Manifold Sealant

[Trapdoor2]

Not specifically on an A (because, well, this is my first one), but I've always used a thin coat of permatex copper seal on gasketed interfaces that see high heat. Even when machined to mate, I like having both belt and suspenders...

It certainly doesn't hurt.

 

[old ugly]

How about for the engine blocks that are not so good? Mine has some pitting, especially around #4 where it has an exhaust leak. Tried filling with high heat epoxy, using copper sealant, and the copper gaskets but no luck. I can try being more aggressive with the epoxy but not sure if I'm just going to make things worse by doing so.

that area is so hot. unless there is a sealer for industrial applications i don't know if off the shelf sealers and epoxies will ever stand up.

i wonder if the side of the block could be surfaced/decked by a machine shop. of course that means a tear down. and depends on how deep the pits are.

just thinking out loud

 

[rotorwrench]

Manifolds are infamous for warping under extreme heat over time. The blocks that were the late design used gland rings to aid in holding back the flange pressures of the hot gasses. A lot depends on fit which can be checked prior to installation. If fit is bad then no amount of sealant will stop a blow out. Old manifolds are generally drooped on the exit end. Warpage, if not too far off, can torque up and seal. Modern manufacturers generally use a formed steel gasket or a steel composition gasket. I've used copper on air cooled aircraft and motorcycle engines and had many blow outs.

The model A manifold gaskets available are either sandwich type copper, composition steel, or even some weird composition types of unknown material. Choices are not real good but at least the manifold can be removed without too much trouble after a blow out.

I don't use any sealant but I do use the gland rings. A compressible steel gasket would likely last the longest. It's your choice. Originality versus reliability I guess. If I did use anything on them, it would likely be rattle can aluminum pigment paint. I prefer that over copper coat for flathead head gaskets.