You can test the in-flight affects of torque by pulling your plane straight up as it's flying away from you. If it does not fall off toward the left wing, then you have the correct offset and rudder trim. If the plane wants to roll, you've corrected torque with the ailerons. Once again, it's not critical on sport and trainer planes as it is on pattern or IMAC.