Exhaust Manifolds

[Rusty76]

Ok last one of the night! Exhaust manifolds, as you can see these are the originals from my 360 that I'm rebuilding. They are rusty but seem solid. Can a guy just clean these babies up, spray a little high temp paint on and reuse them?
I'm not into throwing money at problems that don't exist. Says the guy who bought a beater...
Thanks again.. Happy Thanksgiving...

image0 by , on Flickr

[chubbinius]

If they are solid and the faces are flat/smooth/true, just wire brush them well, degrease and then hit with a good hi-tech paint (rust reformer like por-15/rustileum manifold paint isn't too pricey). Good luck

[tgreese]

Looks good to me. As mentioned, the sealing surface must be flat and smooth - no warping or erosion by prior exhaust leaks allowed. Check for flatness with a good machinist's ruler. Your local machine shop can flatten them if they have any sealing surface problems. Those too-long bolts sticking out of the AI ports looks kinda goofy - there are cleaner solutions.

Unless you buy the expensive manifold paint from Eastwood (which they claim will last), and bead blast first, no paint is going to stay put on a hot exhaust manifold. I say clean with a wire brush, spray with black barbeque paint so that it looks nice when assembled, take a few pics of your nice clean engine and run it.

[rang-a-stang]

I used this stuff on a Geo Metro Exhaust manifold and it worked pretty well.

https://www.eastwood.com/calyx-manifold-coating-3-oz.html

[Rusty76]

Ok thanks. Funny how you get tunnel vision. I didn't even think about smaller bolt.
I did think maybe to stack a couple extra washers.

Two things I didn't do, which I probably should is anti seize the bolts and maybe a little rtv on the bolts to stop oil from coming up?

tgreese thanks, I wondered what those too long bolts are for. Apparently nothing.
I dont know if I can even get them out.

a long time ago when I thought working on the engine was just around the corner I ordered some high heat paint from eastwoods.
I will double check and make sure everything is flat and good to go before I bolt up.
I notice the gaskets are thick. Must be to accommodate the swings in temperature?

Thanks Again

[GWNashville]

Exhaust manifold

I went over manifolds with a wire brush and then cleaned mine with Calyx manifold cleaner from Eastwood and they look pretty good. Originally worse than yours.

[tgreese]

...
tgreese thanks, I wondered what those too long bolts are for. Apparently nothing.
I dont know if I can even get them out.
...

The bolts plug the air injection ports (smog pump plumbing). If they come out, you could remove them, cut them shorter and put them back.

Not an endorsement - just an example https://www.teamgrandwagoneer.com/ex...-gw-1974-1991/ Oil pan drain plugs are also sometimes used.

The factory used no gaskets, iron on iron. The aftermarket composite gaskets blow out pretty regularly. The factory used a steel ring at the heat riser too - no composition donut gasket.

If you have to use gaskets, the Remflex gaskets are said to be good.

[Cliff]

Rusty - I removed the AIR manifold on my 81 Wag and installed bolts with JB Weld on the threads. After 2 days curing I cut the bolts flush with the manifold and much to my surprise, it lasted. Never leaked, and after smoothing and painting looked like a non-AIR manifold. Don't use JB Quik - use the real stuff.

[rang-a-stang]

I used copper (or maybe they were aluminum?) crush washers from banjo bolts to seal mine up. Mine we rusty and had tiny little leaks between them. Super annoying.

GWNashville, those manifolds are puuuuuuurdeeeee!!!!

[GWNashville]

I'm gonna buy those plugs from TGW. Thanks for suggestion Tgreese.

[Rusty76]

Thanks for all the great info. Ive got a game plan now!

[Rusty76]

I cleaned them up and sprayed with some eastwood stuff.
Hopefully it lasts long enough to get some nice pictures of the whole
deal back into the bay.

Those bolts are locked in. I couldn't get them out. Maybe I should have just cut flush.

IMG_0332 by , on Flickr