Seriously warped manifold

[65standard]

The exhaust manifold on my 1970 truck is completely warped. I put the two outer bolts in and the middle doesn’t even come close to lining up. Anyone ever see a manifold get warped like this. I know why the last bolt wasn’t used when I took it off. It is about 1/2” too high. I can get all bolts in except the last one but that leave the rear exhaust port open and compromises the other ports on the intake too.

[demian5]

Get a jack and a long 2x4 and make it happen captain!

[65standard]

Cast iron doesn’t bend like steel. It will just crack if I do that

[Astro-Balls]

Looks like New Manifold Time..

[65standard]

Yes, for I can find one.

[65standard]

I can only find a 250 exhaust manifold for a C/10. I have a C/20. Will it fit. The seller says it won’t fit my C/20.

[Boog]

I can see a new split header and dual pipes out the back old school style happening here.

[GRX]

Originally Posted by Boog

I can see a new split header and dual pipes out the back old school style happening here.

^^ This if you can swing it. The inline actually sounds pretty good when you split the pulses. Nothing like the buzz of a single tube. Or you could just switch to an integrated head

[edit]
And I assume you are leaving the bottom bolts loose while tightening manifolds to head.

[Steeveedee]

Originally Posted by 65standard

I can only find a 250 exhaust manifold for a C/10. I have a C/20. Will it fit. The seller says it won’t fit my C/20.

Chisel him down for the manifold price, telling him you're willing to risk it. C/10 to C/whatever, it'll fit.

Unless it's warped, too!

[kwmech]

Don't see any reason why it won't fit the C20

[72 tigger]

It should fit

It seems to me you should not have a problem finding an original manifold; post a WTB ad and I bet you will get a lot of action.

[kazoocruiser]

bad post, sorry

[kazoocruiser]

You might get some help from one or more of these. If you can find an oven big enough to heat the manifold, it might allow you to heat it enough to reform it. I know that when I would do engine rebuilding, the NAPA near me had an oven that was big enough to burn off the deposits on an engine block.


Do a search on Ebay for manifold spreader. I would have posted a link but it didn't work.

[Grumpy old man]

Did you remove the exhaust when pulling the head or just move it out of the way still attached to the exhaust manifold .If the exhaust pipe is still attached that could be why the intake wont align correctly . the intake and exhaust manifolds should be pulled apart and cleaned of carbon deposits before being reassembled with new gasket and before reinstall to the head .

[kazoocruiser]

Saw this in another thread. Got money?

https://www.shop.cliffordperformance...250-292_c4.htm

[Wrenchbender Ret]

I used to service a fleet that had many 292 engines. That was a common problem. The only way is to get another manifold. The C10 will fit. They generally are in better shape then the 20-30 series trucks as they are not worked as hard. The early models had 2 bolt ex. flange & latter ones had 3. Either can be used if you change the flange.
The spreader tool mentioned is for v-8 manifolds.
George

[65standard]

I don’t see how I can adjust this and make it seal the ports.
The rear exhaust port is bent up about 7/16”

[65standard]

The engine was together missing the last exhaust bolt. I see why now. I can’t put it back together knowing the port is open and not sealed.

[Steeveedee]

Correct me if I'm wrong, somebody. I thought that the last holes, front and back, only had a stud in them- no nuts. Not that it makes too much difference in this case.

[kazoocruiser]

Are you absolutely sure that your gasket isn't upside down? From your first picture, where you have two bolts at the ends, it looks like the middle four ports are getting minimal coverage that would be removed if the gasket was flipped.

[65standard]

It fits the head that way. If a flip it, it’s much worse and I won’t get any bolts it other than the two outer ones.

[kazoocruiser]

Thank you for posting that follow up to clarify kind of what you are dealing with. In looking at all of your pictures and your descriptions, my take-away is that you can install the outer two exhaust manifold bolts to at least hang the manifold. From that point, your gasket is not covering the ports. All of the other securing mechanisms of the manifolds are used with flanges that allow for alignment of the intake manifold independent of the exhaust, correct? I could be wrong, but it kind of looks like you could cut the gasket in sections and align them with the ports and then tighten the flanges to pinch them into place.

[Warrens69GMC]

The gasket should have a flat side and a rounded side. The flat side goes against the head.

Flat side in this pic is tan, rounded is silver

[65standard]

The gasket only fits the head this way. Cutting in sections will not help the manifold align with the head. This gaskets has the smooth side toward the manifold. Can’t reverse it.

Also the intake and exhaust manifolds bolt together. There are 3 bolts under the carb area. I can’t undo these as there will be a big gaping exhaust leak. The top of the exhaust manifold is wide open as to preheat the carburetor.

I thought the same thing, just separate the two manifold to align them to the head better.