Benefits of ceramic coating headers for turbos

[stevenlee]

I'm having my motor rebuilt and while it's apart, I'm considering having the DC headers and new Weisco pistons ceramic coated.

Here are my specs:
DC Headers with 10K miles.
1994 motor with new Darton Sleeves and new 93mm Weisco pistons = 3.2 litres.
9.5:1 compression.
Twin HKS 2510 turbos, water-cooled, ball bearing.
Air to water intercooler.
Water/Methanol injection.
(numerous other goodies)

I'd like to hear of any experiences and opinions regarding the benefits or drawbacks with ceramic coating the headers and pistons... and any recommended coatings or shops to do the work. My car is in San Diego.

If I'm going to ceramic coat the headers and/or pistons now is the time for me to have it done.

I'm getting the NSX ready for the 10,000 mile trip to and from NSXPO.

Any comments will be GREATLY APPRECIATED!

 

[angus]

Do it without question. There are no drawbacks that I can think of except it makes for difficult welding for repair or mods later (hard to get it off).

 

[stevenlee]

I'm thinking of having the headers coated on the inside to keep the heat in the airflow and out of the stainless steel pipes. Would there be much advantage to also having them coated on the outside?

How different are the different "brands" of ceramic coatings? What would be a good shop to send them to?

My engine is getting new Weisco pistons. Should the tops of the pistons be ceramic coated too?

 

[Ponyboy]

Hi Steve,

I've had my headers coated inside and out on my Comptech headers - NA application though. Actually, the coater (Airborn Coatings) suggested the inside as I hadn't thought of it previously. IIRC, the coater didn't even charge me for the interior coating.

On any aftermarket header, I'd get it coated inside and out, regardless of application. I'm sure there are many similarities in vendors and their specific coating, however, determining the differences is problematic as each is proprietary. There's Swaintech, aforementioned Airborn, JetHot, just off the top of my head.

IMHO, I wouldn't hesitate to do it again.

 

[Mac Attack]

Maybe it's just me but I would be leery of coating the inside of a header on a turbo'd application. Just the chance of a small piece flaking off could do some damage to the downstream turbo.

If it's a big issue, custom fabricate some heat shields in addition to the exterior ceramic coating.

My $0.02.

Dave

 

[stevenlee]

The reasons I'm considering coating my pipes keep the heat in the exhaust gases and prevent the heat from even getting to the pipes for performance improvements (faster spooling of the turbos) and cooling down the engine bay in general to reduce the intake air temperature. The inside coating should do this most effectively.

I was also wondering if coating the inside of used (10,000 mile) headers would result in poor adhesion that could cause flaking and hope to hear from users with any knowledge or experience with the inside coating and how it holds up under use.

Ponyboy, Were your headers coated when they were new or used?

MacAttack, I am also installing a heat shield on the bottom of my oil pan to reduce the effects of radiant heat from the headers.

 

[BATMANs]

http://nsxprime.com/forum/showpost.php?p=1453510&postcount=24

also did my RX7, sonoma, s10, and GTO.

Loved it. No regrets. I was able to see that the RX7 detonation ceased without any change to the lean tune.

engine bay was cooler for all cars as well as intake temps.

 

[Ponyboy]

Ponyboy, Were your headers coated when they were new or used?

MacAttack, I am also installing a heat shield on the bottom of my oil pan to reduce the effects of radiant heat from the headers.

They were used when coated and I haven't checked for flaking. However, I can say that the exterior finish is perfect. IIRC, the bond strength is something like 9,000+ psi.

FWIW, you can also get your oil pan coated in a heat emissivity coating as well. That will help in minimizing radiant heat and lower oil temps. Although I'm sure you don't want to lower oil temps too much.

 

[Honcho]

Batman- do you have to run different heat range plugs when you coat the combustion chamber and manifolds?

 

[BATMANs]

Batman- do you have to run different heat range plugs when you coat the combustion chamber and manifolds?

I didn't change anything in the FD, but in the GTO and NSX I run a cooler (dunno by how much) NGK Iridium plug.

 

[BATMANs]

They were used when coated and I haven't checked for flaking. However, I can say that the exterior finish is perfect. IIRC, the bond strength is something like 9,000+ psi.

