There are discussions about using alternators as motors on several different forums.
http://endless-sphere.com/forums/viewtopic.php?f=30&t=16328
http://www.rcgroups.com/forums/showthread.php?t=905411
http://www.rcgroups.com/forums/showthread.php?t=1123956&highlight=reem
In my opinion, the last one has the best concentrated info. The biggest problem I see in using an alternator as a motor is in finding a good reliable reasonably priced controller. Good luck
http://endless-sphere.com/forums/viewtopic.php?f=30&t=16328
http://www.rcgroups.com/forums/showthread.php?t=905411
http://www.rcgroups.com/forums/showthread.php?t=1123956&highlight=reem
In my opinion, the last one has the best concentrated info. The biggest problem I see in using an alternator as a motor is in finding a good reliable reasonably priced controller. Good luck