Valve cover resto

regis101 · Post by **regis101** » Sat Jan 10, 2009 12:26 pm

Greetings. Due to changing VC gaskets once a year, I decided to have a second pair on hand.

Picked up a set from the boneyard. Broke out the head porting tool and some scrolls to clean them up.

I noticed that the factory used a thickish black coating on the outside. The inside was also black but maybe this is only ~30 yrs of burnt on oil.

IIRC, the VC's do play a role in heat removal. I used a rough finish on them for the splash and stick thing.

Does anyone know of the proper coating? Radiator paint perhaps? In the end, I could use BBQ paint or something and be none the wiser, hence my question.

This is for a Type 4, 2.0, in our 78 Westy

Thanks

vdubyah73 · Post by **vdubyah73** » Sat Jan 10, 2009 12:59 pm

I've used rattle can BBQ, flat, and gloss. I like 2 coats of brush on rustoleum. Bring the paint and VC's into a warm room the night before you paint. The warm paint will flow much better on the warm steel.

regis101 · Post by **regis101** » Sat Jan 10, 2009 1:15 pm

I googled around. Found this from Eastwood.
http://www.eastwoodco.com/shopping/prod ... ductID=726

Also had some hits about household steam radiators. The reply was to use an oil based paint. Both views mentioned for temps up to or around ~250*

The engine oil temps can be a bit higher. Maybe not at the valve covers. I'm not sure. Perhaps an oil based BBQ paint is good enough. I read about not using latex paint. Also read to not use high temp engine enamels.
Too thick for maximum heat removal on radiators. Just fine for water cooled engine blocks.

I used BBQ paint on the exhaust and with the proper prep it holds up well. My goal there was for looks and rust prevention. My goal with the VC's is heat removal. In the end probably one in the same. I'll search around a bit more.

Post by **Amskeptic** » Sat Jan 10, 2009 10:01 pm

regis101 wrote: I noticed that the factory used a thickish black coating on the outside. The inside was also black but maybe this is only ~30 yrs of burnt on oil.
IIRC, the VC's do play a role in heat removal. I used a rough finish on them for the splash and stick thing.

Does anyone know of the proper coating?

That "thickish black coating" is supposed to be paint, just good old paint. I believe the earlier VWs painted the insides and outsides of valve covers.

You don't really want a rough finish for splash and stick. You want spray and drain. There is nothing to get too excited about as far as cooling properties of valve covers. Your average properly running Type 4 engine runs its oil too damn cold most of the time. If you have reached a point where the valve covers are helping cool the oil, your oil is way too hot to begin with.
Colin

regis101 · Post by **regis101** » Sat Jan 10, 2009 10:14 pm

They're as rough as a 36 grit scroll would get them, which is nothing major.

I ended up going to the Home store and picked up some BBQ paint. Had everything up to a cozy temp and gave 'em a coupla quick coats. Enough to cover with out fear of rusting. New gaskets and I'm on the road.

How to Hot Rod VW Engines by Bill Fisher. Read it about ten yrs ago when i got into the hobby. Page 97, about half way down the first column. It does make some sense. Those Germans are crafty peoples. But in the end, I'm all good with the BBQ paint. The important thing is to stop the oil leak(s)

Hippie · Post by **Hippie** » Sun Jan 11, 2009 9:54 am

Plain old black engine enamel works well for me.

hambone · Post by **hambone** » Sun Jan 11, 2009 10:02 am

Yep, I've used cheap hardware spray gloss black. No problem. Rustoleum seems to spray better though, hardware paint comes out thicker and splattery-ish.
That's one of those "every couple years" jobs. Don't sweat it.

regis101 · Post by **regis101** » Sun Jan 11, 2009 1:50 pm

It goes beyond what type of paint will stick. The heat transfer factor needs to be weighed. ya pays yer money and ya makes yer choices.

Post by **Amskeptic** » Sun Jan 11, 2009 8:43 pm

regis101 wrote:It goes beyond what type of paint will stick. The heat transfer factor needs to be weighed. ya pays yer money and ya makes yer choices.

Here's the thing. (My HVAC hat is "on"). No little piss-ant piece of sheet metal has a chance in hell of "absorbing" heat for any length of time whatsoever. It just can't. If the valve cover does absorb any additional heat due to paint being caked on, it transfers the exact same quantity of heat to the outside just a little later, like measured in seconds.

There is a balance that occurs from the delta T measurement. All it says for our purposes, is that if the outside temp is 70 and the valve cover temp is 190, we have a delta T of 120. If it is 100 outside, the valve cover will absorb heat until the delta T point is reached , say 220. The delta T is the surface area of the valve cover, with the input being the oil splash temperature, and the output being the breeze outside. There is no way in hell for paint to help or hinder the heat from building to the point where the delta T increases to whatever the homeostasis between absorbing/shedding heat is. These numbers are laughably inside the window of normal operation. At 123* out in Baker California in 2005, my valve covers were on average, 250*, the oil temperature was between 230* and 260*. Now what on Earth could my valve covers do to prevent that delta T 130* temperature differential? Nothing. They will help the cool the oil only as much as they can, which is damn close to not much at all.

That said, black is a very important color to choose for engine tins and valve covers. Of the three types of heat energy movement, conduction, convection, and radiation, paint color can help radiation transfer. Unbeknownst to our eyeballs, infrared heat can be reflected with chrome or silver paint. This is not helpful. You want that radiated heat to go right into the paint/metal/paint and be convected away.
Colin

regis101 · Post by **regis101** » Sun Jan 11, 2009 9:56 pm

Here is some reading from Mr. Hoover's sermons.
http://bobhooversblog.blogspot.com/2006 ... paint.html
http://bobhooversblog.blogspot.com/2006 ... -test.html

To my surprise, I shouldn't have used the BBQ paint. It seems that good 'ol flat black is best. Good info about the cast aluminum VC's, also.
Live and learn.

Happy Trails,

chitwnvw · Post by **chitwnvw** » Sun Jan 11, 2009 10:00 pm

I think you are over thinking this. Protect it from rust. Probably don't even need to do this. It's thick metal. Oil is around. Never heard of one rusting through.

regis101 · Post by **regis101** » Sun Jan 11, 2009 10:01 pm

The internet is evil.

chitwnvw · Post by **chitwnvw** » Sun Jan 11, 2009 10:16 pm

regis101 wrote:The internet is evil.

No. I think a spirited discussion is good fun.

But rust needs to be supervised. And a dose of common sense.

You'll be fine. The fact that you have a 2nd pair of VC means you are probably a type A micro manager sort, so you should focus on relaxing if possible. Camp. Drink a good beer, etc.

regis101 · Post by **regis101** » Sun Jan 11, 2009 10:37 pm

chitwnvw wrote:No. I think a spirited discussion is good fun.
The fact that you have a 2nd pair of VC means you are probably a type A micro manager sort,

Wife, kids, and a coupla animals doesn't leave much time for anything. Having a second set is efficient. Adapt and move on.
Camp? Yes. Once a month , at least

chitwnvw · Post by **chitwnvw** » Sun Jan 11, 2009 10:46 pm

regis101 wrote:
Wife, kids, and a coupla animals doesn't leave much time for anything. Having a second set is efficient. Adapt and move on.
Camp? Yes. Once a month , at least

1 wife, 3 kids, 2 dogs, 2 turtles, I am right there. You are doing excellent on the camping.

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Valve cover resto

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