Instead of header wrap...
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,692
Likes: 29
From: Texas
Instead of header wrap...
how about exhaust jackets.
http://www.thermotec.com/products/11...t-jackets.html
These fit looser and allow for expansion and air between exhaust and material. Wouldn't this overcome some of the negatives of the wrap, that being exhaust cannot expand.
http://www.thermotec.com/products/11...t-jackets.html
These fit looser and allow for expansion and air between exhaust and material. Wouldn't this overcome some of the negatives of the wrap, that being exhaust cannot expand.
Thread Starter
Le Mans Master
Joined: May 1999
Posts: 6,692
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From: Texas
Race Director
Joined: Aug 2004
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From: Duvall, WA
Pro
Joined: Jan 2009
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Not trying to start an argument or anything but that IS the point of header wrap. Heat stays in the pipe and goes out the end iso your engine compartment.
Pro
Joined: May 2003
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From: London England
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Drifting
Joined: Jun 2007
Posts: 1,404
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From: Ansonia/NYC CT
Heat not being able to seep off of your headers will severly reduce the life of said headers. I understand that the point is to reduce under hood temps...but the cost will be the life of your 300+ dollar headers. Rather than wrap the headers, I would wrap whatever you feel can or will be damaged by the heat the headers cause. There is a reason why wrapping headers voids their warrenty.
Drifting
Joined: Jun 2007
Posts: 1,404
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From: Ansonia/NYC CT
I'm not arguing that. Having a cooler engine bay, meaning a motor that has an easier time running cooler, has it's perks as well.
But this comes at the cost of losing 25-30 % life on the headers. In other words, instead of having to replace them in 10 years, for an ordinary, 5,000 miles a year driven car, they will need to be replaced in 6 or 7. And if the car is raced...you're looking at much less. Nascar used to use header wrap, and had to replace headers after every single serious race. Some races ended with the wrap being the only thing left holding the exhaust system together.
Just my .02 cents, but the extra 2-4hp gain this will yield you simply isn't worth the cost. And if it's under hood components being damaged by heat that is the concern, there are many better ways to protect those components, that don't result in ruined headers.
But this comes at the cost of losing 25-30 % life on the headers. In other words, instead of having to replace them in 10 years, for an ordinary, 5,000 miles a year driven car, they will need to be replaced in 6 or 7. And if the car is raced...you're looking at much less. Nascar used to use header wrap, and had to replace headers after every single serious race. Some races ended with the wrap being the only thing left holding the exhaust system together.
Just my .02 cents, but the extra 2-4hp gain this will yield you simply isn't worth the cost. And if it's under hood components being damaged by heat that is the concern, there are many better ways to protect those components, that don't result in ruined headers.
Pro
Joined: May 2003
Posts: 593
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From: London England
I think it depends how you look at it.
The biggest single source of heat under the hood is the headers.
It might mean that you have to replace the headers more often, but the reduction in under hood temperatures increases the service life of so many other components.
Heat kills ignition wires, water hoses, paint finishes, belts, I could go on. So you have to weigh up, do you want to replace something that will corrode and possibly fail anyway after 5-7 years, or replace numerous other under hood items that may last 4 or 5 times longer without the high under hood temperatures.
Also how much heat wrap effects headers is directly proportional to what they're made from. Although they both have similar upper melting points, I've found stainless steel headers are far more resilient under heat wrap than cheap mild steel.
The biggest single source of heat under the hood is the headers.
It might mean that you have to replace the headers more often, but the reduction in under hood temperatures increases the service life of so many other components.
Heat kills ignition wires, water hoses, paint finishes, belts, I could go on. So you have to weigh up, do you want to replace something that will corrode and possibly fail anyway after 5-7 years, or replace numerous other under hood items that may last 4 or 5 times longer without the high under hood temperatures.
Also how much heat wrap effects headers is directly proportional to what they're made from. Although they both have similar upper melting points, I've found stainless steel headers are far more resilient under heat wrap than cheap mild steel.
Drifting
Joined: Jun 2007
Posts: 1,404
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From: Ansonia/NYC CT
I've already burrows two sets of spark plug wires due to header heat. But now I've got it sorted, and everything under the hood is heat proofed. I checked it with an ir gun just to be sure. I'm not totally against header sealing, it's just that I have seen what doing this can do to the things. Specially if those headers are more or less forgotten about, and never checked up on. I DO thing these jackets are a step up, though.
Race Director
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From: Duvall, WA
Le Mans Master
Joined: Jun 2007
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From: Where it's always hot as Hell-South Louisiana.
St. Jude Donor '07-'08-'09-'10-'11-'12-'13
Wrapping hedders does NOT increase the hedder temperature. It will only increase the residence time the heat stays in the hedder metal. Manufacturers are voiding the warranty on those that are wrapped b/c they can, and they will make more money. If you would like discuss metal and heat transfer, I'm game. Disclaimer. I AM a rocket scientist. 
