[jhautz]

I find with the Lehners, geared properly, they are very happy running around 40K rpm. Pick a kv that will get you around there on the voltage you want to run.

The Hi-Amp versions have 3 wires coming out the back of the motor instead of the 3.5mm sockets that the standard motors have on the back. If you you have a choice get the Hi-Amp IMO. Much more robust setup.

The plus side of a standard (non Hi-Amp) Lehenr is that the can be switched back and forth between Delta and Wye configuration by changing some solder paths on the back of the motor to run 2 different KVs. Kinda cool, but I still think the Hi-Amp is a more robust design. I actually solder wires into the 3.5mm sockets on the back of the standard motor so I can get rid of the 3.5mm sockets and run 5mm connectors on the ends of the short wires. 3.5mm connectors have no place in a high power set up.

I would pass on the new cooling versions. Its designed for airplanes and helis. It would probably just suck a bunch of dirt into the motor in truck use. Besides... If you run a reasonable rpm and gear it properly they run plenty cool.