This is a place aprox 2hrs from me here in Canada. According to their site, there is no clearence issues at all for anything. Depending on the part of course, they will use different grades/types of ceramic. Give it a read and it tells you the thickness of the coating and how they use it on pistons etc
http://www.fireballcoatings.com/index.htm

 

My bad, I was thinking of the Jet-Hot coating, which would be far too thick to avoid clearance problems.

 

my guy used the near chrome for the UIM.

I didn't do the TB since I don't know how to take it apart.

 

If im correct, isn't Jet-Hot just the name of the company? They do the same as what the company by me does, its just there name has been used so much its like it has become "the type" of coating. I havent looked into Jet-Hots site, but should it not be the same thickness as Fireball coatings? It is all ceramic and I would think applied the same. So why would Jet hot have clearence issues and Fireball doesnt?? Anyone?

 

No, the two coatings are different. The header coating is actually a metallic/ceramic mix that is sprayed on using a conventional type of paint spray gun, and then oven-cured at over 500 degrees F. The true ceramic coating for internal engine parts is actually applied using a process known as "plasma spraying", which is literally like "welding" the coating onto the surface. A high-intensity electrical arc discharged in an inert gas superheats the ceramic coating powder and literally "shoots" it into the surface to be coated, which forms a sub-metallic bond.

Both coatings insulate against heat, but the plasma sprayed coating is far, far thinner, and forms an actual metallic bond with the material, whereas the header coating is still a "paint" type coating.

 

Ahhhhhh so would the Fireball coatings be plasma, and the Jet-hot be the paint type?

 

It appears that Fireball sells both types of coatings. You cannot use the spray-on/oven-cured metallic ceramic coating on internal engine parts.

 

http://www.airborncoatings.com/

They did my LIM, Y-pipe, Intakes

Jet-Hot 2000 to the DP

Airborn did a great job on all the work as did Jet-Hot. Airborn took about a week with Jet-hot 2 days.

 

.

 

To find out whether you should wrap or coat a part look at the differential temperature between your engine bay and the air inside the parts you want to coat. If the engine bay air is cooler than the air inside your the parts you want to coat, then its not beneficial at all to do so as all that will do is keep the heat inside your parts instead of letting the cooler engine bay air cool it (differential) and allow amounts of heat to disperse out. If you want a coating that is made just to disperse heat then swaintech makes a coating for you that is black in color. Here it is on a oil pan, the owner recorded a 10 degree drop in oil temps just from the coating.
http://www.soundkwest.com/mr2/22oilpansm.jpg

What I have experienced and feel, keep the coatings for the exhaust side of things.

 

I did the jet-hot thing a long time ago...
here is my downpipe jethot coated:

 

Ok to me this makes no sense. He is saying that if the air inside the part is hotter than the engine bay temp then dont coat it so the hot air will dissapate in to the engine bay to cool the part down.

I thought the whole point was to keep engine bay temps down and to keep the hot air inside the parts to get it out of the engine bay.

Also what some other have said about the intake side seems to make sense because they are saying that the part will heat up and then the hot air will not be able to get out. But if the hot air cant get out then how does it get in to the part in the first place?

 

You are correct. Keep engine bay temps down and keep hot air inside the exhaust. Helps with scavenging if I remember correctly and helps turbos boost quicker. Don't remember why turbo boost quicker though...

Correct again with your comments about hot air getting in/out. Air moves and it only gets in from the air filter. Such is the concept of vacuum and air flow and such.

 

Coating the DP is a common thing, and may work. I didn't - I felt the airflow around it and the spacing to the motor was sufficient. Maybe coating the turbo manifold will help, but somehow I think that's a waste.

For everything else you listed, it will not help, IMO. Or at least not enough to make it worthwhile. The best way to lower intake temps is a better flowing intake and larger intercooler.

