Painting the intake manifold

[TomoHawk]

People notice my exhaust manifold all the time, even though t's so dark down under the intake. They suggest I get a new one, and have it aluminized or chromed. But if you do that, you might as well do the rest of the exhaust system too.

[FastWoman]

But if you do that, you might as well do the rest of the exhaust system too.

I just did! I had holes in my exhaust and couldn't pass inspection. So now I have a new 2 1/2" MSA Premium aluminized exhaust with Magnaflow mid-pipe SS muffler. The problem is that my exhaust manifold gasket is leaking. Fortunately they didn't catch that on re-inspection.

I'll take another look, but I swear I don't see (or at least notice) the exhaust manifold!

[Z train]

Fastchick-expoxy will not survive the oven.

[TomoHawk]

Normal epoxies don't go to high temperatures, but there are some that will. You just don't find those at the local hardware store.

[FastWoman]

Thanks, Ztrain and Tomo. That would probably rule out the West System epoxy that I use for so many things. (Think boats! )

After a bit of searching, I found this stuff:

http://www.alvinproducts.com/Products/Products.asp?ID=2

... which is good to 1000F. Final curing is done in an oven at 450F. I think that's the stuff!

So I would apply this stuff, slightly thinned, to fare out the manifold's rough surface. I would be able to sand it smooth, probably before heat-curing (to make the job easier).

I'd then want to top-coat ideally with a deep blue metallic paint and/or powder coating. I'd be going with a deep blue because it would be compatible with the car's current silver color, as well as future plans for a candy-apple-red re-paint.

Any thoughts about high temp metallic paints?

I also have another thought: I've been entertaining the notion of inserting a piece of semi-rigid fiberglass duct material (for HVAC ducts) between the heat shield and the lower side of the intake manifold to reduce heat exposure. Not only would that benefit the longevity of the manifold's new finish, but it would also increase HP, decrease vapor locking, increase wiring life, etc. Any thoughts about this idea?

[FastWoman]

How about some of the paints on this page:

http://www.tcpglobal.com/spraypaintdepot/metallic-effects.aspx

There's the anodized look in paints at the bottom -- VHT and Duplicolor. There's also some metal fleck paint at the top, but I don't know what the temperature specs are on it. Then at the very bottom of the page there's a metal fleck overcoat that's meant to be sprayed over a non-metallic base color coat. Hmmmm...

[sblake01]

I also have another thought: I've been entertaining the notion of inserting a piece of semi-rigid fiberglass duct material (for HVAC ducts) between the heat shield and the lower side of the intake manifold to reduce heat exposure. Not only would that benefit the longevity of the manifold's new finish, but it would also increase HP, decrease vapor locking, increase wiring life, etc. Any thoughts about this idea?

What are it's temperature handling capabilities? HVAC ducting doesn't reach the temperatures that are generated by an exhaust manifold.

[Z train]

The factory makes a heat shield,but i'm not sure what models it came on.Having that thermal coated would be a decent alternative.

[FastWoman]

Ztrain, my '78 has a sheet metal heat shield between the manifolds, but I don't yet know its shape.

Steve, The HVAC material might not be "designed" for that temp range, but I believe its composition is glass and aluminum. I don't think there's anything flammable or meltable.

Do either of you (or anyone else) know what temperatures we're dealing with underneath the intake? It sure would be nice to have real numbers, even if they're only approximate!

[Z train]

If you thermal coat the heat shield silver(or better yet-white)that will be your best "bang for the buck".Exhaust gas temperature is over 1300 degrees when it exits the head.

If you are still having a "heat soak" issue after that then something else is"out of sorts".

Edited September 19, 2010 by Z train

[FastWoman]

Thanks, Ztrain. I presume you're talking about this stuff?

http://www.icslinings.com/pdf/Thermal%20Coat%20Brochure.pdf

[cygnusx1]

Brake paint works wonders and stands up to many environments.

Here is my intake painted with silver brake paint from a spray can. This is about 7 years after I painted it and about 10,000 miles later.