What is Stage II?
- Thread starter LTNG KLLR
- Start date
Stage parts are the Buick equivalent of the Chevy "Bowtie" parts. They're heavy duty, factory produced blocks and heads meant expressly for racing. They were used in the mid 80s in Indy cars, and until about 2-3 years ago for various forms of circle track racing, competing quite successfully.
The Stage 1 and Stage II blocks are heavier, high nickel castings with a number of changes aimed at making them survive higher horsepower. The latest Stage II castings featured 14 head bolts per bank, 4 bolt mains with crossbolted front and rear caps, bores shifted to make them on-center and eliminate rod offset, dry sump oiling, etc. They have made in excess of 1400 hp in turboed form.
The Stage II heads were a totally fresh design; they share no parts with the stock heads and have ports larger than a lot of BBC heads!
They were a crucial part of the buildup that allowed 274 ci V6s to make 525 hp in a carbureted circle track car that would live for 500 miles and embarrass V8s with 50+ ci more displacement.
See www.gnttype.org and look at the block and head guides for pictures of the various Stage blocks and heads.
Interestingly enough, there was a Cobra kit car at Reynolds this weekend with a carbureted Stage II motor in it (basically a Busch GN motor, oddfire). It ran 10.80s on a single 4 barrel carburetor, normally aspirated! The motor made 475 hp on the dyno.
The Stage 1 and Stage II blocks are heavier, high nickel castings with a number of changes aimed at making them survive higher horsepower. The latest Stage II castings featured 14 head bolts per bank, 4 bolt mains with crossbolted front and rear caps, bores shifted to make them on-center and eliminate rod offset, dry sump oiling, etc. They have made in excess of 1400 hp in turboed form.
The Stage II heads were a totally fresh design; they share no parts with the stock heads and have ports larger than a lot of BBC heads!
They were a crucial part of the buildup that allowed 274 ci V6s to make 525 hp in a carbureted circle track car that would live for 500 miles and embarrass V8s with 50+ ci more displacement.See www.gnttype.org and look at the block and head guides for pictures of the various Stage blocks and heads.
Interestingly enough, there was a Cobra kit car at Reynolds this weekend with a carbureted Stage II motor in it (basically a Busch GN motor, oddfire). It ran 10.80s on a single 4 barrel carburetor, normally aspirated! The motor made 475 hp on the dyno.
Ron Tarabori
New Member
- Joined
- May 25, 2001
Hi Kendall, The Cobra was probably Bob Mustics from Georgia. It is a odd fire ASA motor that I sold him. He used the dish 9 to 1 piston and put a set of Busch heads on it so it probably is still only about 10.5 or 11 to one. Makes a lot of the big blocksf and side oilers scratch their heads. Ron
