500 V-twin converted to supercharged 250cc
 

This is probably old news round here, but:

a. Introduction « crecca

Suzuki GS500e v-twin converted to a supercharged 250cc (using 2nd cylinder as compressor).

Doesn't look like it was quite finished (so far) but I'd love to know what efficiency improvement he would have seen.

Sounds a lot like a Scuderi Engine: Scuderi Engine - Wikipedia, the free encyclopedia

I think he makes that comparison - I like his backyard take on getting there.