[frodus]

does the motor sink heat to the case? yes.

Can adding heatsinks cool it down, yes, but only a few degrees. The heat you need to get rid of, is in the copper windings. By the time it gets to the outside of the motor, it can be too late.

Blowing air on motors helps, many people do it with eteks, but they wear quick, and some people have problems with them coming loose inside the housing because of the heat.

Best thing to do is get the RIGHT motor for the job, don't halfass it. Don't spend 1/4 of the money just to get a motor that could be overpowered for 5 min to move the car. Get the motor that can move the car for 45min or an hour without melting into a pool of metal.

Its all about duty cycle. Sure, it may handle 600 amps.... for like 5 seconds.