Thread: Alternators - what are the differences?

You'd be better off googling somthing like alternator design for the full story: but you are on the right track. Alternators are matched to RPM ranges - output at idle revs and max output at a particular rev.( ie v8/diesel suits other v8's, 6 cyl generally fits other 6's and 4's) The problem is more the physical design of the housing / mounts and line up of the pulleys. There's been a sucessfull transplant of a Bosch alternator into a RR V8. Legend has it that certain Magna alternators can fit TDi's. Updating series 1 and 2 alternators with a SIII is common.

If you provide a specific application, somebody might have already done a swap with somthing else.

changing the RPM rate is as simple as changing the pully on the front..

The key differences are

amps output and duty cycle at full load
the physical lay out of the mounting lugs
the physical size of the alternator itself (you seen the new 35 amp jobbies that fit on the palm of your hand?)
The electical connections on the back..

Ive changed the guts of one alternator from one vehicle int othe housing of another to get the second one working again on more than one occasion.

Have a read of this thread.. http://www.misterfixit.com/alterntr.htm
Alternators are very easy to repair all that really goes wrong with them is a blown diode. about a 50 c part .