Exhaust manifold straightening

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Model T Ford Forum: Forum 2015: Exhaust manifold straightening
Top of pagePrevious messageNext messageBottom of page Link to this message  By Bill Anziani on Saturday, December 19, 2015 - 11:08 am:

Anyone know of someone who can straighten out an exhaust manifold. Mine has #4 port just off a little from the other three ports


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mike Bender Tulsa Oklahoma on Saturday, December 19, 2015 - 12:53 pm:

By the time you ship both directions and what it cost to straighten you're better of just buying and new one. I found that the re-pop is of qood quality.

I have straighten them in the past and for the cost it is not worth the time. IMO

Of course if it is an early rare one than that would be a different story.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rick Goelz-Knoxville,TN on Saturday, December 19, 2015 - 01:04 pm:

Bill, our club has a jig but like Mike says it's cheaper to buy a new one, it takes a tremendous amount of gas and oxygen to straighten one.

Rick


Top of pagePrevious messageNext messageBottom of page Link to this message  By john kuehn on Saturday, December 19, 2015 - 02:49 pm:

Same here on this end. I built a jig out of a piece of channel iron using pics on a T website as a guide.

I already had a Oxy-acetylene rig. But the cost of using up the gas to heat up the manifold is not cost effective plus the time in building a jig if you don't have the material to do it beforehand.

If I need another exhaust manifold I'll just buy a new one. They look to be pretty good.

I used the flat asbestos manifold gaskets to compensate for a warped manifold for a good while and they worked OK for me.

To each his own.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John C Codman on Saturday, December 19, 2015 - 04:19 pm:

I bought a new one from Lang's. I can't tell the difference between the repro and the original (except of course, the new one isn't warped and fits with all the rings and gaskets.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Saturday, December 19, 2015 - 05:32 pm:

I bought some the "seconds" manifolds Snyder's was selling, and they look like a real quality part (haven't yet installed one, but I'm assuming (uh oh!) that with all the work done to make the patterns, set up the machining, etc. that they will fit. The flaws that made these "seconds" were insignificant enough for me; most originals are way more cosmetically "bad" than these (and usually warped)!
The present-day cost of O2 and gas makes these a real bargain, IMHO--and I'm CHEAP!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Saturday, December 19, 2015 - 05:41 pm:

I have used Chaffin's new manifolds on tow of my cars and they work very well. Just remember to install the steel glands between the block and manifold. Those rings will keep the manifold in place when it gets hot and prevent sagging of the rear end.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Saturday, December 19, 2015 - 06:26 pm:

No scratch and dent at Snyders right now.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Val Soupios on Saturday, December 19, 2015 - 06:34 pm:

Costs more in gas and oxygen to straighten them than it does to buy a new one. I built a jig, took every warped one I had on the shelf and straightened them all. It is time consuming and costly. If I wasn't trying to save the two manifolds off my '10 & '12 T's it would not have been worth the effort.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Leck - Ohio on Saturday, December 19, 2015 - 06:43 pm:

Regarding the scratch and dent manifolds at Snyders...last spring I hand picked the one I wanted and there were a few dozen to paw through. I'd be surprised if they were all gone unless someone grabbed them all up. Might want to call to see if they still have any left.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Saturday, December 19, 2015 - 07:32 pm:

Their website as of today says that there is nothing available in their scratch 'n dent section, but hey, it never hurts to call them and ask! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dewey, N. California on Saturday, December 19, 2015 - 08:25 pm:

When someone here posted about them a while ago, I ordered them right away, even though I'm still not ready to use them--figured they wouldn't last long. Guess I was right
Sorta like Larry's exhaust pipes, figured I'd better get me one while they're around! Not to say he might do another run, depends on how quickly these go!
Most model T new parts are short production runs, ya snooze, ya lose!
:-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry Horlick in Penn Valley, CA on Monday, December 21, 2015 - 12:44 pm:

I used my material, time, and welding gas to make up a manifold straightener. Next I carefully heated up a bent manifold. Did you know it is possible to burn right through a carefully heated manifold? I practiced on my worst one. I am not going to start a manifold straightening business!