FWIW, you can also get your oil pan coated in a heat emissivity coating as well. That will help in minimizing radiant heat and lower oil temps. Although I'm sure you don't want to lower oil temps too much.

I have checked for flakes on the inside of the headers for all 3 finishes. matte black, near chrome and the white coating. No issues so far.

The heat emissivity coating is something that I haven't tried yet.

The reasons I'm considering coating my pipes keep the heat in the exhaust gases and prevent the heat from even getting to the pipes for performance improvements (faster spooling of the turbos) and cooling down the engine bay in general to reduce the intake air temperature. The inside coating should do this most effectively.

I was also wondering if coating the inside of used (10,000 mile) headers would result in poor adhesion that could cause flaking and hope to hear from users with any knowledge or experience with the inside coating and how it holds up under use.

Ponyboy, Were your headers coated when they were new or used?

MacAttack, I am also installing a heat shield on the bottom of my oil pan to reduce the effects of radiant heat from the headers.

The place that I use (it's a well known Aerospace and Defense company that I can't elaborate) does all of my coatings, so u can imagine the work that they do.

Old or used parts they do some major prep work. Part of it involves beads blasting or walnut shells for softer surface, then they bake all the stuff off at 900F, then do some more prep work, put the coating on (sometimes 2 coatings) and then bake it.

Maybe it's just me but I would be leery of coating the inside of a header on a turbo'd application. Just the chance of a small piece flaking off could do some damage to the downstream turbo.

If it's a big issue, custom fabricate some heat shields in addition to the exterior ceramic coating.

My $0.02.

Dave

Dave, I've even coated the inside of my Turbo snail and waste gate. No failures whatsoever.

 

[DDozier]

As with most things the prep is the key to the final results, I have had all my exhaust and even the turbo housing and heat sheilds coated when I built my turbo system. The only thing I did not have coated was the OEM headers, on the 97+ cars the OEM headers are double walled and I did not see the point in removing them to have them coated. If I had them off the car already I would have gone ahead and had it done anyway. The powder coater had to clean and bake the tubing for three days to cook off any oils or residue, then let them cool, apply the powder then back in the oven to bake on the final finish. I went with a black ceramic finish and love the look. I have had no issues at all, and the under hood temps as well as oil temps are lower than when the car was N/A.

I even used header wrap on the tubing after it was coated for the pipes joining the header to the turbos, If you coat your pipes inside and out I am not sure the wrap is worth it. One thing about the header wrap is that it does have a unique smell when it is hot or if it gets wet then is heated. It took almost 1500 miles before it got to a point were the smell was something I could live with. I did use a silicone sealant on the wrap and it did help to reduce the smell a little, my old car had the headers wrapped and it took a long time for the smell to go away, at least with the sealer it took less time.

Dave

 

[stevenlee]

I've called various coating companies. Here are their comments:

Weisco recommended and referred me to Swain for pistons. Swain charges $38 per piston coated for top thermal and skirt dry lubrication.

Engineering Applications in California estimated $160 for exterior header coating and roughly $100 more for inside thermal coating. They said that they can clean used header pipes and "haven't had any complaints" but didn't offer any other assurances that the inside coating would not fail.

Jet Hot said the other guys have the aluminium/ceramic coatings that are not the best for thermal insulation. Jet Hot can do the outsides of headers for $190-$260 with the aluminum/ceramic coating. They have a more effective E series black exterior coating that handles over 2,500 degrees and would charge $525-$550 for the outside coating.
For coating the insides of headers, they don't guarantee against any coating failure and require a liability waiver be signed. He told me that he would personally coat the interior of the headers for his personal car if the headers were new and that he would not coat the insides of used headers. He said adding the coating to the E series exterior would cost no more than $25 extra.

I guess if I wanted the most effective insulation, I could buy new DC headers and have them coated inside and out. I might be able to sell my used DC headers.

Thanks everyone for the posts and info so far.
I'm still looking for more info and comments to decide if I now want to do the heads and anything else while my engine is being rebuilt.

 

[BATMANs]

.......The powder coater had to clean and bake the tubing for three days to cook off any oils or residue, then let them cool, apply the powder then back in the oven to bake on the final finish. I went with a black ceramic finish and love the look........

Powder and ceramic coating are 2 entirely different products.

