How many pounds of presser is put on the gears, torque pounds per square inch, when the motor turns it will put out so much pounds per square inch on the gears that drive these nitro cars/trucks/truggy, and the bigger the motor the more pounds per square inch it will give. I just want a guestamation on how much pounds per square inch lets say on a VX.18 motor.

In physics, a torque (τ) is a vector that measures the tendency of a force to rotate an object about some axis [1]. The magnitude of a torque is defined as force times its lever arm [2]. Just as a force is a push or a pull, a torque can be thought of as a twist.