My hedders are wrapped, just ordered the plug boot wraps too.
My hedders are wrapped, just ordered the plug boot wraps too.
Melting Slicks
Joined: Jun 2004
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From: westmoreland N.H.
Drifting
Joined: Jun 2007
Posts: 1,404
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From: Ansonia/NYC CT
Drifting
Joined: Jun 2007
Posts: 1,404
Likes: 1
From: Ansonia/NYC CT
I didn't say that wraps increase temps within the headers...it prevents heat from leaking out. Which, of course, is the point of them.
Wraps act like a sponge. Any chemical at all that gets on them, get absorbed. Anything at all. So, if there is salt in the air where you live, salt will be absorbed into the wrap. Turn on the heat, and what do you have? Accelerated corrosion. Of if you live somewhere where it snows, and they put salt on the road. That salt is still there, on that road, even after the snow has melted. It gets absorbed into the wrap. But hey, don't take MY word for it. You've got google. Check it out for yourself.
Do header wraps work? Yes. Are they the cheapest way to reduce engine bay temps, and keep the motor running cooler, etc? Yes.
But that has a cost. If that cost is worth it to you, then fine. Some guys are also cool with running a 100 shot of nitrous on a stock bottom end to get that hp boost. Is it the cheapest way to get that boost? Sure is.
Wraps act like a sponge. Any chemical at all that gets on them, get absorbed. Anything at all. So, if there is salt in the air where you live, salt will be absorbed into the wrap. Turn on the heat, and what do you have? Accelerated corrosion. Of if you live somewhere where it snows, and they put salt on the road. That salt is still there, on that road, even after the snow has melted. It gets absorbed into the wrap. But hey, don't take MY word for it. You've got google. Check it out for yourself.
Do header wraps work? Yes. Are they the cheapest way to reduce engine bay temps, and keep the motor running cooler, etc? Yes.
But that has a cost. If that cost is worth it to you, then fine. Some guys are also cool with running a 100 shot of nitrous on a stock bottom end to get that hp boost. Is it the cheapest way to get that boost? Sure is.
Le Mans Master
Joined: Jun 2007
Posts: 7,666
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From: Where it's always hot as Hell-South Louisiana.
St. Jude Donor '07-'08-'09-'10-'11-'12-'13
"Do header wraps work? Yes. Are they the cheapest way to reduce engine bay temps, and keep the motor running cooler, etc? Yes."
a wrapped set of hedders= $400, should last 7-9 years depending on use, ambient conditions, storage conditions, etc... so lets take the mean of , say 8 years, or $50/year
a non wrapped set will last 10 - 12 years, or a mean of 11 years at $300 total cost or ~ $28/year....
So, I'm paying $50/year to run wrapped hedders that displace 50-70% more engine heat OUT of the engine compartment, keeping the heads,plug assemblies cooler and allows the engine to breathe cooler air, all for only $20/yr more? Geez, is there another topic we can spend more time on and save more money?
b/t/way- no labor cost around here as I do my own.
also, I recently bought a set of Hedman long tubes, non ceramic coated. Ordered 2 rolls hedder wrap from Jegs- $65 including shipping. Spent less than $400 for the setup.
a wrapped set of hedders= $400, should last 7-9 years depending on use, ambient conditions, storage conditions, etc... so lets take the mean of , say 8 years, or $50/year
a non wrapped set will last 10 - 12 years, or a mean of 11 years at $300 total cost or ~ $28/year....
So, I'm paying $50/year to run wrapped hedders that displace 50-70% more engine heat OUT of the engine compartment, keeping the heads,plug assemblies cooler and allows the engine to breathe cooler air, all for only $20/yr more? Geez, is there another topic we can spend more time on and save more money?
b/t/way- no labor cost around here as I do my own.
also, I recently bought a set of Hedman long tubes, non ceramic coated. Ordered 2 rolls hedder wrap from Jegs- $65 including shipping. Spent less than $400 for the setup.
Last edited by mikejpss; Jun 21, 2011 at 12:18 PM.
Melting Slicks
Joined: Aug 2008
Posts: 2,200
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From: Lehigh county Pennsylvania
WOW!!!, have my Doug Thorley headers led a charmed life...36 years and still going strong. There have been some weld repairs done over the decades from unexpected off-road excursions from time to time...but they're probably 95% original.
Although the #8 pipe has been wrapped for about 2 years to reduce heat to the starter. We'll see if that part degrades any faster than the non-wrapped tubes.
Although the #8 pipe has been wrapped for about 2 years to reduce heat to the starter. We'll see if that part degrades any faster than the non-wrapped tubes.