The insides are absolutely cavernous on these motors, so an active ventilation approach like Arlo1 did with his X5 has huge potential. Plus with proper exhaust holes at the very perimeter could mean tremendous flow even without going active due to the large diameter.
My approach would be a combination with fans block the spokes except for some fans sucking air from one side and putting both intake and exhaust holes in only one side cover. The purpose would be to suck air to the closed half, so it's return flow would be through the magnetic gap and out the exhaust. I'll document mine if I ever get a controller that can push Hubmonster hard enough to get hot.
John
