Ceramic Coating

[kentSC]

I have a question about Ceramic Coating on the exhaust system. I have recently removed my engine for some minor fix ups (oil leaks and clutch), and want to tidy it up before it goes back in. I have a lot of items earmarked for powder coating, but I recently heard about ceramic coating exhausts as it resists staining from the heat. I have also heard that the ceramic coating retains a lot of heat and I wanted to know if that is true as the air cooled engine works best without heat.

I have removed the heat exchanger tinware, and I feel there are four options to refurb the exhaust:
1. leave them as they are (ugly and rusted looking) - not preferred
2. Paint them with heat proof paint
3. Powder coat them, or
4. Ceramic coat them.

Does anyone have any views on this question?

Thanks

KentSC

[kees]

I'm interested too.....

[schamp]

I would think that with the ceramic coating the exhaust gas would stay hotter longer and may exit quicker than without. Spencer

[safe]

Yes.
5. Ditch the crap and get some SSI, or similar.

Either that or nb.1.

I dont think the rest of the alternatives would be worth it.

POR 15 has a heat resistant paint_on_rust paint, could be an option.

[rsa]

Low budget option. Prep and spray with BBQ high heat paint or high heat block paint from napa.

[Evans, Marv]

Ceramic coating works best for headers, since they are simple pipes without any of the other crap in between like you have. As I understand it, they have to clean the pipes out with media or something before they apply the ceramic coating. I'd try something like media blasting them & apinting with heat resistant paint or the heat resistant POR15.

[911pcars]

I'd consider SSI's, but there's still a substantial cost difference compared with the options described so far.

In general, I'd recommend ceramic coating. Exterior surface temperature will be lower thus reducing heat transfer to the engine. I've measured exh. pipe surface temps of 400ºF under the lower valve cover (early 911), and that was only at idle. I'll bet it's higher with a cat. system. Who needs more heat to reject from the cooling system? If pieces are also coated internally, CC will extend the life of the base material, whether it be plain steel or stainless. Prepping the surface is important. Your system must be sand blasted to clean base material. The CC shop should provide this service.

Sherwood

[randywebb]

ditto to what Sherwood said - SSIs if you can afford; ceramic coating otherwise (if the cost diff. is big down there)

that assumes you have no emissions regs in Aust. on your SC (it is an SC right?)


- do not expect any magic from a ceramic coating of the headers - much less the mufflers; the real value of ceramics is when they are used as inserts right in the exhaust ports (doesn't the 993 do this?) -- things are already pretty cool by the time the gases reach the headers, relatively speaking

also, not sure what you mean by "the air cooled engine works best without heat."

[safe]

What would an estimate be on mediablasting, prepping and ceramic coating be on a pair of heat exchangers and mufflers?
I looked up the price for cc on a pair of v8 headers, I cant remember how much, but it wasn't that cheap.

[john70t]

One of the coaters I liked was http://www.jet-hot.com/Pages/coatings.html. They quoted around $350-400 for both a few years ago plus sent a cheesy video. Pricey, but the temperature range was pretty high. There are lots of companies, but get the specs.
Pelican also sells a inexpensive HeetSheet shield which helps protect the lower heads from radiating heat, but total enclosure is a sure bet.

[schamp]

There is a product called Engine Heat Protection which is a tape that is wrapped around the pipes. Do a search for EHP. I know it is used in a lot of bus converions to keep the heat down on the rear of a bus where the master bedroom usually is. Can't have to much info. Good luck.

[afterburn 549]

you can also do tops of pistons and the like.........................

[911pcars]

"There is a product called Engine Heat Protection which is a tape that is wrapped around the pipes."

Header tapes can do that. However, they can cause the pipes to overheat or trap condensation and create corrosion. In either case, it can shorten the life of the wrapped pipes.

Sherwood

[oneblueyedog]

Por 15 makes a header paint. I painted some 914 1.7 headers about 10 years ago. I saw them at a swap meet 2 years ago and I was amazed how well they looked. I painted my premuff (exactly like yours) and it has turned a nice tan color like stainless steel does. Not pitting. The paint is called "factory manifold gray".

Ceramic coating is pretty amazing. On this 914/6 I saw, the owner told me to put my hand near the headers to feel the radiant heat, but to be careful around the muffler because that was not coated. The car had been sitting for 10 minutes after a run. The muffler would have seared flesh on contact. The headers were coated in and out and I could touch them briefly.

There is actually a coating that radiates heat that you can theoretically put on the fins of your cylinders. It's a thermal dispersant coating to help shed heat. I heard it was very expensive. It's a product used to paint military vehicles for some type of IR camoflage. Not sure how that works.

Black BBQ flat paint is an old VW racer trick. You coat the jugs and that helps dissipate heat better. I tried it on a 914 and it made the jugs look better at least.

[schamp]

I used cc on the pistons and valves on my 6.5 turbo diesel. Also the crossover pipe. I raised the hp from 190 to over 300 and had to protect the engine and get the heat out as best we could. Its worked so far. I would agree with Sherwood on the condensation and possible problems down the road. I will use EHP on my motorcoach but I don't drive it much and figure I will be long time gone before the exhaust pipes could rust out. Good luck.

[randywebb]

coating that radiates heat...

all coatings radiate heat -- the one I've seen does claim itself to be a thermal dispersant

a place near Portland does it, but they don't know how it works or anything really

it is no more spendy than a powder-coating, so I had it done to my oil tank -- just for kicks; it is always easier to get satisfaction in life if your expectations are low...

[oneblueyedog]

all coatings radiate heat --

to some degree...

I'm tired, adios.

[dfink]

In another life I worked in a boiler plant for a Hospital. We used a latex paint that had ceramic beads in it to paint the inside doors of the boilers and the outside of the preheat tanks. The tanks were just steel tanks running at as close to 212* as you can get atmospheric and you could put your hand on the outside of the tank without burning it. The tiny ceramic beads were teriffic insulators. It didn't look very good as it was kind of rough but I bet it would really keep the heat in the pipes. Mix the beads with some sort of really high temp paint and it might allow getting rid of heat shield. 20 years ago stuff was about $50 a gallon. Don't know what it would be now. Just a thought.....

[carmad]

I did my HE and muffler in ceramic for about $300, they media blasted them and came out great. They have been very durable and have not chipped or cracked on my 930 which were done about 3 years ago.
Some pics

[Evans, Marv]

Randy,
I think the coating company you are thinking about is Performance Coatings. I had them do a bunch of stuff for me several years ago, when I was getting stuff together for my 2.7L.