C2 Exhaust Manifolds to heads

[Jim R.]

Is it best to just bolt them up as the factory did, use some silicone or use gaskets.

[Jimmy G.]

Re: C2 Exhaust Manifolds to heads

Gaskets are a pain and eventually blow out - although it take a fair amount of time

Silicone or other sealers are a waste of time

Machine the manifold and install as the factory did (if it is warped)

[Joe L.]

Re: C2 Exhaust Manifolds to heads

Is it best to just bolt them up as the factory did, use some silicone or use gaskets.

Jim------

It depends. The factory originally used no gaskets or sealer of any kind. However, the heads and manifolds were new at that time. Over the years of use, the manifolds may "warp" or otherwise become "distorted". This is why many SERVICE gasket sets include exhaust manifold-to-cylinder head gaskets.

You can check the manifolds and cylinder head seating surfaces with a precision straight edge. If they're straight you can bolt up the manifolds to the heads just like the factory did. If not, I recommend having the manifold surface machined (the manifold is almost always the culprit) rather than using gaskets or any sort of sealer.

[Domenic T.]

Re: C2 Exhaust Manifolds to heads

Jim,
I use a flat stone, like the large stones that some use to sharpen knives with. The large ones are the ones to use on the head surfaces and the manifolds and that works just fine. I would imagine that there is something that could be wiped on very thin that would help. I have used copper coat spray and it seemed to do the job.
Otherwise insuring that both surfaces are flat will seal them.

Dom

[Michael H.]

Re: C2 Exhaust Manifolds to heads

Don't forget to torque the manifold bolts.

Mike

[Stuart F.]

Re: C2 Exhaust Manifolds to heads

And use some new French locks - properly.

Stu Fox