250se, original color for valve cover....
 

I always thought these were just alloy color, perhaps with a clear coat, from the factory.

Someone told me no, they were painted silver and it eventually wears off. Just like the cadmium plating wears off the injection lines.

I don't know about this. Anyone have any info on just how the valve covers and intake manifolds were protected, or not, from the factory?

I am going to have some parts vapor blasted so they will look new, or newish, but should they get a coat of silver paint or a clear coat?

I've never heard of Mercedes painting valve covers. So I'm listening to this thread in case it actually happened back then. But I really doubt it.

Clear satin or matte finish coat.

Are you saying you know what Mercedes did? Or that you would recommend that to the original poster....?

Both. The original "coating" was just a spray on corrosion/oxidation resister. I've never seen it last longer than the first or second time the engine was cleaned. More of a "wax" than an actual sealant. At least that is all I have ever seen on new, crated engines from Mother Benz.

All the valve covers I've seen on Mercedes were made from cast aluminum with no permanent coating of any sort.

I think there might have been an original coating but just to protect the parts during the long sea voyage to wherever they were going.

I know Porsche's came new, in the late 60's and early 70's, with a coating of some type that was a very light green in color. But this was due to the high magnesium content. Once the car was in use then just expelled oil and whatnot would protect the transmission cases and engine cases. But uncoated the slightest bit of salt water would slowly eat them away.

I have been working on this and I really think that there was no paint or coating used at the time because nothing existed that would have been right for the job. Not for long term use, anyway.

But I will very likely lightly spray a clear coat, or that is have it done since I am not that talented and I want it to look good. The painters tell me the big danger to clear coat is UV light, not something you normally find under the hood.

Any other comment on this would be welcome. Anyone know what concours cars are treated with besides a lot of care?

I did check with a guy I know who has a large car collection. He was no help since none of his cars are driven, just restored and displayed.

I thought the factory put wax-based cosmoline on the valve covers.

...but that would offer temporary protection only, right? Sort of like the blue stuff we see on new white wall tires...?

Yeah, it's just so that they wouldn't oxidize before the car was delivered. It typically would come off in short time, but I've seen baked-on remnants of it on high-mileage cars as well. If it wasn't washed off early in the car's life, it would get stuck on there almost permanently.

Corrosion of head covers isn't an issue in most conditions. They only time I've really seen it be an issue is if I car was parked for decades in a very damp environment or out by the ocean.

It's no different than the aluminum heads, intake manifolds, upper oil pans, or thermostat housings--they were just raw aluminum from the factory and sometimes coated with cosmoline.

I know VW did this to protect the cars from the sea voyage. But this applied to the entire car.

In 1971 I took a guy to pick up his new Super Beetle. One rear fender looked different. As it turns out the dealership was moving the car around the yard and dented that fender. They replaced it with one from another car. But no one washed off the cosmoline (?)

So they took it back to make-ready and cleaned it up. They threw in a set of floor mats, those fiber mat types they used back then, to ease things over.