C3 Intake Manifold Paint

[Michael H.]

Here's a question for the C3 guys. Everyone knows I'm far from knowledgeable about details on these cars but I do remember something strange that went on in the late 70's, and I think it was shortly after the engine color switched to blue from orange. (when ever that was?) On engines equiped with aluminum intake manifolds, the entire engine, including the aluminum intake, was painted blue. After the engine color was applied, the intake manifold was then painted silver. I don't remember any details but I know for a fact that this occured. It was a screwup at the engine plant, if I remember correctly, and I have no idea how long this went on. Could have been a few days, could have been a few months. It's also possible that the engines were actually shipped to the mill and the silver applied there, but I really don't think this was the case. I just remember several of the guys laughing about it.

Michael

[Joe L.]

Re: C3 Intake Manifold Paint

Michael-----

The change to blue from orange occured in mid-1977---early 77s are orange; later are blue.

An aluminum manifold was first used on L-82 small blocks for the 1978 model year. In 1980-81, aluminum manifolds were used for all Corvette engines. I've seen many ORIGINAL examples of these manifolds that were painted engine color (blue) with no attempt, at all, to apply silver paint over it.

[Tom R.]

Re: C3 Intake Manifold Paint

And its common to find "under-spray" on TVS sensors (when equipped) water outlet housing and where the manifold meets up with the housing. When 78s were first judged, it was believed the overspray on the ground strap was a result of touch-up by a previous owner. With the observation of many low-mileage models, we see many with overspray on the strap and in fact, I recall a few molested engine compartments where the paint had been attempted to be removed from the strap. Since than it's become understood that this overspray on the ground strap was factory.

[Michael H.]

Re: C3 Intake Manifold Paint

Ok, thanks Joe. Wish I had more details about this but I don't remember exactly what the deal was. I clearly remember exactly where I was standing in the plant when I heard this and I'm pretty sure I remember who said it. I don't remember if he said the engine plant was going to add the silver or if they wanted it done at the mill. I suppose there could have been a lot of units built with just the blue, no silver top coat added, before the change was made, if it was made?

Were some of the cars built that year coming through with totally unpainted manifolds or do you think all were painted blue?

Again, I'm far from knowledgeable about late C3 but I thought someone may have noticed and questioned this on original cars.

[Joe L.]

Re: C3 Intake Manifold Paint

Michael-----

Personally, I don't recall ever seeing a natural aluminum manifold during the late C3 period. However, I've not really studied a lot of these cars so it's very possible that there some, maybe even a lot of them.

I've also seen a lot of these manifolds for sale at swap meets. Most of those have been painted blue. Those that were not could have started life as a SERVICE piece. GM sold these for years in SERVICE.