The Align motors have a fan built in. However it only helps if the motor is running
. In a heli that isn't a problem, but for us car/truck guys who aren't constantly moving the fan doesn't help much. I don't think a liquid cooling system will help enough to justify the extra weight because the windings are internal. They have no direct contact with the can, and the rotor is in the way, too. Mounting a fan or two so that they blow into the slots in the side of the can would be best, IMO. Or if possible rig a fan to blow into the front of the motor through the motor mount.