Exhaust Manifold Gasket

[waterzap]

What is the consensus on exhaust manfold gaskets?
I know originally most engines come without gaskets. However once you take things apart, what about then?

Mechanic said to just use high temp RTV, gaskets inhibit heat transfer. Someone else said the more expensive copper ones are good (if car is not for show), and someone else said just to use the regular cheap ones.
I have a set of copper gaskets. Why would I NOT want to use them?

[Big Fins]

Do you have an exhaust leak? If not, why mess with it?

If so, you answered your own question on the usage of the copper gaskets.

[waterzap]

The exhaust gaskets blew out…previous owner. So took off the manifolds, took them to a shop to have them machined. I think they took off too much metal, the edges did seem a bit thin. Just used some high temp RTV, but cracked within 5 min of driving. So got another set. NOT going to take it to the shop again.

[Matt Innocenzi]

Waldo,

I am going through a similar experience (see my posts on exhaust).  Unlike you, I was foolish and did not get my exhaust manifolds machined to make them true.  I learned my lesson.

As for the gaskets, I have always used gaskets and will always use a gasket between any metal to metal joint.  No questions asked.  The RTV sealant, if used at all for exhaust manifolds, should be the copper one and used as a belts and suspenders. 

Take the manifold off, get a set of new gaskets, and try them dry.  That should solve your problem.

Matt

[SixDucks]

My .02

  I have always used pure copper for exhaust gaskets and never had a leak. Dead soft copper seals surface imperfections and won't burn out. I would be inclined to spray both sides of the gasket with copper coat. You may substitute high temp RTV as I have heard this works well but my experiences have been with copper gaskets and spray on copper coat.
Terry

[waterzap]

Im in the camp of copper gaskets with copper spray at the moment. Installed one that way so far. Hope it works
Thanks

[Coupe]

I had tried all the basic exhaust gaskets on my '62 with no success then posted my predicament here. A member recommended  Remflex gaskets and it solved the problem without the machining manifold.

http://catalog.remflex.com/

[waterzap]

Thanks. Ill use the copper ones now, seeing I have them. If that does not work, will try the remflex. Only thought I have is how it transfers heat?
Heard that the gasket has to trasfer heat to keep the manifold cooler.. Copper is pretty good at that, not sure about the graphite gaskets.

[waterzap]

Taking the bolts off on the new manifold, where the manifold goes the exhaust, broke one off. Put it in evaporust for a day, the one came out, other one broke off.
So not taking it back to the shop (never again), I now have to get the broken bolt out.
I already drilled a decent size hole through the broken off bolt. Can now either use easy out, or my other thought was, to take some JB Weld, and glue another grade 8 bolt inside the hole. Thought gluing might be the safer bet, because there is so much area, the bolt should sit well.

[SixDucks]

 
The safest thing to do is weld a nut to the end of the stud, heat the stud cherry red,allow to cool for 2-3 mins then carefully turn the stud out. This method has almost always been successful for me.

   Terry

[mgbeda]

I wanted to ask the same question about manifold gaskets yes/no.  I am doing the final reassembly on my '76 SDV engine.

I also want to know if I would lose judging points if I have exhaust manifold gaskets.

Thanks,

-mB