i know the MoCo used to have the steel motors, but were having damn problems with them. now i hear, the aluminum is better, so whats wrong with the old damn steel motors?????? please answer me???????
in a word, weight. you can loose 40% of the weight using alluminum vs steel.
Aluminum dissipates heat better than steel but I never had trouble with my '55 Panhead. Maybe it was colder temps in the 1970's.
Aluminum has better cooling properties, they are lighter, they are more forgiving with heat, Most importantly, aluminum expands and contracts better without the threat of serious stress fractures.
