Broken Manifold/Crossover Stud- difficulty of replacing manifold

[Ashyukun]

So, with my usual brilliance while trying to pull the stock exhaust system to install a setup similar to Bill's, I broke one of the studs on the driver's manifold where it connects to the crossover (first pic). Looking at it though, I halfway wonder if breaking it wasn't almost a good thing as it's a BAD shape, and I would be unsurprised if I would have had a lot of trouble trying to use it for the new setup.

However, this means that regardless of exactly what I do (leaning heavily toward going all-in and getting Hervey's headers/exhaust setup, though I could just replace that one manifold- if the other side comes apart more easily) at least that manifold has to be replaced. Looking at the nuts/studs on both sides, I'd be unsurprised if they had ever been taken off- both the nuts and the studs look to be in pretty bad shape. I had already changed out of my shop clothes when I went out with the camera so the angles aren't the most ideal, but I took a few pictures.

I'm generally too far to reasonably take the car in to any of the shops that specialize in D's (closest one is about 100 miles away), but there is an exhaust place nearby that I could get the car to in the state it's in (well, the state its exhaust is in... I'd have to put the fascias back on and the seats back in :P). I'm wondering what the consensus is from those who have done this kind of thing before is on whether I'd probably be better tackling it myself, or letting the pros handle it.

I'm generally pretty fearless when it comes to doing things on the cars, but with this if I break a stud it would potentially mean having to pull the engine to replace it. Granted, a shop might have the same problem- but I'd hope they'd have the experience to not have that happen...

152415231522

[82DMC12]

Which stud broke off? That will help determine options. I can't tell from the pics.

Andy


Sent from my Droid using Tapatalk

[content22207]

Take the manifold off, then drill & tap it for a new stud or bolt (the original stud has become part of the manifold now -- just use it as part of the new threads). I've done this on a Ford.

Bill Robertson
#5939

[DMCMW Dave]

Ehh - "take the manifold off" is a pretty loaded statement likely to leave you with even more broken studs, these sticking out of the engine and even harder to get to.

If the 8 mm manifold outlet studs looked like what you show in the pictures, the 7mm engine studs won't look much better. They will break if you don't use lots of heat on the nuts, and even at that you may find some that are already broken or fall off.

Get ready for the slippery slope of exhaust work . . . .

[1batt4u]

What would be the best way to prep for this, before starting to remove bolts from the engine??

[content22207]

Don't remove the studs -- split the nuts off, clean up the threads with a die, then reinstall with stainless nuts.

Bill Robertson
#5939

[content22207]

I just noticed: the exhaust manifolds use totally opposite mounting holes side to side:
1562

Since Bob is throwing away his crossover pipe, why not simply snap off all the original studs, then remount the manifolds on the opposite sides, using new studs in the virgin holes.

This of course would not work if he wanted to reuse his crossover pipe (crossover pipe will not mate up to manifolds that have swapped sides).

Bill Robertson
#5939

[SamHill]

All this is easier said than done. Why in GOD's name did they use such small steel studs. One of the differences between this and, say, Mercedes which seems to put a little bit of thought into making things bigger and heavier. It's a good move to use the unused holes. (I hate to make this next statement, but I will. "Some of my virgin holes are now filled with new studs." Yeah yeah ha ha ha.)

If either of you guys need to look up some freelance guys on C/L and pay them by the stud, you might want to try it. Hopefully they won't warp the shit out of your metal.

[Ashyukun]

I'd think it would be a lot wiser if you could do it to split the nuts and then try and remove the existing studs to replace them with stainless ones... or at least not snap off the existing ones and put new ones in the other holes in hopes that sometime down the line when the engine is pulled that the original studs could removed more easily.

Using the other holes is an interesting idea though...

[SamHill]

I wanted to share this pic of how we managed to use an extra flange to work around a broken stud.1564

[DMCMW Dave]

Don't remove the studs -- split the nuts off, clean up the threads with a die, then reinstall with stainless nuts.


This presumes that they are not as rusted as the much larger outlet studs were. I'm not sure why they would necessarily be in any better condition. Was this a salt-belt car at some point?

[Ashyukun]

This presumes that they are not as rusted as the much larger outlet studs were. I'm not sure why they would necessarily be in any better condition. Was this a salt-belt car at some point?
It came from Dayton, so yeah. And it's not like Lexington is entirely OUT of the salt belt, either.

I'm definitely worried about the condition of the engine studs myself- that's the primary point of this thread, trying to figure out what the best approach would be- especially with regards to going forward with it myself or having a shop do it. If I were closer to one of the actual shops, I'd almost certainly take the car there and have the current exhaust pulled and new put on, but the closest (up just north of Cinci) would be over 100 miles- though I could still pretty much just put the stock muffler back on temporarily. My concern with taking it to a local exhaust shop would be that they'd snap a stud themselves and not be able to fix it... :/

[content22207]

Unless someone can come up with a good reason not to, just snap the damn things off and flip the manifolds.

Bill Robertson
#5939

[Ashyukun]

Unless someone can come up with a good reason not to, just snap the damn things off and flip the manifolds.

Bill Robertson
#5939
"I don't want to unnecessarily destroy things or potentially make like a lot harder down the line," is a good enough reason for me, at least.

If I do decide, for example, to pick up Hervey's headers, I wouldn't be able to use them if I had just snapped the studs off willy-nilly. I've tried really hard to not make any changes that cannot be reversed to put the car back to stock, and simply destroying the ability to use the stock exhaust system because it would be less work doesn't sit well with me.

[DMC5180]

"I don't want to unnecessarily destroy things or potentially make like a lot harder down the line," is a good enough reason for me, at least.

If I do decide, for example, to pick up Hervey's headers, I wouldn't be able to use them if I had just snapped the studs off willy-nilly. I've tried really hard to not make any changes that cannot be reversed to put the car back to stock, and simply destroying the ability to use the stock exhaust system because it would be less work doesn't sit well with me.

Agreed, But the likelihood of returning to stock exhaust is slim to none. You can however, pickup used manifolds for next to nothing because so many systems have been converted to headers. As for head studs, try not to snap those off. It cold make replacing them a PITA. Some will say, just put new studs in the empty locations in the head and don't bother with fixing the old ones. You know and I know that's a half-assed way to do something. Although their are those rare times when something like that is unavoidable. Always try to do a job properly before se coming it'll do repairs.

[David T]

When trying to disassemble exhaust hardware the only way to do it without breaking or cutting everything is to use an acetylene torch. It is the way all professional shops do it.You heat the nuts up to cherry red and let them cool a little. Heat up again to cherry and then turn them off easily without destroying threads. The nuts are expendable, you try to save the studs. The only real draw-back is the danger of fire and heat damage. With the proper precautions they can be controlled and/or minimized.
David Teitelbaum

[SamHill]

the less torturous way for sure.

And if you do wind up drilling, they make great trophies for your cubicle at work.

1643