Porcelainized exhausts....

[CliffBeer]

Anyone in the US have experience with porcelainizing (if that's a word!) their bundle of snakes? I'm guessing this will bring temps down in the engine bay by more than just a couple degrees - and it looks nice too.

Anyone used Jet Hot coating? Recommend a place to have this done?

Thanks in advance.

 

[Bill Bayard]

Cliff,

If you mean ceramic coating, there are quite a few guys that have had this done, myself included. It does make a difference in engine bay temperature. I have no insulation on either the pipes or rear clip, and have never had a paint or fiberglass issue. My car also has ceramic coated coolant pipes (front bay to engine bay), which seems to keep the transfer of heat into the cockpit down nicely.

If you have this done, don't expect the pipes to stay nice and shiny forever, because the internal heat will eventually turn your primaries and collectors to a grayish silver. Also, beware of washing the car with hot pipes. Soapy water leaves spots/stains on the ceramic coating, that are a bitch to get off!

Although I have never used them, I have heard nothing but good about Jet Hot coatings.





Bill

 

[CliffBeer]

Hi Bill, thanks. Yes, ceramic = percelain, same thing. Good information - very helpful. I'm not sure what Jet Hot is - like you, I have heard good things about it however.

Did your car come with the ceramic coating? Or, did you have this done somewhere?

 

[Bill Bayard]

Cliff,

I ordered my pipes that way from GT40 Australia.

There should be a Jet Hot shop within a reasonable distance of you. I live in the middle of nowhere, and there's a shop within 15 minutes of here. Try the Yellow Pages perhaps?

Make sure you get them done inside and out.



Bill

 

[Dave Lindemann]

Cliff -
I installed headers on my Esprit and had them ceramic coated. It works well and looks great. I may be wrong about this but I believe Jet Hot is basically a ceramic coating. I found a local company (MN) that does powder coating and ceramic coating. Ceramic coating is basically powder coating using a different powder and curing at a higher temperature. The material that was applied to my headers also required polishing - which the coater performed. You end up with a high gloss silver coating. I'm sure you should be able to find someone in the Seattle/Tacoma area that could do this for you.
Good luck!
Dave Lindemann

 

If you like the look of ceramic coated headers, then go for it, but they will not lower the surface temperature of the exhaust pipes. I've done testing on a car and my company has done testing on large mining diesel engines with this sort of coating and it has no measureable effect on the temperature of the exhaust component. Still, it's your money, so believe what you want...

 

[CliffBeer]

If you like the look of ceramic coated headers, then go for it, but they will not lower the surface temperature of the exhaust pipes. I've done testing on a car and my company has done testing on large mining diesel engines with this sort of coating and it has no measureable effect on the temperature of the exhaust component. Still, it's your money, so believe what you want...

Hi grrowlgt, interesting how your experience is contrary to the vast majority and long-standing accepted position here. Specifically, the automotive industry, particularly the racing community, has long held that ceramic/porcelain coatings do measurably reduce the surface temp of exhaust systems by increasing the thermal delta at the exhaust tip. In fact, as you may know, there is an entire industry built around this premise. Perhaps you have some further empirical information you can share so that myself, and the rest of us, have some real understanding of why the long standing belief about the effectiveness of such coatings has been in error. Thanks in advance.

 

[Bob I.]

ceramic coating

I just had mine done here in Sacramento Ca. for under 300 USD.(AIC Coatings)
There are many places around that offer the service.The local circle track guys should know where to send you, they seem to be a good resource.

It very well might be true that the actual surface temrerature of a coated vs uncoated exhaust pipe is the same but the benefit of ceramic coating is that it cuts down on the radiant heat by as much as 75%.(Depending the color you choose.)
I was very suspicious of this claim until I had my set done and I will say that before I coated my headers my wires+ looms kept melting and the car would become heat soaked with in 40 min.Now after coating I can keep my bare knuckles as close as 1/2 inch with out singing the hair on my hands and no more melted parts.Now after 40 minutes the intake manifold is radiating more heat than the exhaust is.Bottom line is that it makes a positive noticeable difference.
I would be skeptical about paying extra for the inside of your pipes to be coated.The key to this coating surviving any amount of time under these extreme conditions is proper preparation of the metal surface and in my questioning of the few shops I talked with none of them properly did the same thorough prep. work on the inside.
I am also concerned that the life span of coated headers will not be as long as an uncoated set.This is a trade off I will take.

 

[Paul]

I have had the outside and the inside done on my headers but I did not do a test before to know the difference but the popular opinion is that it does lower the temperatures. The other benefit I was told that the coating keeps more of the energy within the headers allowing for a better exaust velocity and scavenging efect on the other pipes but again I have nothing to support this so don't shoot me down on this one.
Imho it does look much better and stays cleaner than a sprayed coating or a tape wrap but not a cheap option.

