I've played around with, experimented with and done the mad scientist aproach to alternative energy since I was in my early teens (20+ years now)
I've read about countless alternator modifications on the internet over the years and have actualy tried many of them too. The ones I have tried and that did actualy work are what I tell others about. Still there are limits to the actual practicality of these modifications! They do work but are often best suited to specific application uses.
for experimentaion purposes taking a cheap and well used device and modifying it for a specific application is often way cheaper than buying a new unit and hoping you dont accidently kill it the first time you try using it in that modified condition.
Once the sacrificial devices prove its a vaiable design consept then spending money on a new device to do the job become more justifiable.
Buying used alternators from the truck or auto salvage or scrap yards for $10- $20 each and killing several of them in the name of research does not hurt the pocket book so much as buying a brand new $500 unit and watching it die and not having any waranty coverage because you opened it up and modified it!
I do a fair amount of my work specificaly around larger construction equipment and have had many chances to work on, repair, and replace larger than normal alternators. But I dont know all there is to know by any means.
Had I not been in the right place at the right time I may very well could have never found out any of this information relating to the larger application alternators!
I got lucky and fixed one once for a friend and it sort of just snowballed from there.
I just know what I have done and found reasonable to do and work with.