On the aluminum question, yes....its a big part of the reason why I can run slightly juiced pump gas and not pre-ignite. Pleaes note my altitude guys....5000 feet. Makes a big dif up here. By the way, the 500 HP goal is not set in stone....and definately not obtainable at 5000 feet. Rather a comparable engine at sea level would or could make about 500 HP.
Remember, I have ran this thing at 11.6 CR for a while now and it works without much issue. And, it is a toy, not a daily by any means.
My street bike is 12:1. runs on pump gas....CBR-945 RR world endurance engine....158 HP at the rear tire. She starts knockin at about 3000 feet. I can flog that thing all day with my wife on the back....again, I'm up in the high Sierra's.
If I was at sea level, this exorcise would not be happening.
Quick shopping looks like AFR most $$ then Brodix and then Dart being the lease expensive. I see lots of Dart Pro 1's on e-bay for around $1040. The flow numbers look impressive....any thoughts?