All,
Title says it all - what are the Pros/Cons??
Anyone with real world experience?

Thanks All!!

Wally.

Pros-it looks nicer
oil doesn't penetrate the aluminum discoloring it so it stays looking nicer

I don't know of any cons besides cost...I had mine done for about 80 dollars

Exactly what I'm thinking....Thank you!
I've spoken with a few guys that say it may hold in heat too much??
Any issue there?

Exactly what I'm thinking....Thank you!
I've spoken with a few guys that say it may hold in heat too much??
Any issue there? [/quote]
I had one intake manifold and one set of valve covers powder coated black, NEVER AGAIN The reason being was the heat retention by the powder coating, both of those parts where on my bracket car and they were horribly hot to touch after a run
I can't imagine how hot they would have been a on street car after driving several miles
Anadizing aluminum (to a color you like) doesn't do that so maybe that is a better option for you

I had one intake manifold and one set of valve covers powder coated black, NEVER AGAIN The reason being was the heat retention by the powder coating, both of those parts where on my bracket car and they were horribly hot to touch after a run
I can't imagine how hot they would have been a on street car after driving several miles
Anadizing aluminum (to a color you like) doesn't do that so maybe that is a better option for you [/quote]

Anodizing an intake manifold???
I’ve never seen much less than heard of that but it makes sense.
Any pics?

http://www.zenithcasting.com/anodizing-for-aluminum-casting.html

Read the part about thermal conductivity.

No pictures as I have not had that done nor do I know any one that has , sorry.
I had 9 secondPhils pistons hard anodize after they got beat up in the motor I built for him instead of buying new pistons, he had Ray Barton hone his block after I sent the pistons back to him to get the clearances correct
That process did add a little more diameter onto the skirts as well as make them tougher Most of the Top Fuel motors have that done to their pistons to help them live longer, seeing that gave me the idea to have his done

The 340 6 pack manifold on my Challenger T/A is powdercoated, has been for about 40 years now, zero issues, no discoloration in the heat crossover, no heat retention issues, etc, etc

I think your "heat" issue was with the color choice, not the technique employed, Black coatings of any kind used on objects that generate heat, radiate heat more effectively in black, however items that don't generate heat painted black, will absorb heat more readily... black coatings in an engine compartment can be a double edge sword when it comes to absorbing or radiating heat

That set of parts was horrible about retaining heat in them for a long time, I think the plastic powder coating sealed up the aluminum trapping the heat inside the motor
I ran that car with several different motors in it and that set of valve covers and intake manifold was the only ones that retained the heat that way that long
I paint all my race motors black with high heat engine paint with aluminum heads, if they end up with iron heads I paint them black also

Use the silver coating like they put on headers.

Ceramic coating??

I had my Barton manifold powder coated a while back just b/c I hated the way it looked. Had it done in a color so it would hopefully look brand new for a long time. I think it turned out great. Can't really comment on heat issues, haven't really noticed any difference.

coated...

uncoated...

We've had no issue. However single stage urethane seems to hold up better. I have one painted 25 years ago. The one in this pic was 16 years ago.
Doug

I ran a production powder coating facility for almost 20 years. There are a couple misconceptions being passed around in this thread.

First off, powder coating is not plastic. It does not 'seal' the surface it's applied to. Powder is paint, with a mechanical bond to the surface it's sprayed on. The bond is not appreciably different than liquid paints. It is not a molecular bond. A cured powder coating surface still has some permeability.

Powder is generally a thicker coating than liquid pint. Normal mfr's recommended film thickness for a smooth finish tends to be in the 2.5 - 3.5 mil range. Some coaters will put it on heavier, but that does nothing to improve the performance of the powder.

Anodizing is a very thin, but very hard coating. It tends to work better on extruded aluminum than it does on castings, mostly because of the inherent porosity in an aluminum casting.

We did a lot of intake manifolds, valve covers, timing covers, engine blocks, motorcycle engine side covers, rocker covers, cylinders, etc, etc. Generally engine heat will not discolor a properly cured powder coat finish.

However, powders a made in a number of different chemistries, for varying reasons. Some are more resistant to chemicals, some more resistant to UV, and other variables. Epoxy powders tend to provide the best chemical resistance, but there are not a lot of fancy colors formulated in epoxy.

The one category powder has not completely caught up to is headers and exhaust manifolds. High temp powders generally can't quite keep up with header temps on a hard running engine. There's also a lot of silicone in the formula for heat resistance, which makes it finicky and more challenging to handle/spray. We'd done some headers that held up for years perfectly while others failed miserably. Ceramic coatings tend to be your best bet for this stuff.

It would be best to discuss with your local coater to make sure they understand the environment the part will see. As for cost, much of the amount charged is for the masking of the surfaces that are not to be coated. Masking involves a more specialized tape than the 3M masking tape you see at body shops. It's more difficult to work with and tough to get to conform to irregular profiles or surfaces. Second cost driver is the actual powder you select. Powders can run from $3.00/pd to $25.00/pd depending on what it is that's used. Material costs comprise about 15-16% of the bill, so you can see that quadrupling the material cost will have an appreciable impact on the final bill.

Finally, talk to your coater to make sure you're clear on how to properly clean/maintain the finish. I actually had a Harley owner come in mad as heck because he sprayed EZ Off oven cleaner on his hot engine and it streaked the gray wrinkle side covers we'd painted for him.

That’s a lot of good info Peabody!!
Thank you very much!
I think I’m going to go with powder coating.
Of course the car isn’t painted yet so it will be awhile before it’s tested, but I will for sure report on it.

Had the intake coated a 'natural aluminum' color, and the valley tray an offset color. No "heat retention" issues, no more staining or oxidation worries, and easy to wipe clean. No regrets at all. Will have the new valve covers and motor plate done eventually.

Tell me about your alternator and bracket...;)

Black paint or powder coat does not "generate" heat. That is just plain R-O-N-G!

Black absorbs radiant heat and emits heat better than other colors but not by as great a margin as people think.

The thermal conductivity of aluminum is greater than paint or epoxy coatings. So, if one adds a layer of paint the heat will not travel through the combined thickness as well. There is from time to time an argument of whether to paint radiators and the real answer is most radiators are sized large enough that taking away a couple of percent of their capacity by painting does not materially affect the radiator's capacity.

Ideally, one would put a thermal barrier INSIDE the intake manifold runner to slow the heat transfer from either the underhood temps, or the higher temps of the engine conducted from cylinder heads into the intake. This would tend to maximize power. Keeping the heat in the manifold may maximize fuel efficiency.

R.