39 V12 Intake Gasket

[zephyrdave]

A strange thing has happened to the intake gasket. After driving the car to cruise nights and shows all summer, I never noticed before, but it looks like the intake gasket has grown in length. It is sticking out at both ends of the intake. This is the first summer of driving after the car and engine were restored. I have a PCV valve connected from the original vent hole to the intake manifold just below carb. I'm thinking crankcase pressure shouldn't be a factor with a PCV connected. It appears to have stretched, but how can this be possible?

[Beltfed]

That is just plain weird. The intake should be under vacuum so it would be sucked in, not out. Have you checked the torque on the intake bolts? What, if anything, did you use on the gasket when installed? Did you perform a vacuum manifold check when installed, and now? How is it running? Sorry for all the questions but I think there will be more unless one of the "gear heads" here has seen this before.

[peecher]

I wonder what that gasket might have done around the intake ports where it really matters?

[zephyrdave]

I'm going to pull the intake carefully to see what the gasket looks like. If it is indeed stretched, then the car will need an exorcist.

[Beltfed]

I ask an old mechanic your question. He said "that creep doesn't surprise me, especially on the long intake of the v12. Do a re-torque on the bolts and a vacuum check. If going for show points trim off the excess."

There you have it. I, not him, think if your vacuum is good then "no worry, mate".

[zephyrdave]

Well, I removed the intake and found that the gasket had delaminated and somehow the delaminated parts (front and rear of manifold) pushed their way out. It is a paper gasket that I think came in a gasket set. I bought a new gasket that is laminated with a wire mesh, something like a head gasket. Maybe the solid paper one was from China.