Crazy Big Block questions
Thread Starter
Instructor
Joined: Jun 2008
Posts: 127
Likes: 0
Crazy Big Block questions
I admit, I don't own a C3 but you corvette guys are really the only group that I care to get my information from. I have a block from a 1971 Chevelle 396. It has been bored to 402. Stock internals besides the bigger bore. I want to build a motor for the street around 500hp at the crank. I have no clue what heads I should use or even what cam, intake or carb I should start with. I need to be able to find the parts I need at a decent price. I would like to find a set of factory cast heads that I could use with different springs and maby some valve work. I have been looking at a cam with a lift around .544" and a duration around 292*. It will be a 4 speed and does not have power brakes but I will still have to drive it on the street. Any help you guys and gals could give me would be great. Thank's
Phil
Phil
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Try www.teamchevelle.com
Go to the forums, then to the Performance section. Most of those guys are BBC gurus and will have tons of info on combos for various BBCS.....
But in my opinion, you will need some domed pistons to get some compression in it, that Comp 292H cam you are talking about is junk.....you need to get something matched to your combo...A lot will really depend on the heads/intake/compression you choose to use.....
Intended usage, vehicle weight/tranny/gearing etc will all play a role as to what cam you pick....
Do your research and do it right the first time...
Go to the forums, then to the Performance section. Most of those guys are BBC gurus and will have tons of info on combos for various BBCS.....
But in my opinion, you will need some domed pistons to get some compression in it, that Comp 292H cam you are talking about is junk.....you need to get something matched to your combo...A lot will really depend on the heads/intake/compression you choose to use.....
Intended usage, vehicle weight/tranny/gearing etc will all play a role as to what cam you pick....
Do your research and do it right the first time...
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
500 ponies from a 402 BB is fairly easy with aftermarket heads. I wouldn't mess with head original castings.
Some aftermarket oval ports will do the job. AFR has some new O-ports,..295cc that would work great here.
I'd also go with a roller cam in the 240 @ .050 range.
These two items, plus the usual carb, intake, and headers, will get to 500 HP, and be very driveable.
Good luck.
Some aftermarket oval ports will do the job. AFR has some new O-ports,..295cc that would work great here.
I'd also go with a roller cam in the 240 @ .050 range.
These two items, plus the usual carb, intake, and headers, will get to 500 HP, and be very driveable.
Good luck.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 127
Likes: 0
500 ponies from a 402 BB is fairly easy with aftermarket heads. I wouldn't mess with head original castings.
Some aftermarket oval ports will do the job. AFR has some new O-ports,..295cc that would work great here.
I'd also go with a roller cam in the 240 @ .050 range.
These two items, plus the usual carb, intake, and headers, will get to 500 HP, and be very driveable.
Good luck.
Some aftermarket oval ports will do the job. AFR has some new O-ports,..295cc that would work great here.
I'd also go with a roller cam in the 240 @ .050 range.
These two items, plus the usual carb, intake, and headers, will get to 500 HP, and be very driveable.
Good luck.
Melting Slicks
Joined: Jan 2003
Posts: 2,877
Likes: 13
From: Doha
St. Jude Donor '08
If you'll go with aftermarket heads, then make sure they have the exhaust posts on the stock location, most of the aftermarket heads have the ports rised between .2 to .4 in. That would cause some problems to fit the exhaust manifolds (or headers) in a Corvette.
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
I'd sell the 396 block and snag a 454. It's much easier to reach your goals with the bigger bore/longer stroke engine than with the 396. You could even keep the crank and rods and build a 427. That's an engine most of us Chevy guys will always associate with a Corvette.
