Header size for a 454 SMALL block
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Joined: Apr 2007
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Header size for a 454 SMALL block
Thinking about having a 454 SMALL block built for my '78 from T and L Engine Development. I want something with BIG cubic inch and torque that will bolt right in to my vette without any conversion on drive accessories, etc.
My question is this: I'm going to be using Hooker Sidemounts/Sidepipes that are for a "small block". At 1 7/8", do you think that will be too restrictive for a 454 c.i. pushing 600 h.p.???
My question is this: I'm going to be using Hooker Sidemounts/Sidepipes that are for a "small block". At 1 7/8", do you think that will be too restrictive for a 454 c.i. pushing 600 h.p.???
Safety Car
Joined: Aug 2001
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Thinking about having a 454 SMALL block built for my '78 from T and L Engine Development. I want something with BIG cubic inch and torque that will bolt right in to my vette without any conversion on drive accessories, etc.
My question is this: I'm going to be using Hooker Sidemounts/Sidepipes that are for a "small block". At 1 7/8", do you think that will be too restrictive for a 454 c.i. pushing 600 h.p.???
My question is this: I'm going to be using Hooker Sidemounts/Sidepipes that are for a "small block". At 1 7/8", do you think that will be too restrictive for a 454 c.i. pushing 600 h.p.???
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
If you read up on header science you can determine the length and diameter of the primary pipes and collector length/diameter. I really don't believe that side pipes have correct primary length in mind when they are built.
A smart person would install really high flowing spread exhaust port aluminum heads on a 454 small block
typical small block heads are kind limited to @1 3/4 pipes because of the bolt pattern. you can use adapters to install out to 2 1/4 pipes, but the correct solution is to buy spread exhaust port heads
To make 600 hp requires heads that flow over 300 cfm intake and @ 220+ exhaust. I use Dart 227cc heads advertised at 314/230 CFM If I didn't already own the darts, I would really look at the Brodix -12's with 272 cc intake ports. I think that they flow over 360 CFM.
you can't think small block when you are over 430 ci
A smart person would install really high flowing spread exhaust port aluminum heads on a 454 small block
typical small block heads are kind limited to @1 3/4 pipes because of the bolt pattern. you can use adapters to install out to 2 1/4 pipes, but the correct solution is to buy spread exhaust port heads
To make 600 hp requires heads that flow over 300 cfm intake and @ 220+ exhaust. I use Dart 227cc heads advertised at 314/230 CFM If I didn't already own the darts, I would really look at the Brodix -12's with 272 cc intake ports. I think that they flow over 360 CFM.
you can't think small block when you are over 430 ci
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Big problem is finding headers that fit our cars bigger than 1 3/4". The Hooker side pipes are the only ones I am aware of in 1 7/8 and they also make the only normal header in 1 3/4". There just aren't any out there that fit our C3's. 
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Headers or Motor?
It will most likey need adapters at least.
Harry P. Hunter
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Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
http://www.schoenfeldheaders.com/sbflanges.htm
I personally had to cut budget corners and I am using my old heads and Hooker super comp 1 3/4 with the flanges hogged out to somewhat match my monster Dart head exhaust ports. I went for three inch exhaust right off the collector to not cause a HP restrictive exhaust system
Le Mans Master
Joined: Apr 2007
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From: Graceland in a Not Correctly Restored Stingray
Bear in mind that the bigger your primary tubes (in total volume) the further up the RPM scale you're going to push peak torque. Too large, and your torque curve will tend to have pronounced spikes and valleys. Also, your muffler selection is going to be a significant factor.
That said, it's hard to resist just going with the Hooker sidemounts...
Last edited by TheSkunkWorks; Apr 26, 2007 at 02:32 AM.
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Le Mans Master
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From: Graceland in a Not Correctly Restored Stingray
As long as you have decent pipes and a relatively un-restrictive system behind it, you'll have gained the majority of what's available from improving the exhaust. If you're hardcore, I'm afraid you'll have to get this one engineered to get every last pony out of it.
Last edited by TheSkunkWorks; Apr 26, 2007 at 05:40 PM.
