Hemi Exhaust Manifold New Design?

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HEMIMANN

HEMIMANN

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Get the old manifolds back,lay a straight edge across them,if they're bad,buy yourself a decent sized belt sander and go to work on them with 50 grit,then finish them up with 80 grit,and throw them in storage for when the "new design" breaks,lol

I hear ya - those years are behind me, though.
 

Wild one

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I hear ya - those years are behind me, though.
Hell you aren't much older then me,take your time and split it up into a few evenings after supper,when you're doing nothing but watching TV,lol
 
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HEMIMANN

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Well.....today didn't turn out like I thought.

So, amidst all the hubub in the exhaust shop, the technician understood to replace my exhaust manifolds because the bolts had broken - not preemptively prior to breaking.

The Tech inspected and removed the manifolds, nothing broken, no leaking, no damage, very clean. So he put everything back together and left the pickup call for the end of the day.

I went to the shop and said hey, I wanted preemptive replace, and the Supe said they really don't recommend it with my pristine condition (47,707 miles).

At that point I kinda threw in the towel, being tired from working outside most of the day and took the truck home.

Can't get a straight story from anybody these days. I want off the planet.
 

turkeybird56

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Well.....today didn't turn out like I thought.

So, amidst all the hubub in the exhaust shop, the technician understood to replace my exhaust manifolds because the bolts had broken - not preemptively prior to breaking.

The Tech inspected and removed the manifolds, nothing broken, no leaking, no damage, very clean. So he put everything back together and left the pickup call for the end of the day.

I went to the shop and said hey, I wanted preemptive replace, and the Supe said they really don't recommend it with my pristine condition (47,707 miles).

At that point I kinda threw in the towel, being tired from working outside most of the day and took the truck home.

Can't get a straight story from anybody these days. I want off the planet.
Maybe U can rent a seat on Blue Origin and tell em U wish to take a walk outside, LOL.

At least truck fixed ok, dat's a Plus.
 

turkeybird56

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Quite the opposite, yet related...when ya only got 12 weeks of habitable weather, you squeeze all 52 weeks into it. Hence many injuries.
OK, I got you covered. Go and Google: Red Man Suit, Wear that during your 12 weeks of outside adventures, keep U safe... :33::Big Laugh:

DA BOIRD


rm suit.JPGsad sad turkey.jpg
 
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HEMIMANN

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Could just replace the hardware preemptively with arp stuff and remflex gaskets.

Not sure that would hold warped cast iron - the bolts aren't designed for clamp loads from permanently bent metal from the original position.
 

Black1500Ram

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Not sure that would hold warped cast iron - the bolts aren't designed for clamp loads from permanently bent metal from the original position.
Agreed but didn’t you say yours are in pristine condition? I’ve seen a few threads on here of people just replacing the bolts and gaskets and calling it a day (with warped headers).

I know not the ideal solution.
 
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HEMIMANN

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Agreed but didn’t you say yours are in pristine condition? I’ve seen a few threads on here of people just replacing the bolts and gaskets and calling it a day (with warped headers).

I know not the ideal solution.

Yes. Swapping fasteners doesn't change the clamp loading. Bent manifolds do. At one time I was expert at cyclic bolted joint design at Cummins. Joints are designed for small thermal deflection. If the part warps and the bolt didn't break, i.e. if the bolt takes higher stress than the part, the part will break instead.

The manifold must be designed for acceptable small thermal deflection, and these were not.
 
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HEMIMANN

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The shop uses Remflex and ARP routinely. Another indication of quality work. I'm just miffed about the whole thing, including the failure mode itself. If I was younger and in better shape, I'd pull 'em myself.
 

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The updated manifold design uses extra braces across the top and bottom bolts. for the most part bolts don‘t break anymore but now the manifolds crack. so it’s fixed one problem but created another.
 
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The updated manifold design uses extra braces across the top and bottom bolts. for the most part bolts don‘t break anymore but now the manifolds crack. so it’s fixed one problem but created another.

Thanks so much for weighing in, @Tach_tech ! If fact, the exhaust shop mentioned that Gen V Ram manifolds were cracking!

Just goes to show that there was insufficient finite element computer modeling done on the manifold for the thermal cyclic stresses involved. I'd be demoted or fired for that kind of insufficient design! There is insufficient material to distribute the stress within the manifold itself so a stress raiser is not created.

Oh, well - thanks again. Still not installing long tube headers, since there are none with EPA cats and they cost too damn much, esp with inflation (were $1,800 now $2,200)
 

Black1500Ram

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Thanks so much for weighing in, @Tach_tech ! If fact, the exhaust shop mentioned that Gen V Ram manifolds were cracking!

Just goes to show that there was insufficient finite element computer modeling done on the manifold for the thermal cyclic stresses involved. I'd be demoted or fired for that kind of insufficient design! There is insufficient material to distribute the stress within the manifold itself so a stress raiser is not created.

Oh, well - thanks again. Still not installing long tube headers, since there are none with EPA cats and they cost too damn much, esp with inflation (were $1,800 now $2,200)
You could look out for some used shorties there are some deals to be had.
 
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