Dave

 

I think krazywli19's comments were in regards to the intake piping. I think his recommendation makes sense for the intake side:

air filter to turbo(s)? Wrap/coat. The air in the pipes is cooler than the surroundings.
turbo to IC? Don't wrap or coat. The air in the pipes is hotter than their surroundings under boost, which is when you care about the intake temps the most.
IC to TB? Wrap/coat.
UIM/LIM? Wrap/coat.

I'm not saying the benefit is worth the cost for each of these, but rather just trying to clarify which parts it might be beneficial to coat.

The exhaust side is sort of the opposite approach (keep the stuff in the pipes hot), but the stuff in the pipes is always hotter than the engine bay, so wrap/coat it all.

Exhaust manifold? Wrap/coat.
Turbine housing(s)? Wrap/coat.
Downpipe? Wrap/coat.

Think about the FLOW of heat, not just how hot something is likely to get or not get. For instance, you want to keep the air that flows through the intake manifolds cool. That air should be cooler than the environment around the manifold itself, so coating it makes sense. You reduce the flow of heat from the hot engine bay into your intake air. If the manifold is hot, the (thermal barrier) coating will slow it from cooling down. But guess what? It would have been the intake air flowing through it that cooled it, so you don't want that. The goal is really just to slow down the rate at which the heat from around the manifold will be transferred to the intake air that is flowing through it.

I was wondering about coating the top of the manifold with a thermal barrier. Coating the bottom seems like a clear choice since there is a lot of heat under there. Coating the LIM is an easy choice, too, since it is close to the hot exhaust and turbo stuff. But there are coatings designed to help a part shed heat. Would that be of benefit for the top of the manifold? It seems to be the normal approach for V8 manifolds? However, I am still pretty sure that the intercooled air flowing into the manifold is cooler than the air that surrounds the UIM, even on top. That makes me think a thermal barrier coating on the whole manifold (inside and out) would be a good idea.

I am doing a rebuild now and I am planning to try some coatings on various parts while everything is apart, so this thread is particularly timely for me.

I do have a question: Is there any concern over the coating coming off in chips from the insides of the intake runners?

-Max

 

I would say yes especially if the chips are large and metallic.... that's why I would only coat the exterior, since I'd hate to have something like that ratteling around in the rotor houseing or heaven forbid the turbo ...

 

Yeah, but how great are the chances that it actually *would* come off? I agree that it would be very bad if it did.

-Max

 

Yes, sorry if I didnt make it clear. I'm only talking about the intake side. Wrap everything you can on the exhaust side.

 

<QUOTE>I do have a question: Is there any concern over the coating coming off in chips from the insides of the intake runners?</QUOTE>

Good question. It would probably depend upon the coating. I think that is a question for the manufacturer. If it bonds on a semi-molecular level, it would probably NOT flake.

 

Max, your logic is impeccable. Some ceramic coating sites recommend an insulating coat on the underside and a heat dissipating coat on the upper side. I went with insulating inside and out, because I used a phenolic spacer between the UIM and LIM to prevent conduction, and figured the insulation on the inside would prevent heat transfer to the air moving through it. I think it worked.

 

I just spoke with jet hot yesterday.

They said it was only necessary to do the externals on the intake manifolds. Price is somewhere between $150-180. They do internal and external on exhaust side components.

I'm gonna have to search on Mike's phenolic spacer jammy as I have no clue wtf that is

 

Phenolic spacers have had some minor discussion on these boards. It is an insulator between the LIM and UIM. A web search will turn up a fair amount of sites that sell them, but not for RX7s. I think Autospeed did a piece on them a while back.

 

That would address heat issues related to conduction, but not the hot air in the engine bay that heats the UIM and LIM and other components.

Coating it would help with both conduction and convection issues.......

 

Ive always been told not to use the exhaust wraps because they cause heat fatigue and stress on the componet which eventually will lead to the peice cracking or breaking apart.

 

that might be true, but ceramic coating on the inside will reduce the amount of heat that is transferred to the actual metal surface by as much as 35%......