Should I wrap my exhaust manifold? - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Should I wrap my exhaust manifold?

Reply

 
 
 
Old 09-11-2017, 08:45 PM
  #1  
89dd
CF Senior Member
Support Corvetteforum!
Thread Starter
 
89dd's Avatar
 
Member Since: Jul 2012
Location: NYC
Posts: 334
Thanked 11 Times in 3 Posts
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.
89dd is offline  
Reply With Quote
Old 09-11-2017, 10:14 PM
  #2  
ex-x-fire
CF Senior Member
 
ex-x-fire's Avatar
 
Member Since: Dec 2009
Posts: 1,484
Thanked 53 Times in 49 Posts
Default

Have them coated.
ex-x-fire is offline  
Reply With Quote
Old 09-11-2017, 11:35 PM
  #3  
aklim
CF Senior Member
 
aklim's Avatar
 
Member Since: Jul 2004
Location: Hartford WI
Posts: 13,977
Thanked 655 Times in 643 Posts
Default

If you have no other mods, just replace it.
aklim is offline  
Reply With Quote
Old 09-11-2017, 11:52 PM
  #4  
gerardvg
CF Senior Member
 
gerardvg's Avatar
 
Member Since: Aug 2009
Location: Melbourne, Australia Victoria
Posts: 3,074
Thanked 95 Times in 95 Posts
Default

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.
gerardvg is offline  
Reply With Quote
Old 09-12-2017, 12:00 AM
  #5  
aklim
CF Senior Member
 
aklim's Avatar
 
Member Since: Jul 2004
Location: Hartford WI
Posts: 13,977
Thanked 655 Times in 643 Posts
Default

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.
Sure about the melting part? Or is it rust because it retains moisture?
aklim is offline  
Reply With Quote
Old 09-12-2017, 12:16 AM
  #6  
gerardvg
CF Senior Member
 
gerardvg's Avatar
 
Member Since: Aug 2009
Location: Melbourne, Australia Victoria
Posts: 3,074
Thanked 95 Times in 95 Posts
Default

Originally Posted by aklim View Post
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.
gerardvg is offline  
Reply With Quote
Old 09-12-2017, 12:19 AM
  #7  
aklim
CF Senior Member
 
aklim's Avatar
 
Member Since: Jul 2004
Location: Hartford WI
Posts: 13,977
Thanked 655 Times in 643 Posts
Default

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".
aklim is offline  
Reply With Quote
Old 09-12-2017, 08:11 AM
  #8  
89dd
CF Senior Member
Support Corvetteforum!
Thread Starter
 
89dd's Avatar
 
Member Since: Jul 2012
Location: NYC
Posts: 334
Thanked 11 Times in 3 Posts
Default

Not using headers, replacing stock manifold
89dd is offline  
Reply With Quote
Old 09-12-2017, 08:32 AM
  #9  
aklim
CF Senior Member
 
aklim's Avatar
 
Member Since: Jul 2004
Location: Hartford WI
Posts: 13,977
Thanked 655 Times in 643 Posts
Default

Originally Posted by 89dd View Post
Not using headers, replacing stock manifold
Still would NOT
aklim is offline  
Reply With Quote
Old 09-12-2017, 10:05 AM
  #10  
vette196
CF Senior Member
 
vette196's Avatar
 
Member Since: Feb 2015
Location: Park Ridge New Jersey
Posts: 645
Thanked 41 Times in 38 Posts
Default

I would get LT1 exhaust manifolds for a 89, if you're not going the header route
vette196 is offline  
Reply With Quote
Old 09-12-2017, 10:37 AM
  #11  
whalepirot
CF Senior Member
 
whalepirot's Avatar
 
Member Since: Jan 2008
Location: MV Kali
Posts: 2,024
Thanked 88 Times in 81 Posts
Default

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.
whalepirot is online now  
Reply With Quote
Old 09-12-2017, 05:06 PM
  #12  
ctmccloskey
CF Senior Member
Support Corvetteforum!
 
Member Since: May 2001
Location: Fairfax Virginia
Posts: 383
Thanked 83 Times in 77 Posts
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....
ctmccloskey is online now  
Reply With Quote
Old 09-13-2017, 02:46 PM
  #13  
hcbph
CF Senior Member
 
hcbph's Avatar
 
Member Since: Aug 2013
Location: Minneapolis Mn
Posts: 3,312
Thanked 323 Times in 309 Posts
Default

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.
hcbph is offline  
Reply With Quote
Old 09-13-2017, 02:55 PM
  #14  
aklim
CF Senior Member
 
aklim's Avatar
 
Member Since: Jul 2004
Location: Hartford WI
Posts: 13,977
Thanked 655 Times in 643 Posts
Default

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.
aklim is offline  
Reply With Quote
Old 09-14-2017, 03:37 PM
  #15  
STH
CF Senior Member
 
Member Since: Mar 1999
Location: Udhailiyah
Posts: 207
Thanked 0 Times in 0 Posts
Default

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.
STH is offline  
Reply With Quote
Old 10-01-2017, 03:04 AM
  #16  
killlerkc
CF Member
 
killlerkc's Avatar
 
Member Since: Sep 2011
Location: Temecula CA
Posts: 89
Thanked 0 Times in 0 Posts
Default

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....
killlerkc is offline  
Reply With Quote
Old 10-01-2017, 03:46 AM
  #17  
gerardvg
CF Senior Member
 
gerardvg's Avatar
 
Member Since: Aug 2009
Location: Melbourne, Australia Victoria
Posts: 3,074
Thanked 95 Times in 95 Posts
Default

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 03:47 AM.
gerardvg is offline  
Reply With Quote
Old 10-01-2017, 09:16 AM
  #18  
Dt86
CF Senior Member
 
Dt86's Avatar
 
Member Since: Jan 2014
Location: Poughkeepsie New York
Posts: 3,524
Thanked 213 Times in 200 Posts
Default

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.
Dt86 is offline  
Reply With Quote
 
 
 


Thread Tools
Search this Thread
Quick Reply: Should I wrap my exhaust manifold?


Sponsored Ads
Vendor Directory

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: