1970 s valve covers (black or non painted)

[denson]

I have seen some 1970 s cars with black upper valve covers and some with the valve covers not painted. Mine are black.

Does anyone know which is factory correct?

Thank you.

[beh911]

Black is correct.

[spankie]

I have a 70S since new and it came with silver ones.

Bob

[denson]

Thanks for the help. It seems some say black and some say silver, so I wonder how the car came from the factory. Unless there is a vin number cutoff where Porsche switched from one standard to another, I have to assume all 1970 S cars were made with either black or silver, but I don't think they used both.

The research continues,,,,,,

[edmayo]

I don't recall ever seeing silver, but I do know that sometimes they were the natural mag finish rather than painted, but of course in the seventies most people, like me, were not documenting this stuff! So I couldn't tell you what year (years) this was done or why. When you're doing this as a job you're more concerned with doing it correctly and efficiently, not thinking about who will care 30 years later.

[smedley]

My '70T...purchased new back in the day had plain magnesium which turned funky very quickly. When the cars started coming through in late '72 or '73 from the factory with black coating we all painted them! This is where the compression of time and people finding "original" cars at resale muddies the water. They were raw magnesium...with a dash of cosmolene!

[Tom F.]

I went through a very original and low mileage 1970 E motor recently. It had "raw" magnesium alloy valve covers, no paint. Every 2.4 that I've seen has painted covers. I think that there were both in 71.

[Grady Clay]

My lame recollection is that 1970 was the transition from uncoated magnesium to ‘painted’ black.
The ’70 models saw both types.
The paint was noticeably shiner than the ‘semi-gloss’ of the tin.

Right away, at the first valve adjust, the paint would stick to the cork valve cover gaskets and some would peel off the covers.
The paint was stronger sticking to itself and the gasket than sticking to the magnesium so it would ‘peel’.
Naturally this was only near the bolt holes and cause leaks.
Most needed sanding to get a flat, paint-free surface to seal.

The next phase was the paint coming off at the washers under the Nyloc nuts.
Those needed spot facing.
We got to dipping the new washers in Tectyl to prevent contact corrosion between the alu washer and the mag cover.

The final phase was finding paint on the sump screen from flaking off inside the covers.

The ‘solution’ was to remove all the paint and simply spray the outside.

Remember, this was pre- any aluminum valve covers (save the early 901s) and prior to ‘powdercoat’.

Even when new, the mag covers were not ever ‘silver’.
New from the Factory, they had been dipped-etched/coated to form some gray/brown preservative surface.
This was transformed magnesium, not paint, similar to most other mag castings of the engine.

So….
The 1968 through sometime in ’70 are bare magnesium.
Starting during 1970 production, they are slightly glossier paint than ‘semi-gloss’ of the tin.
I think basic aluminum covers started showing up in about ’75 (including the 930).
The reinforced ‘Turbo’ covers appeared about 1977.
I don’t recall any aluminum covers being painted.

Someone correct me if I have the dates wrong.

Best,
Grady

[edmayo]

Sounds good to me Grady!! I was also there, but wasn't taking notes!!! Now I'm sure you remember the one or two years when they applied a heavy rubber coating to reduce noise, then of course it would partially melt off making a real mess!

[Tom F.]

Needless to say, I'm sure that Grady is right. I'm happy to be nearly as right as him.