The big one is like the Great Planes Ammo 36-88-1280
http://www3.towerhobbies.com/cgi-bin...?&I=LXLXA1&P=7 and it is 88mm long. It is a beast of a motor and I punished 2 of them and I'm saving the third for something mild. The first one I tried with 36 volts and it lasted longer then I thought. The second one I kind of shorted with a mounting screw that was just a tad longer. They have the strongest magnets I've seen in a brushless motor.