BB service valve cover gaskets -- why silver ?

[Wayne M.]

I've got two sets of BB upper engine gaskets (head, intake, etc.) from the late '60s, and notice that the cork valve cover gaskets are silver. Is this an anti-stick feature ?

I realize that the cork gaskets on '65 steel valve covers (ie. BB and base/L75 small blocks should exhibit orange overspray, but if the coverage wasn't complete, would you see evidence of bare cork or silver on the big blocks ?

And what's the best method of installing new gaskets ? Glue to valve cover, and spread a thin film of oil on the side that contacts the cast iron head, to facilitate future removal ?

[Clem Z.]

Re: BB service valve cover gaskets -- why silver ?

I've got two sets of BB upper engine gaskets (head, intake, etc.) from the late '60s, and notice that the cork valve cover gaskets are silver. Is this an anti-stick feature ?

I realize that the cork gaskets on '65 steel valve covers (ie. BB and base/L75 small blocks should exhibit orange overspray, but if the coverage wasn't complete, would you see evidence of bare cork or silver on the big blocks ?

And what's the best method of installing new gaskets ? Glue to valve cover, and spread a thin film of oil on the side that contacts the cast iron head, to facilitate future removal ?

the silver stuff was a thermal setting adhesive as it was all most imposable to get those covers off of a 65 BBC with out a hammer

[Joe L.]

Re: BB service valve cover gaskets -- why silver ?

I've got two sets of BB upper engine gaskets (head, intake, etc.) from the late '60s, and notice that the cork valve cover gaskets are silver. Is this an anti-stick feature ?

I realize that the cork gaskets on '65 steel valve covers (ie. BB and base/L75 small blocks should exhibit orange overspray, but if the coverage wasn't complete, would you see evidence of bare cork or silver on the big blocks ?

And what's the best method of installing new gaskets ? Glue to valve cover, and spread a thin film of oil on the side that contacts the cast iron head, to facilitate future removal ?

Wayne------



I believe the PRODUCTION gaskets also used the silver-like coating. I vaguely recall that my 1966 and 1968 Chevelle SS 396 having such gaskets when new. All GM SERVICE gaskets for many years were this way, too.

I always thought the silver-like coating was a sealer of some sort (like using aluminum paint on head gaskets).

[Clem Z.]

Re: BB service valve cover gaskets -- why silver ?

Wayne------



I believe the PRODUCTION gaskets also used the silver-like coating. I vaguely recall that my 1966 and 1968 Chevelle SS 396 having such gaskets when new. All GM SERVICE gaskets for many years were this way, too.

I always thought the silver-like coating was a sealer of some sort (like using aluminum paint on head gaskets).

i think it was also used to prevent the oil from weeping thru the pure cork. once they got to corkprene gaskets the weeping was not a problem.

[Larry M.]

Re: BB service valve cover gaskets -- why silver ?

Wayne:

I was always told that the silver coating was paint that was used to seal the cork and prevent oil bleed-thru (ie. the dreaded valve/rocker cover oil leak). I rember "tech articles" from this period instructing you to apply silver paint to the cork gaskets if they were bare/natural.

I have always used 3M Yellow Super Weatherstrip Adhesive and applied it to the valve cover side of the gasket, installed the gasket to the valve cover, and then let it set up awhile before installing on the engine. Prior to installing on the engine I used white grease or Vaseline to coat the other side that contacts the head. This was to prevent sticking....as we often had solid-lifter cams and were always removing the valve covers to readjust the valves.

Then lightly tighten down on the attaching bolts/screws with a 1/4 inch drive ratchet or medium screwdriver to avoid over-torqueing.

Things improved a lot with the availability and use of MR GASKET cork/rubber composition gaskets.

Larry

[Ronald L.]

Re: BB service valve cover gaskets -- why silver ?

Wayne - on the question of silver show through. That was always one of my questions. How could you see silver if the engine was properly painted. I recall people saying the judges expect to see these silver tabs at the ends of the covers. The real issue is they should be painted.

These things tend to leak. Clean clean and then re clean, follow suggestions here and another BB oil leak thread from today on permatex recommendations, everyone has a favorite.

[Joel F.]

Re: BB service valve cover gaskets -- why silver ?

Wayne - on the question of silver show through. That was always one of my questions. How could you see silver if the engine was properly painted. I recall people saying the judges expect to see these silver tabs at the ends of the covers. The real issue is they should be painted.

These things tend to leak. Clean clean and then re clean, follow suggestions here and another BB oil leak thread from today on permatex recommendations, everyone has a favorite.

I believe you would be able to see some silver on the tabs if you use a mirror and look at them from the underside. Imagine a line working spraying the engine from the top. They are not concerned with spraying under every nook and cranny, and very little paint would get under that area

[Ronald L.]

Re: BB service valve cover gaskets -- why silver ?

Joel,

That I agree with 100%. The top side though from the pics from Tonawanda - orange or more orange.