C2 small block exhaust manifold gaskets

[Steve D.]

Link to picture below (because I haven't learned how to post the actual picture yet)

What is the function of the gasket with 3 bolt slots. The instructions with the gaskets said to place one on the right rear and one on the left front

Steve

http://www.villagephotos.com/pubbrowse.asp?folder_id=1138194

[Duke W.]

Re: C2 small block exhaust manifold gaskets

With the possible exception of very early SBs, GM never used gaskets between the exhaust manifold and head.

They can possibly seal up a leak due to warpage, but you are better off having the surfaces skimmed as required to true them up and leave the gaskets off.

Duke

[Mike McKown]

Re: C2 small block exhaust manifold gaskets

Some V-8 manifolds had two ears for bolts at the locations mentioned. I think it was the 305 engine in the 80's. I can't remember the reason for it either. Matter of fact, I can't remember whether these engines used gaskets but I'm thinking they did.

[John H.]

Re: C2 small block exhaust manifold gaskets

Cast iron Chevy V-8 exhaust manifolds never used gaskets, but the gasket set manufacturers feel compelled to include them anyway; if your manifold mating surfaces are anywhere near flat, you don't need them.

[Mike McKown]

Re: C2 small block exhaust manifold gaskets

Yeah, I have a whole bag full of these manifold gaskets. Anybody need some?

[Michael H.]

Re: C2 small block exhaust manifold gaskets

Best and fastest way I can think of to crack an exhaust manifold is to use the gaskets supplied with every engine overhaul gasket set. Wonder why they continue to send these along. Must be a division of the company that makes exhaust manifolds. Sure fire way to break off an ear of a big block manifold.

[Patrick H.]

Re: C2 small block exhaust manifold gaskets

I agree.

I didn't have my exhaust manifolds touched with my engine rebuild in 1996, and I went through a set of exhaust gaskets each year until just a few years ago when I had the manifolds skimmed. I then ditched the gaskets, and NO leaks. Never should have used them.

Patrick

[Tracy C.]

You can resurface the manifolds yourself easily

All you need is about 36" of flat surface and some 80 grit belts for a 3 inch wide belt sander. Cut the belts so you can lay them out flat. Use double sided carpet tape or spray adhesive to stick them down on the flat surface.

If you have access to a surface table, this is best. I didn't but I improvised and bought a piece of granite "backsplash" stone (the kind used against the wall on your kitchen cabinets) Secure it in place on your workbench, stick the sandpaper on and then sand back and forth until you are removing metal uniformly across the entire surface of the manifold.

Cast iron is pretty soft and this will only take about 15 minutes of work.

Cheaper than paying a machine some to surface grind your expensive pieces and you don't need to worry about them being dropped or otherwise hosed up.

good luck,
tc