Warped manifold

[Erik Barrett]

Here’s a job I don’t much like doing but has to happen sometimes. I don’t have time on this job to wait a week for a new manifold so I had to straighten this one. It was worth doing because it is in pretty good shape other than the warp. It was tweaked so badly I essentially had to break it in two and weld it back together straight. I use a powder spray torch for this kind of work. Pays for itself every time I use it.

[JTT3]

Well done Erik

[Joe Bell]

You can straighten them with out breaking them, just time and heat, and weight of wrench if you rush it , it will break!

[SurfCityGene]

Yup, I was amazed the first time I saw it for myself!! There are some good videos showing how just the weight of a combination wrench sitting on a jack screw will allow the heated manifold to move back in perfect alignment. The heat does have to be applied in the center area but as it heats up you can see the wrench slowly move slightly pushing it back closer to perfect. When it quits moving you just have to move the heat to another area. It's quite something to see.

We made a fixture from a piece of 6" channel with a flat bar lip on one side and a 3/4 nut welded to the opposite with a piece of all thread and some clamps to hold it flat. Never had one break.

[Art M]

Is it worth straightening an original Ford exhaust manifold. I bought a new replacement and set the original one aside. I thought about scrapping it based on previous posts.

Art Mirtes

[Allan]

My scrapping point is if the thread is past being serviceable. Then I check the degree of bend. Many can be fitted in their warped state by using one ore two off-set gland rings. The others which require straightening still occupy shelf space in my workshop.
A new one fits well, but it looks new. In some applications that is not something some will be happy with. They are not an exact replica either, so that too does not suit some folks.

Allan from down under.

[Art M]

Allen,
My original Ford exhaust manifold has very good threads. The end port is drooped by about 1/16 inch. At the time I didn't want to risk destroying an original so I solved my immediate problem with money by buying an aftermarket one.
An original might be valuable to someone who is into show competition and it might be necessary for a Stynosky award.

Art Mirtes

[speedytinc]

1/16 - 1/8 drop is a great candidate for straightening. I just did one for an original 15 with 1/8"
I find anything over 1/4" is about 50/50 chance of success without a crack.

[Allan]

Art, just a 1/16" bend is an ideal candidate for an offset gland ring. No need to straighten it. I have posted photos showing how to do this, but Others will have to direct you to the post.

Allan from down under