My jig is in the scrap pile. It is surely available for anyone who needs to melt him some manifold!

TH


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Tuesday, December 22, 2015 - 01:22 am:

I got mine skimmed when the head was done.


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Stroud on Tuesday, December 22, 2015 - 01:40 am:

Kevin, that's not what they're talking about. They are talking about taking out the downward bend that is in many manifolds. Dave


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie Spokane, WA on Tuesday, December 22, 2015 - 06:38 am:

When I put together one of my Montana 500 motors - for some reason I decided that a straightened original manifold would be better than a re-pop, so I made a jig and straightened some manifolds. One problem I had was - although I could get the four holes lined up, the spacing was off. For example, the spacing between the first and second hole might be a 1/16" too wide and the middle two a 1/16" too narrow. They then would not fit with the close tolerance solid gland rings that I was using.

http://www.mtfca.com/discus/messages/506218/536166.html?1429926030


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith, Lomita, California on Tuesday, December 22, 2015 - 09:59 am:

I can't imagine putting a reproduction manifold on my cars! A friend has a straightening fixture he made, and after you get the manifold nice and hot, the weight of the wrench alone is enough to straighten the manifold. If people wouldn't have used those silly 3-1 gaskets, they wouldn't have warped in the first place!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Tuesday, December 22, 2015 - 10:11 am:

I found early on when straightening exhaust manifolds using a straight edge and a measuring tape does not work well.

I machined discs to fit the holes in a junk block then tack welded 1/2 " pipe 16" longer then the bock to the discs set in the block.

With 8" of pipe forming a handle beyond the block you could easily check a hot exhaust manifold for straight and or distance between ports while its hot by turning the jig over to fit the manifold.

With a little thought it is easy to see how to spread ports or close the distance between them by where you heat the manifold.

The two issues I had were the hot manifold has memory. When it cools a small correction might be necessary.

The other is the threads on the manifold they are often in need of attention. Other then that manifolds have fit perfectly with standard glands.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Tuesday, December 22, 2015 - 10:27 am:

Here's what I do:

http://www.mtfca.com/discus/messages/331880/342833.html

Straight edge check after cool. Done many this way they always fit perfectly afterwards.

Not anything I could do for anyone else, it takes about an hour to set up and straighten each manifold. Add in the cost of gas and you are over the price of a new manifold if you charge anything for labor.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Tuesday, December 22, 2015 - 10:42 am:

So far I've been able to find good original manifolds and haven't had to buy a new one or straighten an old one. I did try straightening one just to see if I could do it, and I burned a hole through it. :-( My question is about the repop. Is it the 1925 and earlier version, or the 26-27 type?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Tom Carnegie Spokane, WA on Tuesday, December 22, 2015 - 11:06 am:

Paul said: "With a little thought it is easy to see how to spread ports or close the distance between them by where you heat the manifold"

I found that once a manifold was "stretched" it was very difficult (impossible?) to shrink it back down. With normal gland rings it might be possible to install all four rings, but I use close tolerance gland rings that I machine out of chrome-moly. Even a few thousandths off and they won't fit.

Larry said: "If people wouldn't have used those silly 3-1 gaskets, they wouldn't have warped in the first place!"

Yes, the 3-1 gaskets certainly exacerbate the problem, but even with my super-strong chrome-moly rings, the manifolds still warp. When I am torn down at the Montana 500, the rings are all in place, but it is usually impossible to get all 4 to fit back after the manifold has been pulled the first time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Vitko on Tuesday, December 22, 2015 - 11:52 am:

I wont argue with the best Tom! Probably should have said in my opinion! BUT! If I were in your shop with a rose bud and my equipment it would be interesting to see the results. The key is the jig with discs welded to the pipe. I doubt I could get them within one thou but the discs would not drop back into the manifold with the pipe handle aligning them within say five thou off correct alignment.

As you know 1/16" is 62 1\2 thou. Machine some discs to fit junk block ports weld a pipe handle across them with the 1/8" discs in the junk block leaving handles out each end to keep from burning fingers on the dozen or more checks of heating location.


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