Yeah, there's a lot of good info scattered around this site.

Quote:This might be a new question, I don't recall that it's been asked before.

I would think that none have an advantage over the other. All these engines will respond to supercharging equally well, and packaging the gear will be nearly identical.

Of course, there is an advantage with or without supercharging: the A15 is 25% larger than the A12, so you'll get more power over the usable RPM range with the A15.