Hey guys. I have sought your help in building up my 68 Firebird and your knowledge has been great thus far. I recently bought a low milege 1967 400ci engine with an Ohio Crankshafts 455ci 4030 crank, 6X Heads and forged AutoTech pistons. The motor came with a Schneider 290H cam and a Hurricane intake. The motor was originally setup for a high RPM application and I want to make it more street friendly. It's going in my 68 Firebird with a Tremec 3550 trans (low 3.27 first gear) and 3.42 reared gears. I already have a Performer RPM intake and am looking for camshaft recommendations. The car it a street car that will never see slicks, but it is only driven on once days and driven hard. I's like a real choppy muscle car idle as well, and already have a vacuum canister for added power brake support.
Sounds like the begining of a great motor. 6x-4 or 6x-8 heads?
I had to look up the specs on the Schneider cam. If you like a choppy idle and if lower vacuum is not a problem why not run with the cam you got. I/E @.050....Lift w/1.5 LSA 220 232 0.485/0.510 110
Did you want to run a Hydralic flatt tappet or Roller cam?
The motor is already together and has been dyno'd using a Hurricane Intake and the 290H Schnieder cam. It made the following power:
RPM TQ HP 2500 457 218 3000 461 263 3500 478 318 4000 470 358 4500 451 386 5000 414 394 Max TQ @ 3500 was 478 Max HP @5200 was 397
I just bought the motor from the guy who had it built, but he was planning the build for high RPM's and went with the Hurricane intake. The confusion thing for me is that this cam seems fairly tame, but Schneider's website states that the RPM range is 2800-6400. I am planning to use a RPM intake and want to get a good cam to match everything else. Do you guys think this cam would work with the heads and RPM intake? I also thought about retarding this cam a little to drop the RPM band as well.
I would have to agree with just throw it in and drive it. If for no other reason then to get a base line of what you like or don't like with that cam but the dyno looks pretty good to me. I would not be too worried about what the cam specs said. looks like a heck of a flat torq curve. The duration numbers look right in line for a street cam in a 455. I would think with a good set of headers to complement the 110 lsa you will be pretty happy with it.
Like I said I ran a very similar combo in a heavy GP and it ran great. However the same motor and heads with a different intake, q-jet and LBM ran terrible.
I would do some testing with the two intakes since you have them. My best guess would be the Hurricane intake will give you more upper RPM HP since its a single plan and the RPM would give you a little more low end torq since its a dual plan. My just end up being personal preference on which one you like. The Hurricane intake has no exhaust cross over so it may be a little more cold blooded on starts but less likely to cause a gas boil over and hard starts.