Regards

 

[David Briggs]

header coatings

If you are asking about true porceline, as was done on Jaguars years ago, I would say that it was pretty but worthless and not very durable. Ceramic coating as it is done today is quite effective, I have a set of headers on my Tiger, made by JBA 15 years ago, coated at that time and they are still in excellemt condition. I had the headers on my CAV coated in Cerma-tec and they look great and I have noticed a reduction in temperature when I am working on the engine as well as the exhaust cooling off quicker when you shut down.

 

[Phil]

Porcelanized Exhausts

Cliff
I believe Jet Hot is in Pennsylvania. I have had a number of headers coated by them, and I can say the process has gotten better looking in the last couple of years. Whatever condition you send the pipes to them, they will come back coated, so if you have any defects, welds etc. that need to be smoothed out, do that ahead of time. I can say that as was mentioned above don't get oils or detergents on the pipes if they are really hot...just let things cool before washing. I have a set of pipes that have lasted 10 years with the coating, and look pretty good.
Good luck
Phil

 

[Mike Dozier]

Jet-Hot's headquarters is in PA...but their processing plants are in Tempe, AZ and Pascagoula, MS which you'll find out when you call them 1-800-432-3379.
Nice folks, decent prices, good product.

MikeD

 

[Jac Mac]

Just a little off topic , I have found when fabricating headers that it pays to heat cycle them on the car before sending them out for coating, If you dont the coating process which involves heat will normalise the tubing and you will have a tough time fitting them for the first time when you get them back. This is especially important when making individual primary pipe sets like the GT40 with slip fit collectors.

Jac Mac

 

[CliffBeer]

Thank you all - very helpful information. I'm convinced. I'm taking off my headers and sending them out for ceramic coating. A fellow GT40 friend here in Seattle has a lead on a good outfit here locally. I'll report back with results regarding decrease in engine bay temps. Thanks again.

 

Cliff,

I'm not interested in getting into a big argument about this. I know I'm in the minority in stating what I did, but that's fine. I was stupid enough to believe the claims and while my motor was being rebuilt, had the turbo dump pipe coated. To make a short story - my money was refunded. Bit hard for them to argue with the evidence I gave them.

Further empirical data? I have none. What I do have is real data, obtained using thermographic temperature cameras and verified with K-type thermocouple surface temperature measurements. Not only my own testing on my previous car (turbo rotary - they get really hot!), but reports my company has prepared for mining companies on large plant diesels, at considerable expense to them. You see, the holy grail for any diesel plant operator is to get the exhaust temperature below the flash point of hydraulic oil to minimise the chance of flash fire when a hose eventually lets go, spraying oil on something hot! Again, short answer - no recordable difference.

I'd be happy to post some images of coated and uncoated sections of the same exhaust pipe, so you could see for yourself (seeing is believing, right?), but no can do presently due to limited PC access.

I'll say it again, it looks good (the shiny colours anyway), so do it if you want.

 

[Keith]

Interesting. What is the difference in peak primary exhaust temp between a) a high hp gas engine (similar to those found on here), b) a turbo gas engine and c) a high torque low revving working (as opposed to highway operating) diesel motor?

There may be some fundamental differences in the temperature thresholds at which this stuff makes a difference.


Not my subject at all, just curious....

 

[Russ Noble]

IMHO the compelling reason for coating is to achieve longevity of an item that has taken many hours to fabricate. Other benefits like improved appearance (subjective) or better thermal properties (debateable) are purely incidental to the primary benefit. The pipes on my TR7V8, tri Ys that were a nightmare to build, after a seasons racing were starting to flake quite badly in places and I could not see them lasting much more than another couple of seasons. I am sure the coating will extend their life considerably. Money well spent I think.

Cheers

 

[Paul]

The company who does ceramic coatings in South Africa in their advertizing coat one half of a piston and leave the other half uncoated and then apply a torch to both sides and the uncoated side melts while the coated side does not. It seems that it will at the least lengthen the life of a coated exhaust system if nothing else.

Regards

 

[CliffBeer]

Thank you all - great information. Obviously, there's no clear cut consensus as to all, or any, of the advantages here. Despite some convincing evidence to the contrary, there seems to be some limited agreement that there is a thermal benefit to the ceramic coating on the headers - it's certainly debatable. Given that I'm really somewhat desperate to get under hood temps down, I'll go ahead and give it a try - there is a local company here that a GT40 friend gave me a reference to. Appearances are less important to me - I probably prefer the unfinished stainless to be honest, even with "blueing" and discoloration of the pipes from use. I'll run some temperature tests (surface and engine bay) prior to having the coating applied and then also post and we'll see if there's a measurable difference. Thanks again!

 

[fostereast]

Temperature and Heat

Temperature and heat are two different things. I could imagine the external temperature of the headers will still be the same after warming the engine up to steady state, but this does not imply the heat transfer through the pipes will be the same. By adding a barrier of ceramic you are changing the thermal properties of the headers.

I have not looked to see if Jet Hot or someone has published the difference before and after adding a coating, but it should be out there somewhere.