Powder application temps are in the 350F~ range where ceramic coating are in the 800F range

 

[BATMANs]

I've called various coating companies. Here are their comments:

Weisco recommended and referred me to Swain for pistons. Swain charges $38 per piston coated for top thermal and skirt dry lubrication.

Swain is used by the Space Shuttle program.

I'm sure business on that end is winding down and they have a surplus of ceramic coating laying around....

 

[L_RAO]

I have used Swain Tech on the following applications:

Intake manifold (lower) on a 5.0 Mustang

Intake manifold on a B18C in a Civic
Piston dome on B18C
Piston skirt on B18C
Header for B18C

Swain Tech is not big on coating the inside of a header; the words out of their mouth are "it's too hard to get an even application"

As to apps I've used, they all were wonderful. With my 5.0 I didn't have to do the ice-pack on top of the manifold trick at the track. My Civic liked to buzz at 8000 RPM all day long at the track without problems.

 

[trainingrevolution]

Steven,

I purchased a set of OEM headers from a NA2, and sent them to Jet-Hot to be coated on 9/14/2009. They charged $235 + $34 shipping. I couldn't be happier, they look great.

-Todd

 

[stevenlee]

Steven,

I purchased a set of OEM headers from a NA2, and sent them to Jet-Hot to be coated on 9/14/2009. They charged $235 + $34 shipping. I couldn't be happier, they look great.

-Todd

Todd,
Were the headers used or new?
Did they coat the insides also?
What coating did they use on the outside?
What color was the coating?
Did you notice any benefits other than appearance?
Thanks for posting you info!

 

[stevenlee]

I was referred to Embee Performance in Santa Ana. They appear to do a lot of government work and do pistons, exhausts, heads and various engine parts with different types of coatings.
Only problem is time. My engine builder wants to start assembly soon and they quote 7-10 days for headers.
Does anyone have experience with Embee Performance or know of a quality shop with a faster turn around time?

 

[BATMANs]

I was referred to Embee Performance in Santa Ana. They appear to do a lot of government work and do pistons, exhausts, heads and various engine parts with different types of coatings.
Only problem is time. My engine builder wants to start assembly soon and they quote 7-10 days for headers.
Does anyone have experience with Embee Performance or know of a quality shop with a faster turn around time?

Don't let ur engine builder pressure u for an extra week. I would totally regret not doing it right - ceramic coating the parts.

 

[stevenlee]

Don't let ur engine builder pressure u for an extra week. I would totally regret not doing it right - ceramic coating the parts.

Batmans, I understand your thinking. I'd agree however it is me who has been urging my builder to get it done soon. I had plans for using the car and a leisurely drive to NSXPO with my wife and visiting friends along the way. I'm kicking my self for not thinking about coating the parts earlier. The more I research it, the more I want to have it done.

I see in your pics that you didn't coat the valves. Was there a reason for that other than cost? If I do have my parts coated, I'm trying to decide on what parts to have done.

 

[BATMANs]

Batmans, I understand your thinking. I'd agree however it is me who has been urging my builder to get it done soon. I had plans for using the car and a leisurely drive to NSXPO with my wife and visiting friends along the way. I'm kicking my self for not thinking about coating the parts earlier. The more I research it, the more I want to have it done.

I see in your pics that you didn't coat the valves. Was there a reason for that other than cost? If I do have my parts coated, I'm trying to decide on what parts to have done.

I left the valves untouched since it would mask the brushed and swirled marks that is designed to better atomize the A/F mixture.

 

[stevenlee]

My engine builder is going to personally drive my parts to Embee Performance in Santa Ana on Monday to get the parts coated. According to the Embee website, they have a very large operation and do military/government work. They will be coating the exhaust inside and out, the pistons tops with a heat barrier and the skirts with a dry film lubricant. If time permits we will also do the heads' combustion chambers and exhaust ports and the valve faces.

My sincere thanks to everyone who posted their comments and experiences on this thread. Thanks to you, my engine should be even better than I was originally planning. Hope to see some of you at NSXPO!

 

[kookoo4nsx]

Steven,

Curious as to your HP goals.

 

[BATMANs]

If you do the intake and exhaust ports it will help smooth out the walls for a smoother air flow which should help maintain port velocities.

Also a coated head will buy you a degree of margin should you run outta coolant, for example.