Engines create tourqe as they run (for reasons which I will not bother to explain). The larger the engine, the more tourque. The larger the airframe to the ammount of tourqe will deaden some of the effects.

Its all a balancing act performed by you, the tourqe of the engine, and the airframe. Thats why on takeoff with almost every plane you will need to hold a little rudder to compensate for the tourqe. Some planes have right and/or down thrust built into the firewall to compensate for the effects of tourqe during flight.

Follow the plans and you will be fine [8D]