I'm trying to pick brushless motors for all my planes (P-51D, Super Cub, Easy Star, Fledgling & Cermark electric glider). I'm lookin at some on E-bay and the way I am figuring out what will work with each application is to figure out the wattage output/draw for each motor, for instance one outrunner is rated for 3 cell LiPo (11.1v) and 16a constant. That would add up to 177.6w? (11.1v x 16a). They rate it at 250w so I assume that would be at max current @ 11.1v. The RPM is 3200K/v. I don't know if I should factor that in.

Another motor is rated at 20a max, 6-18v (up to 4 cell LiPo?) and 1050Kv. Being consertive I would figure watts using 11.1v x 16a =177.6w. Same as above but lesser RPM.

One I like is 980K/v, 30A max and 6-22v. That would be a lot of watts but low RPM.

Am I on the right track? Please feel free to correct me where needed. I am trying hard to establish an easy formula to caculate electric motor power across all brands and even from brushed to brushless.

Thanks.