How to compare gasengine size to outrunner ?

[What's_nitro?]

Well, if the motor can handle the power, then the rest is gearing. If you have limited gearing choices you need to find a motor in a certain kV range. Outrunners have plenty of torque, and happen to be in the same speed range as gas engines.

[speedy]

Would a kb45 xl motor with 800kv be enough ? I i drop the gearing from stock 17/57 down to 60/14t ? and run it on 8-10 lipos ?