The Stovebolt Site Forums The Shop Area Engine Shop exhaust manifold issue

I removed my cylinder head on my GMC 228 due to a coolant issue, now that I have reinstalled the head and manifolds the 2,3 and 4,5 exhaust manifold doesnt touch the head. I did try to tighten it but you can see the gaskets still dont seal the surfaces.

Because I thought the Stovebolt Gods would smile on me I started the engine thinking it would magically fix itself but there is a LARGE exhaust leak at these 2 area's.

How do I remedy this? Can I install thicker gaskets for just this portion of the exhaust? Do I have to have my intake and exhaust manifolds machined?

The intake manifold seals perfectly.

thank you in advance.

Try loosening the exhaust manifold from the intake. That should give you enuf slack to bring it up tight. If not,,its probably machine shop time.

how likely is it that those bolts will break? I havent tried to loosen them because they look real ugly.

Sounds like you have something not lined up. If I remember right my 216 had round sleeves that lined up with grooves in the manifold & head. If your 228 is the same you may not have the sleeves in the grooves and it's keeping your manifold from seating right. I'm sure if I'm wrong on that someone will correct me.

Don't get in a hurry and force anything. If it was right before, it's still right now. You just have something a lil' bit tweaked thats keeping it from setting. Walk away from it, take a break, and come back later and look at it again. When you figure it out, it'll amaze you that it's something simple that you may be overlooking. Been there, done that. Many a time.
Good luck.

Pletch , you are correct in assuming they might break. Chances are they will. If they are studs with nuts you can heat the nuts to a slight glow & they will come off. If it,s a bolt it will most likely break off. Check everything like the guy.s have said. If it,s pretty close you can use Permatex copper RTV sealer on the gasket.

Pletch,

Did you have three rings/sleeves for aligning the intake manifold ports to the head? As Tiny said, these can easily bind if not aligned properly. Loosen up the manifold bolts and see if the sleeves/rings are aligned properly.

Yes, you could try two sets of manifold gaskets, but my bet is that the alignment rings are misaligned.

Tim

I'm with the others on the manifold alignment. Don't try to separate the intake and exhaust sections. I don't remember if GMC used the gland rings/sleeves in the intake ports, but if so, they are difficult to align. If the gland rings are necessary, you can see a counter-bore in the intake port of the head, and also a matching counter-bore in the manifold. If you don't have the counter-bores, don't try to use the rings.

If you had the rings when you disassembled the head, and you are using them, I think your trouble is purely alignment. Loosen the manifold quite a bit and move things around. If the exhaust pipe is still connected to the manifold, it is all the harder to get everything aligned. Your problem was common on Chevrolet engines with the gland rings. It just takes proper alignment to get everything together. And you get better at it with practice.

I might also add that there are/were quite a few Chevrolet engines running around without those rings. And some GMCs too.

Harvester