Painting the intake manifold

[FastWoman]

Hi all,

I have a leak in my exhaust and have to pull my manifolds ('78). This seems a good time for cosmetic improvements.

I considered polishing out the intake manifold, but that's a whole lot of work (as it is sand-cast), and polished aluminum really takes a beating here on the coast. Instead, I think it would look great with a painted finish, something like this:

http://atlanticz.ca/zclub/techtips/intake/normal_throttlelink2.jpg

I'd love to see other pictures about how this might be done. I have the less attractive '78 manifold with the webbing between the ports. I suppose the webbing is a practical thing, keeping more of the exhaust heat off of the injectors. I was thinking I could black out the webbing and paint the rest a color. This hammered blue isn't bad. Ideas?

Of course there's the practical matter of how to fair out the exhaust and which paint to use. There's not a whole lot of heat to deal with, except of course near the head, where the intake and exhaust ports are adjacent to each other. I was thinking of using thickened epoxy to fair out the rough aluminum. Would this hold up to the heat? And then after sanding the epoxy smooth, what paint would be best?

Thanks for your suggestions!

Peace,

Sarah

[mlc240z]

Can't help you with any recommendations (definitely not my area of expertise) but I agree, that blue does look good.

[steve91tt]

I was thinking of using thickened epoxy to fair out the rough aluminum. Would this hold up to the heat? And then after sanding the epoxy smooth

I think the epoxy should stand up fairly well to under hood temperatures and it should stick fine to the aluminum if you prep the surface correctly and don't put it on too thick. If it's too thick then the difference in the expansion of the aluminum compared to the epoxy will cause stress at the interface during temperature cycles. In other words if it's too thick it could delaminate but this is the case with any hard polymer coating on a heat cycled metal.

The epoxy will likely yellow so you will have to topcoat with something that is colorfast in a high temperature environment. You might try engine enamel but make sure that you sand the epoxy first to give the enamel a low gloss surface to stick to.

Good luck! I look forward to seeing photos.

[pwd]

Go to your local Powder Coater and ask them about their hi-temp products. It will be available in a variety of colors. It's very durable and will stand up to the heat.

[twsutt]

I second pwd's opinion. Definately go with powder coating. That's the hottest part of the engine bay, right above the exhaust header.

[TomoHawk]

I'm not a fan of powder coating, so all I did to clean up my intake was to clean it by scrubbing with some degreaser then an etching wheel cleaner. It brightened up significantly and people noticed and liked it. I also enlarged the drain holes so they wouldn't get plugged so fast. It already has a heat shield, so I don't worry much about the heat from the exhaust.

Do you have plans for the exhaust manifold? Some local rodders will blast it clean, then have it plasma-coated with aluminum, and polish.

Edited September 16, 2010 by TomoHawk

[Mikez73]

I'd go with thermal coating. Functional and looks good. This is mine :

[Z train]

Eastwood makes a good coating for the manifold.As far as podercoating goes,the normal stuff melts at 400 degrees.

There is stuff called "Toon bright" that will clean up the intake good.

[ZCurves]

I am not sure if Powder Coating would last since there is a bunch of heat where it bolts to the head. I am sure that there is a high heat coating available like a ceramic, but there may not be very good color choices.

Have you thought of Anodized Aluminum? Since the Intake is Aluminum that might make a cool alternative. It can be done with some cool colors and wont be affected by the heat.

Whatever you end up doing, now would be the time to mill out around the Ports and Throttle Body (if it's EFI) to increase air flow and weld up any unused fittings, etc.

FWIW: I coated my Exhaust Manifold with the Eastwood High-Temp Stainless and it looks really fantastic and has stayed that way for a long time.

Finally - Post Pics of before and after. We all need something to live vicariously through!!

Edited September 16, 2010 by ZCurves

[Mikez73]

Whatever you end up doing, now would be the time to mill out around the Ports and Throttle Body (if it's EFI) to increase air flow...

Waste of time and money IMHO.

[Z train]

Waste of time and money IMHO.

Port matching and smoothing out "runner boogers" is never a waste of time.

[FastWoman]

Thanks for all your suggestions, guys! Wow, there are a lot of useful products out there!

I looked at some examples of high temp powder coatings, and they're gorgeous. The only catch is that they're done on glossy surfaces, and getting the manifold smooth is going to take either a whole lot of sanding and polishing or fairing out with an epoxy filler.

Mike, how long did it take for you to polish out your intake manifold prior to ceramic coating?

I also stumbled across Eastwood high temp ceramic engine paints:

http://www.jcwhitney.com/high-temperature-ceramic-engine-paints/p2023816.jcwx#

... which look great, but I would obviously need to start with bright, polished metal. I presume this is a similar formulation to the stainless finish, Andrew? Can I expect pretty good adhesion out of it?

I wonder how it would look on rough aluminum... Hmmmm....

It would be nice to clean up the valve cover and do it in the same finish.

Tomo, aluminizing the exhaust manifold sounds pretty cool, except that it's so buried you hardly see it. I was thinking of a high temp black exhaust paint instead.

Anodizing... Hmmm... Sounds interesting. Can that be done on rough metal?

Whatever I choose, it needs to be something that doesn't take excessive amounts of time. I don't want my car down for too long, as we live on low-lying ground in hurricane country. I don't want to have to evacuate the car by tow truck!

Thanks again, guys!

Edited September 17, 2010 by FastWoman