My neighbor says that back when he worked at a Ford dealership in the 60's, they had a problem with all the exhaust manifolds that they pulled off of sixes. He said that you could lay them down for a few days when you where working on the engine and the cast iron manifolds would warp to the point of being unusable. He said that the exhaust manifold on my car would do the same thing while I am doing my super six conversion. I plan on having my manifold off for a while so I can smooth out all of the pits and repaint it so it will look good. Will it warp while I have it off and is there anyway to prevent that from happening.

By the way, what type of exhaust paint do you guys recommend? I have been looking at the exhaust paints offered by Eastwood.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Naw the manifold won't warp just sitting there. Manfiolds have been known to warp due to their length and the heat going through them - you pull them off, they spring into their place, and you can't get them back on. But if your manifolds are in good ocnidition when you pull them off the engine, they will be ok when you put htem back on if all your doing is some cleanup work on them (no welding)

Well my manifolds don't leak now, I was just afraid they would be warped when they sat for a while then I would really be screwed. While I have the manifold out I need to ream out the outlet so I can fit a 2 1/4 head pipe into it. Do I need to put this thing in a jig while I have it out to keep from warping? My neighbor has one but it is for Ford inline manifolds.

The worst ones I have ever seen for warping was the Y-shaped manifolds that go on a small block chivvy. Those things look like a pretzel when they set out for a while.

I am trying to get this thing ready my Senior prom. I don't want to show in my tired old D-150!

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Could somebody at least tell me what causes manifolds, slant or not, to warp?

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Warp speed . doint worry about a Slant Six manifold warping unless the engine caught on fire. Bagel Beam me Up to warp speed Thanks Possum










Using A Tennessee Moonshiner To Burn A Bagel

Is that english??????????

The manifolds don't warp from just sitting around a shop. They MAY warp while sitting, but it's because of internal stresses built up in the casting process, machining, and lots of heat cycles. When you take the manifold loose, it is freer to move. It could take a while to relax.
This kind of thing is why some racers prefer "seasoned" blocks to fresh castings (in engines where such things are available). They "move" or change shape less as the stresses are relieved.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Nope that is redneck ps do you live close to Bagel doint know about yall Illinois boys. Thanks Possum











Using A Tennessee Moonshiner To Burn A Bagel

It's always been my understanding that if a manifold is going to warp it'll do it as soon as you pull it off.

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70 Dart, 360, 727

This is an example of a phenomenon known in technical circles as "the inherent cussedness of inanimate objects".

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Buy a new manifold, 109.00 at 1AAuto.com, not a bad repro.

I am going to sandblast my exhaust manifold so I can remove all of the rust for better paint adhesion. How do I remove the counterweight (round one, 1974) from the exhaust flapper so I can remove the little spring behind it. Or will it hurt the spring if I sandblast the manifold with it still installed.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

Easier: Lye-based oven cleaner (Easy-Off original type, not "fume free").
You don't—not without destroying the manifold heat control valve and requiring a new assembly.
No, just don't focus a lot of sand on it.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I always protect "delicate" parts from sandblasting with duct tape.

Jerry

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There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

I personally have never had a warped Manifold on a /Six. I have not heard of one on a /Six ever. Ford Sixes are notorious for having really thin Exhaust Manifolds and they do warp. But not from just sitting around. If the Manifold, in question, had been checked the second it came off the engine, the warpage would have been noted at that time.

I did have to take a set of /Six Manifolds in and have them Surfaced true at the mounting area. I dropped my original Exhaust manifold and broke it. (Never put them on top of your work surface, the floor is a much safer place to set them.) I pulled another one from the reclamation yard, mounted it to the intake (Bolts finger tight, new gasket) and mounted the assembly to the engine. Then I tightened all the bolts evenly to the spec of 30 ft. lbs. Then I drove the car for a week, then removed the assembly and took it to the machine shop. They removed .005 on the first cut, this almost cleaned and trued the surfaces exactly to each other. On the fine cut he took another .005 inches. Oooo! Pretty!!!! Them I put the assembly back on the engine and ran it for seven years, trouble free. I could have run it the way it was, I just tend to be a worrier and wanted to make sure. Also, the car was a 1964 and the manifold I got was for a 1971, so I was concerned anyway.