Exhaust header paint

Ceramic coating

 

There's nothing I've ever seen in an aerosol can that will stay on very long.

Jet-Hot is the original but they're expensive. Some other places are offering a similar product.

Eastwood does sell a powder coating product that supposedly works on headers.

 

I would think that ceramic coating a header that was not originally ceramic coated would hold heat causing increase temps both upstream (head and valves) as well as downstream.

Is this correct?

 

www.jet-hot.com

www.performancecoatings.com

Both are VERY good companies and prices are not that bad.

 

That's what I've been thinking, but the folks at Jet-Hot 'might' be smart enough to coat the INSIDE of the tubes, insulating the steel from the higher temps and preventing premature failure. NOT doing so probably would cause the OEM steel to fail faster than if the tubes were never coated at all and allow some of the heat to radiate out....its just an educated guess, though.

 

http://www.hpcoatings.com/am/products/products_heat.aspx

I used HPC's coating on my Honda when I built it and I am still convinced that it was the best addition for making consistent power. It also went through a LOT of abuse and still looked good with a damp rag wipedown.

Jet-Hot has a lot of experience with Ferrari headers and should bring a good level of comfort to you. The link above does a good enough job of explaining why it is a good idea.

 

Jet Hot does coat both the inside and outside of headers. I had my 308 headers done last winter, as did my friend Paul. I have also done Jet Hot on exhaust manifolds for old Jaguars with great success. My 308 headers were done in silver, and look great. I have driven the car pretty well since putting them back on, and the Jet Hot coating is holding up perfectly. Still looks brand new. NAYYY, just a happy customer who would highly recommend them. And personally, I don't think the price of the Jet Hot is very high, considering what they do and what the end product looks like.

 

www.por15.com

I've been very happy with their product. Had good results over time, easy to touch up (rarely needed). Inexpensive and easy to do in your own home or shop.

 

I've always wondered how or if they "prepare the surface" inside a used header. Lots of pretty inacccessible places that would likely be covered with rust and exhaust byproducts.

If you've ever media blasted a rusty part you would know how hard it is to clean the areas you can actually see let alone the inside.

As to coating the inside, I think we take that on faith for the same reason. Has anyone ever cut one open to look at the coating?

 

I was just about ready to box up a set of headers a year and a half ago, when somewhere here on Fchat the process was called into question. It has not been answered in any way that I have seen yet to date. The only evidence ever cited is always the information Jet Hot and other coating companies are selling us, never any outside testing. Heat doesnt just disappear, it has to go somewhere. Is it staying inside the engine, or is it really being forced out into the muffler? Some have questioned if its not trapped in the steel header material, and embrittling it to the point where it suddenly fails. I dont know. I know our son had a set of headers on his Mazda coated, and then the primaries started cracking at the collectors. I have a set of headers off the last 308 that had a broken primary, but they were the factory wrapped headers so maybe retained to much heat?? Old??

I didnt know what to do, so I cleaned them up and sprayed them down with several coats of VHT 1500 F degree flat black. A year and a half later they are still all black. In reading the Jet Hot information, the standard coatings arent guaranteed to withstand temps above 1200 F. The metalic black coating is supposedly able to withstand 1500 F, but at nearly $500 its as expensive as a good used set of headers. Pretty hard to beat a $6 can of VHT 1500 F spray paint IMHO. Besides, I think once the headers are coated, there is no going back. I figure if the original headers lasted 30 years, a little paint wont hurt them. But I wont be sending any headers to be coated until the questions are resolved.

 

I have Jet-hot the headers on my Ferrari and on my Porsche race car I can confirm that is does not raise the operating temp of the motor. I can also confirm that is is far, far more durable than paint. They claim it can reduce operating temps inside the engine compartment which I can not confirm.

The headers and muffler on my ferrari are jet-hot coated. a lot of people mistake it for chrome; right there it is worth the $90.00. The headers on my porsche were fabbed by a company in CA and they sent to a local coater....dull gray...not exciting and does not appear to be nearly as thick and or tough as jet-hot.

When I replaced the headers on My ferrari I jet-hotted the old set before I sold them. Here are before and after photos.
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I used Performance Coatings. They are very resonable. I couldn't use the chrome like finish as it's a fresh rebuild and the high temp of break in will burn off the finish. I used the steal grey which they say is much more durable.
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I track my car occasionally and that heat has not effected the chrome like finish. It is ceramic. It has been 18 months on the car and yes, right at the head it is getting a little dull, but absolutely no blueing.

And since I put it on a set I was selling I did give it the hammer test. I can verify that Jet-hot is tough enough to stand up to hammer blows.

 

Anything that was ever wrapped is going to last 1/4 of the time if that. Moisture condenses under the wrap and rots the metal. Quick gains and the same principle as coating, but fast failures.

Anyone please step in to help me on this one. There's something I think I'm missing:

The reason for coating is to keep the hot gas hot and flowing faster towards the cooler end of the pipe. As the gasses cool they actually will create a "pull" and help the flow. This is why you only see headers and downpipes coated. Never the exhaust pipes or mufflers.

They heat is still moving out of the engine and isn't sitting anywhere. You are just maximizing the flow of gasses.

anyone for something more technical?

As for painting, sure you can cover the outside and have it stay black, but there's no way a human can consistently coat the metal to maximum benefit. This process is simply anodizing/powdercoating with high temperature ceramic material. The inside is the key to the performance.

 

I wonder if this is why Jet-Hot won't let you see how they coat the inside. They say it is propriotery. and is much smoother than the other coaters I've used.

 

You got it. Keep the heat flowing out so it doesn't soak into the header Ceramic coating the header will NOT cause the metal to get hotter unless the wrong coating is used (there are those that absorb heat). You can coat your piston tops, too, as well as other parts. Ceramic coatings can be used for lubricating surfaces as well.

Nothing wrong with coating a muffler, however, a stainless steel muffler looks good, is durable, and keeps the heat in as well. I have ceramic coated my entire exhaust system on my air-cooled VW engine and it helps to keep under-hood temps from getting out of control on a big engine which a bigger concern than on water-pumpers.

 

Im not sure if your familiar with the early 308, but the US cars had heavy blankets of asbestos (or something that looks like asbestos) wrapped around the headers, then wrapped with aluminum slip covers to hold it all together. Mine are 30 years old, as are most everyone elses, they held up VERY well IMHO. And mine arent rotted, I just had one cracked/broken primary at the collector end. Plenty O metal to re-weld it back together and get another 30 years out of them.

 

That's cool. I just went with what the guys at Performance Coatings said- that putting them on a motor that was going to be broken in would burn the material off. They said it has to heat cycle to fully bake on. Who knows.... I do like that chrome-like finish though.....

 

I'm real weary about using header tape. I've seen people use it on race cars and have seen all kinds of header failures. I only use it on specific problem areas ie:a small section of header near the starter or near an oil line. If I do use it I try to stay as far away from the head as posible. I talked with a header company years ago and they told me the leading cause of header failures was header tape. Seen the headers deform from the heat so bad they had to be trashed. I'm a believer in JetHot or ceramic coating. It seems to hold up better than anything that ever came out of a spray can and a lot of header manufacturers offer it as an option on new headers. I've seen it on enough racecars that someone would have to show me some reason not to use it.

If you like black and don't get the headers wet I used to use black stove polish on one of my motorcycles and had good luck. Nice thing was if they started to dull or rust you could just wipe on some more with a rag and it doesn't flake off like paint.