Headers. Worth it or not?
Race Director
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From: Sunshine Coast, Queensland, Australia
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Le Mans Master
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So on the friendly dyno in the air conditioned room, they add 40 HP.
Jamb then in an insulated engine compartment and bake everything at 300 degrees for maybe 30HP, while cooking the intake air. Wonder what that takes away?
So maybe 20 HP net gain after sucking hot air, while either adding cost or weight or?
The gain versus the toaster oven effect.
Jamb then in an insulated engine compartment and bake everything at 300 degrees for maybe 30HP, while cooking the intake air. Wonder what that takes away?
So maybe 20 HP net gain after sucking hot air, while either adding cost or weight or?
The gain versus the toaster oven effect.
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Le Mans Master
Joined: Dec 2006
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I can speak to side pipe headers. I got mine ceramic coated first, used stage 8 locking header bolts to keep bolts from backing out and never looked back.
no special plug wires routing or socks on them, no special manifold gaskets, NGK plugs, not shorties. I’ve had zero issues with them.
exhaust that is routed out the side making working on anything under the car far more accessible. Also eliminating a source of floor heat. I can access all the plugs easily from above.
for me, headers has made things much easier, not harder.
no special plug wires routing or socks on them, no special manifold gaskets, NGK plugs, not shorties. I’ve had zero issues with them.
exhaust that is routed out the side making working on anything under the car far more accessible. Also eliminating a source of floor heat. I can access all the plugs easily from above.
for me, headers has made things much easier, not harder.
If you want a race car look, you have to do some race car stuff, (Except red boxes).
Racer
Joined: Nov 2019
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From: Canadian living in southern France
Horsepower is fine, but where I live, (twisty, hilly roads), I want torque, especially at lower RPM's.
I'll probably rebuild the engine in December, and will build it for torque, probably keeping the rams horns. I think, for torque, below 3,500 RPM, there would be almost no gain with headers.
I'll probably rebuild the engine in December, and will build it for torque, probably keeping the rams horns. I think, for torque, below 3,500 RPM, there would be almost no gain with headers.
Race Director
Joined: Nov 2006
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And that is why I keep asking the question, how much power and where. 20 HP at 6,000 RPM means little to me, but 50 Foot pounds tourqe at 2,000 RPM would mean bucket loads.
so, has anyone really dyno'd one engine, no changes but exhaust, stock 2inch manifolds, 2 and a half inch manifolds and short and long tube headers. Peek HP at 6,000 might be of interest to a drag racer. But on a short track or the street, tourqe at lower RPM 's is King.
if I'm to give up all my stock ign shielding and head shields. I would like to think there's a good enough reason.
high RPM power from my over 40 year old car means nothing to me.
so, has anyone really dyno'd one engine, no changes but exhaust, stock 2inch manifolds, 2 and a half inch manifolds and short and long tube headers. Peek HP at 6,000 might be of interest to a drag racer. But on a short track or the street, tourqe at lower RPM 's is King.
if I'm to give up all my stock ign shielding and head shields. I would like to think there's a good enough reason.
high RPM power from my over 40 year old car means nothing to me.
Burning Brakes
Joined: Jun 2010
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From: Bellmore NY
A few years back forum member Zwede had posted several dyno runs on his relatively stock LS5. A set of long tube headers made a HUGE gain vs stock manifolds. I want to say around 50 hp. Thats a gain that would be impossible to avoid noticing.
Melting Slicks
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I don't have a dyno run for when I had ram horn manifolds with dual exhaust on my ZZ4, but that engine definitely didn't like old school manifolds at anything above idle. It ran horrible; just wasn't a good combination of exhaust manifold design, exhaust port design, and cam profile. I never could get it tuned so it would run correctly throughout the RPM band. I'm not talking peak HP number, but rather A/F mixture and just good all around running behavior.
When I installed ceramic coated headers the engine responded really well to the exhaust change. I went with the smallest full length header since I wasn't going to be at full throttle all the time, and made sure they accommodated the factory clutch linkage. I had no problems at all installing them, and they've been on the car now for 20 years with no problems. To cure any additional temp in the engine bay that the ceramic didn't prevent, I fabricated a cowl induction system so the engine would be drawing in nice cool outside air.
When I installed ceramic coated headers the engine responded really well to the exhaust change. I went with the smallest full length header since I wasn't going to be at full throttle all the time, and made sure they accommodated the factory clutch linkage. I had no problems at all installing them, and they've been on the car now for 20 years with no problems. To cure any additional temp in the engine bay that the ceramic didn't prevent, I fabricated a cowl induction system so the engine would be drawing in nice cool outside air.
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When you ask where, it depends on the engine build...are we talking stock heads , cam and intake? Then ya, maybe 20hp at the top end, if you start upgrading with an intake , heads with a good cam then you are able to flow more easily into the engine, but if you are plugging the exhaust again you will see it more at the middle and top. If you unplug it with headers you get improved breathing and you get gains at the bottom end...engine masters shows this at times. They did a couple of manifold to header comparisons then later take the same motor and throw a bigger cam in it and it all goes u . BUT THEY EXPLAIN it's all done at wide open throttle so you obviously aren't going to be WOWed with the power your cranking out at idle or cruising though down town...until you see that tuner import at the next light.....blue WRX looking to show of for his friends... BAM Johnny smokes him off the light and the guy gave up about 20 yards down the road...
Last edited by Rescue Rogers; Jul 26, 2020 at 01:25 PM.
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And that is why I keep asking the question, how much power and where. 20 HP at 6,000 RPM means little to me, but 50 Foot pounds tourqe at 2,000 RPM would mean bucket loads.
so, has anyone really dyno'd one engine, no changes but exhaust, stock 2inch manifolds, 2 and a half inch manifolds and short and long tube headers. Peek HP at 6,000 might be of interest to a drag racer. But on a short track or the street, tourqe at lower RPM 's is King.
if I'm to give up all my stock ign shielding and head shields. I would like to think there's a good enough reason.
high RPM power from my over 40 year old car means nothing to me.
so, has anyone really dyno'd one engine, no changes but exhaust, stock 2inch manifolds, 2 and a half inch manifolds and short and long tube headers. Peek HP at 6,000 might be of interest to a drag racer. But on a short track or the street, tourqe at lower RPM 's is King.
if I'm to give up all my stock ign shielding and head shields. I would like to think there's a good enough reason.
high RPM power from my over 40 year old car means nothing to me.
If all you want is a stock engine to putter around in, then of course you wouldn't (and shouldn't) consider headers. But if you're building a 400-500 HP engine, why would you spend all of that money just to choke it with manifolds? Might as well just build the lower HP engine to start with.
Is my vette stock?? HAHA
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With my cam and the headers I get similar questions and surprised looks when I say its just a 327....Then they laugh and say " just a 327" some go on to talk about teenage memories of 327's and how they have become a legend of the past...
Melting Slicks
Joined: Dec 1999
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From: Mid West
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I've had the same comment due to my fabricated valve covers. (Pic was taken prior to my cowl induction setup).
Racer
Joined: Jan 2017
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From: San Francisco Bay Area
I went with Hedman ceramic headers, used a marine spacer so my plugs fit better, added the woven plug heat protection socks, only had to dent the headers around the idler arm and steering box. My perceived cabin heat increase is negligible. On a 2 hour drive I wear sandals and my feet are comfy. I insulated my fuel lines with heat reflective socks and already had a fuel cooler and a cold air horsepower increase is well worth it to me as the rams horns were pretty much a plug for the way I had my motor setup in the past, with the new cam it’s insane!!
Thanks
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THey are made by Hardine marine, theres other companies that make header flanges for custom pipes that can be used but these are 1/2 inch. I read that were originally used on marine engines for alignment of pipe tube issues. They can be used to solve all sorts of issues from alignment of tubes to valve cover clearance to spark plug clearances. THey are bigger inside diameter but I used square port aluminum gaskets on the motor side and oval on the header side. I used Mr gasket, I bought Taylor cable but they have no seal at the bolts. I measured the ports to figure out which Mr Gaskets I needed
https://www.summitracing.com/search/...ial%3Aaluminum
Sealed really well. I think I will eventually have them aluminum welded up to make them more of a square port to oval port adapter so the flow is better...but it works really well now. I talked to an engineer at headman and head said as long as the lip at t he corner was under a 1/16th it wouldnt be a problem..I forget the exact tolerance but it was right there..
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
https://www.summitracing.com/search/...ial%3Aaluminum
Sealed really well. I think I will eventually have them aluminum welded up to make them more of a square port to oval port adapter so the flow is better...but it works really well now. I talked to an engineer at headman and head said as long as the lip at t he corner was under a 1/16th it wouldnt be a problem..I forget the exact tolerance but it was right there..
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
Last edited by Rescue Rogers; Jul 26, 2020 at 08:55 PM.
Thread Starter
Le Mans Master
Joined: Dec 2006
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THey are made by Hardine marine, theres other companies that make header flanges for custom pipes that can be used but these are 1/2 inch. I read that were originally used on marine engines for alignment of pipe tube issues. They can be used to solve all sorts of issues from alignment of tubes to valve cover clearance to spark plug clearances.
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
I had a Hardin Marine shop next to mine for a bit way back when.
Thread Starter
Le Mans Master
Joined: Dec 2006
Posts: 8,837
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Racer
Joined: Jan 2017
Posts: 496
Likes: 153
From: San Francisco Bay Area
THey are made by Hardine marine, theres other companies that make header flanges for custom pipes that can be used but these are 1/2 inch. I read that were originally used on marine engines for alignment of pipe tube issues. They can be used to solve all sorts of issues from alignment of tubes to valve cover clearance to spark plug clearances. THey are bigger inside diameter but I used square port aluminum gaskets on the motor side and oval on the header side. I used Mr gasket, I bought Taylor cable but they have no seal at the bolts. I measured the ports to figure out which Mr Gaskets I needed
https://www.summitracing.com/search/...ial%3Aaluminum
Sealed really well. I think I will eventually have them aluminum welded up to make them more of a square port to oval port adapter so the flow is better...but it works really well now. I talked to an engineer at headman and head said as long as the lip at t he corner was under a 1/16th it wouldnt be a problem..I forget the exact tolerance but it was right there..
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
https://www.summitracing.com/search/...ial%3Aaluminum
Sealed really well. I think I will eventually have them aluminum welded up to make them more of a square port to oval port adapter so the flow is better...but it works really well now. I talked to an engineer at headman and head said as long as the lip at t he corner was under a 1/16th it wouldnt be a problem..I forget the exact tolerance but it was right there..
https://www.cpperformance.com/p-1281...ock-chevy.aspx
https://www.hardin-marine.com/p-1281...ock-chevy.aspx
Burning Brakes
Joined: Jun 2020
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Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,209
Likes: 9,348
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
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I used socket head screws because of the length required and they were drilled for safety wire so they wont loosen up