Exhaust Manifold Problem

[StevenWalker]

I have an exhaust manifold problem. After changing my head gasket I went to reinstall my stock exhaust manifold. It appears that the manifold is now shorter in length. I can get the bolts in the first four holes but the last two bolt holes in the manifold do not line up with the bolt holes in the head. I have tried heating the manifold in the oven to see if the heat will cause it to expand but no luck so far. Does anyone have any ideas on what to do?
Thanks, Steve

 

[Seabee]

Buy a new manifold. They all seem to shrink with age. Hey, that sounds unfortunately familiar...............

 

[StevenWalker]

Buy a new manifold. They all seem to shrink with age. Hey, that sounds unfortunately familiar...............

I've already been pricing a new manifold. Strange to have in come off OK then shrink while sitting on the bench. Thanks for your input.
Steve

 

[dieselshadow]

It didn't shrink on your bench. That happened over the years on your engine. It's always much easier to back a bolt out of a hole(s) when slightly mis-aligned, but nowhere near as easy to reinstall them.

The 12vs were known to break off exhaust manifold bolts when the manifold shrunk enough.

 

[StevenWalker]

You are right of course. It came off a little stiff so it it shrank on the engine.
Thanks to all for your replies.
Steve

 

[NIsaacs]

If the manifold is just shrunk and not twisted/warped, you might drill the holes one size bigger.

 

[SnoKing]

Die grinder and elongate the holes. Less material removed.

 

[EricViviano]

Get a new manifold, youll thank me later. Your stock one is probably cracked anyways, inspect it.

https://www.dieselpowersource.com/2-piece

 

[BigPapa]

Manifold shrinkage is a common and well documented issue. I remember reading articles in the TDR Magazine years ago about bolts being bent, not lining up, and even breaking part of the head off. A two or three piece manifold was the standard fix. I personally have an ATS 3-piece on mine. Now, the best option seems to be one of the Stainless Steel manifolds but they’re quite a bit more than a multi-piece iron manifold.

 

[Cummins12V98]

Die grinder and elongate the holes. Less material removed.

If no cracks I would also grind to fit. It’s done shrinking and may last the life of the engine.

If it were a 12V I would replace it.

 

[Seabee]

I installed one of the stainless manifolds on mine. It works well and looks good!

 

[Joe Mc]

Did the ATS 3 piece on mine when I noticed odd looking black lightening bolt sort of looking area (crack) on mine, think it was between #4&5 or 5&6. That was around 10 or more years back. My thought on your's: If it isn't cracked (as others mentioned) it has most likely shrunk all it will, elongate holes try just the most forward hole on #1 and most rearward hole on #6 first, then try to fit those bolts in, just thread them in 2 or 3 turns, then see if and of the other holes will take a bolt. You should be able to move the manifold a bit as you try to bolt other holes. Heck you might get lucky. At least give it a try, if it works good if it doesn't then at least you gave it a shot before spending $$$ on a 2 or 3 piece. Gives you good reason to tell the wife "I tried but it didn't work out so I had to buy the XXX one". Don't be tempted to just get a stock unit, why replace with something the same as what already failed. Good luck and keep us posted.

 

[Ozymandias]

Changed my manifold four weeks ago, leaked at #6 seal, was badly shrunken, bolt almost didn't came out because of this.
Installed a 2-piece BD pulse manifold.

Dont forget to re-torque the bolts after the first hot/cold cycle.

 

[Michaelsloft]

Did the ATS 3 piece on mine when I noticed odd looking black lightening bolt sort of looking area (crack) on mine, think it was between #4&5 or 5&6. That was around 10 or more years back. My thought on your's: If it isn't cracked (as others mentioned) it has most likely shrunk all it will, elongate holes try just the most forward hole on #1 and most rearward hole on #6 first, then try to fit those bolts in, just thread them in 2 or 3 turns, then see if and of the other holes will take a bolt. You should be able to move the manifold a bit as you try to bolt other holes. Heck you might get lucky. At least give it a try, if it works good if it doesn't then at least you gave it a shot before spending $$$ on a 2 or 3 piece. Gives you good reason to tell the wife "I tried but it didn't work out so I had to buy the XXX one". Don't be tempted to just get a stock unit, why replace with something the same as what already failed. Good luck and keep us posted.

I've been considering replacing the original exhaust manifold.
Did the ATS 3-piece manifold you installed arrive assembled and aligned to mount?

 

[BigPapa]

Did the ATS 3-piece manifold you installed arrive assembled and aligned to mount?

Mine did not. I put the ends in the freezer and warmed the center. It went together easily. Came with Allen bolts. I checked them twice and they didn’t tighten either time. Been on now over 300K miles and haven’t lost a bolt yet.

 

[Ozymandias]

The BD just slips in when cold, no binding.

 

[Bob4x4]

The Ats manifolds come assembled for quite a few years now,although not all of them I have received were the right length and some had twisted as well

 

[Joe Mc]

No my 3-piece was not assembled. I made a exhaust side of the head template out of material similar to a file folder = placed the template on the head, tapped lightly with the rounded end of a ball peen at the area of the most rear bolt hole, removed the little circle that the ball peen/tapping provided, threaded a bolt in then placed the template along the side of the head, tapped the most forward bolt hole, removed circle, threaded in a bolt to hold the template (in the making) in place. Tapped the remaining holes and removed the template. After removing all the circles I taped the template on a cleaned portion of a metal workbench, using a red sharpie marker I transferred the bolt holes to the metal workbench. Heated the center section of the manifold and placed the 2 end sections in the freezer. I then placed a light coat of anti-seize on the end sections where they slide into the center. Clamped the center section onto the marked with holes portion of the metal workbench then persuaded the two ends on the center lining each up with the flat metal bench surface and red bolt holes marked upon the metal. Allowed the sections to cool/warm up to each other and the assembly when on just fine. Hope this helps. Have fun!

 

[Cummins12V98]

Two ends in freezer and center in oven. Made a template out of a flat pc if hardwood. Drilled holes to hole each section as I pushed them together. Sick as CHITZ

 

[EricViviano]

My stock manifold was cracked worse than I thought the bottom side was even worse......

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Went with 3pc DPS and stainless bolts

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