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Should I wrap my exhaust manifold?

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Old 09-11-2017, 09:45 PM   #1
89dd
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Default Should I wrap my exhaust manifold?

Drivers side manifold cracked and needs replacing. Ordered one from eBay and it's on it's way. I'm cutting off and plugging the emission tubes and refinishing to clean up engine bay.
Should I put the stock heat shields back on or wrap them,or both.
I know now is the time to switch to long tubes but I got to keep wifey happy too. She thinks it's already too loud with the Borla cat back.
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Old 09-11-2017, 11:14 PM   #2
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Have them coated.
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Old 09-12-2017, 12:35 AM   #3
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If you have no other mods, just replace it.
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Old 09-12-2017, 12:52 AM   #4
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Originally Posted by 89dd View Post
Drivers side manifold cracked and needs replacing. Ordered one from eBay and it's on it's way. I'm cutting off and plugging the emission tubes and refinishing to clean up engine bay.
Should I put the stock heat shields back on or wrap them,or both.
I know now is the time to switch to long tubes but I got to keep wifey happy too. She thinks it's already too loud with the Borla cat back.
Hi
Coated inside and out is fine, don't wrap them the headers will melt with the heat. Happened to my previous headers new to junk within a year got so thin I could poke holes in the headers.
Had my HTC coated headman headers for 3 years still good.
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Old 09-12-2017, 01:00 AM   #5
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Hi
Coated inside and out is fine, don't wrap them the headers will melt with the heat. Happened to my previous headers new to junk within a year got so thin I could poke holes in the headers.
Had my HTC coated headman headers for 3 years still good.
Sure about the melting part? Or is it rust because it retains moisture?
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Old 09-12-2017, 01:16 AM   #6
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Sure about the melting part? Or is it rust because it retains moisture?
Hi
Yeah they slowly go thin from the heat, you can see how hot headers get when running in a cam for instance 20 min's at 2,000 rpm stationary. plain painted headers glow red / orange hot in the engine bay, when the headers are wrapped they get so hot .... unwrapped when driving the airflow in the engine bay keeps the headers cool.

It was lesson learned for me, I make sure my headers are HTC coated inside and out or just plain painted.

Am sharing my experience so others don't make the same mistake.
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Old 09-12-2017, 01:19 AM   #7
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Originally Posted by gerardvg View Post
Hi
Yeah they slowly go thin from the heat, you can see how hot headers get when running in a cam for instance 20 min's at 2,000 rpm stationary. plain painted headers glow red / orange hot in the engine bay, when the headers are wrapped they get so hot .... unwrapped when driving the airflow in the engine bay keeps the headers cool.

It was lesson learned for me, I make sure my headers are HTC coated inside and out or just plain painted.

Am sharing my experience so others don't make the same mistake.
It took a couple years but my buddy's F-body had wrapped headers. Can't remember the brand. One day he had me come over to help re-wrap them because they were getting nasty from oil spills. We took the wraps off and saw rust spots and "Holey Headers, Batman".
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Old 09-12-2017, 09:11 AM   #8
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Not using headers, replacing stock manifold
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Old 09-12-2017, 09:32 AM   #9
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Not using headers, replacing stock manifold
Still would NOT
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Old 09-12-2017, 11:05 AM   #10
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I would get LT1 exhaust manifolds for a 89, if you're not going the header route
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Old 09-12-2017, 11:37 AM   #11
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I ran wrapped long tubes for many years and when removed were just fine. This is a dry clime, howeve, and I used the special header wrap paint on them. Given the effort and expense, hot coating of those thin tubes is mandatory for me, now.

That said, I see little value in treating stock exhaust and long tubes will not make it much louder, but recommend reinstalling the hear shields on the stock setup.
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Old 09-12-2017, 06:06 PM   #12
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Default Coated headers or manifolds.

I have long-tube Hedman Headers that came coated with the silver color hi-temp coating. They started developing big orange spots on them so I called Hedman and they sent me a second set, freshly coated. Those did not fit my car so back they went. The third set are on the car now and they look like hell, again.

I have spoke with Hedman about this issue. It seems that if you have a cement pad in your garage like I do, it can have an effect on your headers staying nice and pretty. They told me that "something leaches out of exposed concrete that damages the coatings". They suggested I either paint the concrete floor or put down a piece of cardboard on the floor under my engine.

Has anybody else ever heard anything like this?

I finally got Hedman to tell me who did their coatings and then I found out that their coatings had two levels. The standard level works okay if you protect it. I learned that the higher grade coatings have higher temperature protection which is critical in my engine with it's 12.25-1 Compression ratio due to the higher cylinder temperatures.

If I were replacing a original exhaust manifold I would seriously consider a hi-Temp coating. I would also do the pipes that attach to the manifold. The temperature reductions are very real, I have never tested the power differences they "claim". It might be a pain in the butt to remove both manifolds and pipes in your car but the results look good and help control the excessive heat in that part of the car!

Good Luck but please don't wrap those manifolds....
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Old 09-13-2017, 03:46 PM   #13
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Quote:
Originally Posted by ctmccloskey View Post
I have spoke with Hedman about this issue. It seems that if you have a cement pad in your garage like I do, it can have an effect on your headers staying nice and pretty. They told me that "something leaches out of exposed concrete that damages the coatings". They suggested I either paint the concrete floor or put down a piece of cardboard on the floor under my engine.

Has anybody else ever heard anything like this?
Anything is 'possible', whether little green men or exposing gas from concrete. Put a battery on concrete and over time it will discharge. Then again does it discharge due to contact with the cement or is it doing it naturally?

Moisture can leech through concrete and water can come out of it when it's green. I find it a little hard to swallow but then again I don't have headers on my vehicles.
You would have thought if this was an issue others would have posted something on it, but then again I don't know. Do other manufacturers claim this is an issue?

This is one for the MYTH BUSTERS IMO.
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Old 09-13-2017, 03:55 PM   #14
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Quote:
Originally Posted by hcbph View Post
Anything is 'possible', whether little green men or exposing gas from concrete. Put a battery on concrete and over time it will discharge. Then again does it discharge due to contact with the cement or is it doing it naturally?

Moisture can leech through concrete and water can come out of it when it's green. I find it a little hard to swallow but then again I don't have headers on my vehicles.
You would have thought if this was an issue others would have posted something on it, but then again I don't know. Do other manufacturers claim this is an issue?

This is one for the MYTH BUSTERS IMO.
My driveway is concrete. The battery draining on concrete probably was from old times which are not good anymore today.
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Old 09-14-2017, 04:37 PM   #15
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Quote:
Originally Posted by gerardvg View Post
Hi
Coated inside and out is fine, don't wrap them the headers will melt with the heat. Happened to my previous headers new to junk within a year got so thin I could poke holes in the headers.
Had my HTC coated headman headers for 3 years still good.
I had wrapped a set of headers once on my 85 Blazer, they melted in several locations, and became unweldable after two years. As you said holes would blow through the metal. Replaced them with a set of coated headers and never again had a problem.
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Old 10-01-2017, 04:04 AM   #16
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Quote:
Originally Posted by vette196 View Post
I would get LT1 exhaust manifolds for a 89, if you're not going the header route
How does that work worth L98 going to a LT1 exhaust manifold. Let me know. Thx....
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Old 10-01-2017, 04:46 AM   #17
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Quote:
Originally Posted by ctmccloskey View Post
I have long-tube Hedman Headers that came coated with the silver color hi-temp coating. They started developing big orange spots on them so I called Hedman and they sent me a second set, freshly coated. Those did not fit my car so back they went. The third set are on the car now and they look like hell, again.

I have spoke with Hedman about this issue. It seems that if you have a cement pad in your garage like I do, it can have an effect on your headers staying nice and pretty. They told me that "something leaches out of exposed concrete that damages the coatings". They suggested I either paint the concrete floor or put down a piece of cardboard on the floor under my engine.

Has anybody else ever heard anything like this?

I finally got Hedman to tell me who did their coatings and then I found out that their coatings had two levels. The standard level works okay if you protect it. I learned that the higher grade coatings have higher temperature protection which is critical in my engine with it's 12.25-1 Compression ratio due to the higher cylinder temperatures.

If I were replacing a original exhaust manifold I would seriously consider a hi-Temp coating. I would also do the pipes that attach to the manifold. The temperature reductions are very real, I have never tested the power differences they "claim". It might be a pain in the butt to remove both manifolds and pipes in your car but the results look good and help control the excessive heat in that part of the car!

Good Luck but please don't wrap those manifolds....
Hi
My headman HTC coated headers still look great after 3 or so years, some slight discoloring from heat at the first few inches but great from there to under the car.
My garage has plain concrete / cement, no special coatings.

Last edited by gerardvg; 10-01-2017 at 04:47 AM.
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Old 10-01-2017, 10:16 AM   #18
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Quote:
Originally Posted by 89dd View Post
Drivers side manifold cracked and needs replacing. Ordered one from eBay and it's on it's way. I'm cutting off and plugging the emission tubes and refinishing to clean up engine bay.
Should I put the stock heat shields back on or wrap them,or both.
I know now is the time to switch to long tubes but I got to keep wifey happy too. She thinks it's already too loud with the Borla cat back.
Like everyone says, don't wrap it. I would put the heat shield on. You can hit it with some 0000 steel wool to make it look nice. I think it dresses up the engine bay.
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