DO NOT powder coat valve covers!!

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I have been fighting a oil leak for two weeks and I found the problem today. The PO had the upper valve covers powder coated to make them look pretty.
Well when you powder coat them the heat from the process warps them real bad! I spent over an hour sanding them flat. I used a piece of glass with sandpaper on it. And guess what NO MORE OIL LEAK
I just thought you guys would like to know

[Jim Richards]

Same experience with powder coating the intake valve covers. Never again!

[Jubbie]

I did a crackle/wrinkle coat that works without heat. It turned out pretty nice.

[Shuie]

My valve covers got dropped off at the powder coaters last friday. Thanks for the heads up on how to fix them

[speedingbullitt]

I heard from some one on this post?? That there is a low temp powder coating process used on wheels. Any one have any info on this??

[john walker's workshop]

i would hazard a guess that they were already warped before the process. most of them are. put any valve cover on a sheet of 80 grit on a flat surface, scrub a few times and see.

[jpnovak]

Two things to mention. I completely agree with John on this. Probably warped to begin with. Second it is usually not a good idea to PC the seal mating surface. this usually is not completely smooth and will prevent the seal from seating.

[Henry Schmidt]

POWDER COATING LIKE EVERYTHING ELSE WORKS WHEN DONE PROPERLY
We powder coat all of our valve covers. The trick when doing any process to your engine and engine parts is to check the work before installing it. With valve covers, we always resurface them before installation.
The real problem with powder coating is coating the entire cover ( inside and out). The coating on the inside tends to flake off in the engine. ( very common on C2 valve covers)
Never powder coat the inside.

For those of you with warped valve cover and little or no budget for new ones, send them over and we'll surface them for you. ( the option is buying a $5000 belt sander) $7ea

Powder coat and resurface $15 each. We stock most types of valve covers so turn around can be same day. Silver or black
Customer colors take 1 week.

[MotoSook]

Nice set up Henry..

As another sample: I had my intake valve covers powdercoated with some other parts and I gave very good instructions to the coater...never had a problem with leaks since I installed them.

[fintstone]

I watched Henry do mine. Only took a few seconds on that sanding beast. Not a leak anywhere....and they stay clean enough to eat off.

[Nitrometano]

If you want to paint the valve covers, buy marine engine spray paint and paint the covers from the color that you want. The paint does't came off because the marine engine paint is for aluminum, magnesium or iron.

[NevenM]

Hi

From what I've seen on my 73 engine I think the factory powder coated the top covers but did not coat the inside where it was was part of the cam cavity, They are not only covers but 'oil deflectors' as the spray bar has holes pointed at the top covers then the oil 'drizzles' onto the intake rocker (or out onto the floor!) Optimistic design!

Neven

[F1BADUDE]

Originally posted by speedingbullitt
I heard from some one on this post?? That there is a low temp powder coating process used on wheels. Any one have any info on this??

I wouldn't recomend low temp powder coat as it will not withstand the heat of your engine.
Standard powder coat you can bake as low as 325 DEG. This shouldn't have any warping effect. I can't see a cover warping even at temps of 375 - 425 which is where most comercial powder coaters bake.
In general, powder coat is around 0.25 to 0.5 mm thick and surface is uneven. This is what probably causes your leaking.
Were having a he!! of a time on a product we are developeing. Chrysler requires us to powder coat every thing and it is a pain in the @$$ putting parts together after process. I can't tell you how many expensive parts I have tossed trying to drive a bolt into a powder coated weld nut. Even at Class 10.9, 10% of the bolts either hit torque 1/2 way in or they strip.
If you can find someone to e-coat them, this is much much thinner and more evenly distributed. It's a little less shinny though and not nearly as durable.
A guy that does some powder coat for me ay work also does anodizing. Do you guys think that would look cool on my covers?

[NevenM]

Hi

A guy that does some powder coat for me ay work also does anodizing. Do you guys think that would look cool on my covers?

Unfortunately you cannot anodise castings as they are porous and certainly not magnesium

Neven

[F1BADUDE]

Originally posted by NevenM
Hi



Unfortunately you cannot anodise castings as they are porous and certainly not magnesium

Neven

Bummer

I'm going to check on Monday. I'm wondering if E-coat bath is corrosive to magnesium.

[rover67]

you are ALWAYS supposed to sand the covers flat when you rebuild the motor anyways... Its just what you do.
I powder coat valve covers (masking off inside sections) and I have never had any problems. Just make it habit to flattenthe covers befor they go back on.

[strokher racing]

Powder coat can be cured at 340 but it is best to cure at 400. This will not warp the covers. I have powder coated rubber bushings in control arms with no problems. If you have overspray after powder coating you will want to use MEK to clean them. THis is the best stuff you can get. I have coated more stuff than I care to mention.
Eric Hood

[Cad.Guy]

Mine worked like a champ.
I lapped them first
Bead blasted and powder coated them Red with a clear top coat.
Re lapped to get the minor overspray off and they were fine.

[911pcars]

Any thick coating will inhibit heat transfer to a certain degree. Powder is a relatively thick paint coating (about 6-12 mils). YMMV.

[Cad.Guy]

There is relatively little cooling from the valve covers.
They are insulated by gaskets, and pocket of hot oily air.
There is minimal cooling air flow over them.
If they were critical to cooling they would be part of the cooling air flow and finned like the cylinder jugs.