header wrap/ shilds help against hot running engine ?

[frank_ster]

so i tried a sample of ceramic coating on my crf450r motorcross since the exhaust always burns my leg when i'm wearing shorts. i just did a quick spray on to see what it would happen.

and it burns my leg just as much. i didnt media blast the pipe before painting but i don't thing it would affect its temperature keepin in abilities. the paint didn't flake all off a least and that thing has a a glowing red pipe in about 1 min after starting it.

 

[dr_frankenstein]

lol

 

[frank_ster]

any one have a link to low emissivity ceramic paint?

 

[frank_ster]

So I did some research and the surface color and finish has everything to do with emisisivity or infra red radiation .

So a coating that is silver or Chrome will emit 2-5% of the heat of something that is mat black. Mat black being the highest in infra red transmission.

So headers need to be painted in silver Chrome / white to keep the radiation low. Headers painted in black even ceramic will heat the same as uncoated.


There is also convection heat that is common to any color or surface finish. This is like how a electric heater heats air. so the air that passes by the headers are still heated. But that is a small percentage ,

 

[Radke]

I wish I or anyone I'd spoken to in Aus knew that. I have my dump and manifolds coated in black ceramic. I swear it does stuff all but everyone swore by ceramic coating. A lot of guys run the chrome stuff. I've ended up wrapping mine as well, even though I've heard it can speed up rust. Slightly drops ambient temps

 

[dynoman]

So I did some research and the surface color and finish has everything to do with emisisivity or infra red radiation .

So a coating that is silver or Chrome will emit 2-5% of the heat of something that is mat black. Mat black being the highest in infra red transmission.

So headers need to be painted in silver Chrome / white to keep the radiation low. Headers painted in black even ceramic will heat the same as uncoated.


There is also convection heat that is common to any color or surface finish. This is like how a electric heater heats air. so the air that passes by the headers are still heated. But that is a small percentage ,

Did you research SwainTech White Lightning ? Not a paint , true ceramic coating .

 

[frank_ster]

Well again the surface color and finish effect emisivity.

So silver paint and ceramic coating will have the same emisivity for the same color / finish .

Cermaic will endure highertemps before it burns off. Compared to regular paint.

The ceramic coating i got is sprayed on its water based. It sprayed on green, dryed to white , and then using scotch brite it turns to aluminum like finish, and then can be polished.

On my dirtbike i now tried the silver and wow my leg isnt burning ! The pipe feels warm when you put your hand next to it . If you touch it your gonna burn your self.

The ceramic coating isnt meant to be an insulator.

If you look at any new car the heat sheilds are usually silver for the same reasons.

 

[frank_ster]

Did you research SwainTech White Lightning ? Not a paint , true ceramic coating .

Thanks for the link

And very good info.
From what they say their coatings are thicker . And act as actual insultion.
Witch is great.

Likely the white lightning is better. But its also the 10x cost . And not a diy kind of thing.

 

[dynoman]

Thanks for the link

And very good info.
From what they say their coatings are thicker . And act as actual insultion.
Witch is great.

Likely the white lightning is better. But its also the 10x cost . And not a diy kind of thing.

And it usually takes 3 weeks for turn around . It is much thicker , I had my headers , crossover , & downpipe done last May , no run time on it yet .

 

[NY Twin Turbo]

I've glanced through this thread a little. Now for my 2 cents.

I am the king of underhood heat! Call me Mr. Heat-Miser for Christmas.

The trick is to keep heat in the pipe. I have used header wrap in the past. It works. Old original stock motor. Leaky trans fluid on the cross-over soaked it and it caught fire! Had a fire extinguisher and put it out before the fire department did. Never again. Besides, it's plain ugly. I can't stand ugly!

Now I have 2 turbos, 2 downpipes, 2 wastegates and all the tubing to go with it. I spent good money on the Jet-hot chrome like finish for my header coating. They did inside and out. I didn't know if it would work. My engine compartment was still hot. But I found out later how well it worked when I had the coating done again a few years later.

The finish dulled (it still looked OK) and I decided to spend a little less and have someone else coat them. I used Prodigy Coatings in my area. He did a great job but it wasn't his fault he didn't use the stuff Jet-hot uses. They must have an exclusive on the stuff. He had a lot of trouble blasting it off.

Immediately after driving the car, wire loom started melting everywhere. Then twice my Caspers voltage boosters started frying. I left one of my 6 EGT probes loose in the engine compartment and saw ambient temps well above 250 degrees sometimes. Maybe not acurate, but still!

Had too use aluminized fiberglass wire loom in some places and mount the voltage booster under the front of the frame.

Good thing my cooling system is up to the task. On a 95 degree day in July my engine never runs over 175. Even if i'm stuck in traffic.... as always seems to be the case. However, even though my turbos draw air from the underside near the bumper, the throttle body pipe and intake still soak up all that heat. So, air intake temps go way up untill you start moving. Then everything is fine again.

Needed a new curve in my Air temp vs. Fuel Enrichment graph.

Next time I stick with Jet-Hot.

 

[frank_ster]

What my setup looks like now

 

[frank_ster]

Installed

 

[rmar]

Its a pain in the ass to do but you can ceramic coat over a thermal barrier. I've done it many times. But be prepared to pay or have lots of patience and do it at home. If you can get them cured.

And it's still going to burn your leg. Lol

 

[34blazer]

Well again the surface color and finish effect emisivity.

So silver paint and ceramic coating will have the same emisivity for the same color / finish .

Cermaic will endure highertemps before it burns off. Compared to regular paint.

The ceramic coating i got is sprayed on its water based. It sprayed on green, dryed to white , and then using scotch brite it turns to aluminum like finish, and then can be polished.

On my dirtbike i now tried the silver and wow my leg isnt burning ! The pipe feels warm when you put your hand next to it . If you touch it your gonna burn your self.

The ceramic coating isnt meant to be an insulator.

If you look at any new car the heat sheilds are usually silver for the same reasons.

I can tell you that the increase in emissivity using a flat black paint does help a lot, but the caveat to that is only in a certain environment. If there is no air movement in the engine bay, then it would help, but since there is constant movement of air, the results are negligible.

 

[frank_ster]

? Black coatings transmit 50-100 times more infra red radiation

What I have seen is the header is transmitting heat directly to the engine block. Adding to the btu s that the cooling system needs to take away.
I went header wrap last summer and noticed a huge difference.

And so far testing with the ceramic coating it's as good as the header wrap.

And I did the leg burn test with my dirt bike and day and night difference between black and Chrome like finish. Black burns my leg Chrome I feel nothing ,