I was waiting to see in the comments EXACTLY this question: There is no way to dump this heat. 1000hp? Yeah, maybe for a few seconds, even with oil coolant pumping through there. Then how to dump the heat from the oil. And further thinking, if they ever get this to be a hub motor, how in the world are they going to pump coolant through 2-4 hub motors and then to a radiator that can dump that rate of heat rise, especially since oil is a lousy coolant (relatively speaking).

Those could be answered by large radiators or the like - when outside the ‘has to be dense’ path. The issue the motor has is exactly that it needs to be dense - and has a lot of power going through it.

Liquid cooling at least for now should work - as long as it stays below the flash point of the liquid I guess.