Header wrap/insulation

[JeepsAndGuns]

Anyone ever use any? I am getting ready to replace the factory steel tube exhaust manifold/header on my wrangler with a stainless steel one. The factory ones are real bad about cracking. I rewelded mine right after I bought the Jeep back in like 2001, its held fine untill lately. I have noticed a hairline crack starting again. So its time for a replacement.
Since the 4.0 has the exhaust and intake on the same side, I was thinking about wrapping the header before I put it on to help cut down on the heat getting thrown off it and getting soaked into the intake. I have heard a lot of people talking about how the wrap rusts out headers, but since this one is stainless, I wont have that problem.

So anyone used header wrap before? Any tips, tricks, or brands/styles to look for?

[EagleMark]

Buy a coated header! Keeps heat in exhaust and not under hood. Does not hold water and dirt to rot header like wrap. Looks good forever... Headman Elite if they make one for your car.

[gregs78cam]

You could try it. I don't know if it's possible but could you make a heat shield for the exhaust. Stainless will keep more of the heat in the tube than mild steel, but will still get hot.

[1project2many]

I always advise to skip it for street vehicles. When I was racing we used wrap on the racecar headers. Even those rusted fairly quickly considering they weren't run in bad weather.

If you want to keep the intake cool, coat the intake with ceramic thermal barrier coating. I did that on my Sunbird and what a difference... you can feel it with your hands. Hot engine, cool to warm intake. Look at tech-line coatings for relatively inexpensive coating you can apply yourself. I just bought another bottle to do a set of pistons.

[JeepsAndGuns]

I have already bought the new hader, should be here today or tomorrow. Plus I couldnt really swing the price of a coated header. Seems like every header I saw that was coated, was just stupid crazy priced over a non coated one.
I will check out that coating for the intake.

[FSJ Guy]

If you can get coating for the intake, why not coating for the header? Maybe there's a brush or spray on coating for headers? <shrug>

[RobertISaar]

If you can get coating for the intake, why not coating for the header? Maybe there's a brush or spray on coating for headers? <shrug>

i had a can of VHT aerosol ceramic.... expensive($8/can) and it really didn't do much at all, other than eventually just flaking off. it even allowed rust underneath it on a turbo housing that has yet to be used.

i'd be interested in seeing what this stuff would do internally as well.... like runner ports and stuff. might keep carbon and oil off of the walls from the PCV and EGR systems?

[1project2many]

Seems like every header I saw that was coated, was just stupid crazy priced over a non coated one.
This product can be applied to a header as well. If done right there's a fair amount of time involved in coating a header. Trying to get into the collector where the tubes are welded together can be a biatch.


i had a can of VHT aerosol ceramic.... expensive($8/can)

This is better quality than VHT. It also costs $32 for an 8 ounce bottle. Aerosol not included.

it really didn't do much at all, other than eventually just flaking off. it even allowed rust underneath it on a turbo housing that has yet to be used.

The key to using this is proper prep work. Complete blasting or acid etching, thorough degreasing, proper application with spray gun. Like paint, poor prep = poor results.


i'd be interested in seeing what this stuff would do internally as well.... like runner ports and stuff. might keep carbon and oil off of the walls from the PCV and EGR systems?
Won't keep wither component off the walls of chambers and ports, but it does take longer for carbon to accumulate and it was easier to remove. Oil is extremely hard to control once it's in a vapor. I've seen an engine with too much TBC applied internally. The oil was always dirty because it never got warm enough.

Look for techline coatings. There used to be a good article on thermal barrier coatings.

[JeepsAndGuns]

I checked out that techline stuff. Seems interesting, a little pricey, but I could swing it if its as good as they say.
Have you personally used it?

[1project2many]

I've been using Techline since '98. First application for the thermal barrier was combustion chambers and pistons in a 350 w/ LT4 HOT cam, Vortec heads and 10.5:1 pistons. Ran 87 octane in it for years. I decided to switch to 2.02 / 1.60 valves and the machine shop couldn't blast the old coating out of the heads. I needed brand new black beauty sand at 150 psi with the nozzle 1" or less from the head to remove it.

[RobertISaar]

that's..... huh.

sometimes i wonder if my 9.6:1 compression could benefit from something higher than 87 octane.... i guess i could actually benefit from more compression. :D

i imagine a little bit of that stuff goes a long way?

[1project2many]

There was a learning curve with the first bottle. I think the website says 1 bottle can do 24 average pistons but I didn't do that well. I started with a Harbor Freight $19 airbrush and some adapters to use it on shop air. Now I use a cheapie paint touch up gun from Advance Auto and try to keep overspray down.

Cleanup and prep consume most of your time during this process. I've switched from sandblasting to acid etching with very good results. You should see what a stainless valve does in hydroflouric acid! (Do not take hydroflouric acid lightly!) But overall I feel the coatings are worthwhile enough to continue using them.

[JeepsAndGuns]

I coated a rifle a few years ago with duracoat and still have a airbrush left over from that, I used a adapter to run it off my air compressor. Do you have to thin this stuff to spray it, or just pour it out of the can into the sprayer?
Just how well does it insulate the heat? As much as the header wrap? What about coating both my intake and the new header? I assume it sticks to stainless steel just fine?

[gregs78cam]

After checking out some of the available products, I may have to use a couple when I do the Camaro's powertrain transplant. Those coatings sound pretty sweet.

[1project2many]

I would say TBC insulates as well as a single pass with header wrap. Wrap can be applied in multiple layers though so in the end I think you could make it insulate better. The thermal barrier coating in the small bottle seemed to be more effective for heat than the exhaust coating.

The retail coatings are water based. You can add distilled water if they dry out but you're not supposed to thin before spraying. I had no problems with adhesion to stainless but again I etched it with hydroflouric acid. Stainless in HFl foams like mixing baking soda and battery acid. If you use a good blaster with sharp sand then degrease properly afterward you should have no issues with stainless.

They've been good about answering questions for me. I've called and gotten someone to talk with fairly quickly. Now there's a forum which has professional coaters as well as hobbyists and has some interesting reading.

[JeepsAndGuns]

Bringing this back up. The header I bought ended up leaking on me. I thought it cracked. It was a cheap header. So I broke down and bought a high end header. I coated it in techline coatings, just like the first one. Well it turned out, there was a problem with the header and the flange was made wrong causing a leak. I looked at the old cheap header and found it had just had a weld that didnt stick in one spot and blew out. I welded it up and put it back on. I sent the expensive one to get warrentied. I have the replacement and it seems to be right. So now I want to coat it and put it on. But now I call to order some techline coatings and they no longer sell to the public, only business "that can apply it for me"
So far google hasnt found me a source for any yet.
So any other suggestions for other brands of coatings?