Agreed. Just because you could do it yourself doesn't mean you always should. Sometimes it just makes more sense to pay the pro to do it instead of experimenting.
Repairing damaged manifold stud and smoothing surface
- Thread starter JHZR2
- Start date
SammyChevelleTypeS3
$50 site donor 2023
Also seizes to near impossible to separate. Really surprised to see s/s installed in cast metal or other material unless it was done by an Indy shop at some point or maybe as a Diyer job at home. Sure , no rust but never good if one plans to separate or take apart again years later.
I second this (electrical discharge machining).
All depends on what stainless it is, stainless can gall real easy too.
In this case edm won't do anything special a drill and boring end mill can't do.
It just won't happen on a drill press.
In this case edm won't do anything special a drill and boring end mill can't do.
It just won't happen on a drill press.
This is a long shot, and it sounds as though you have other good options, but I wonder whether you could thread a deep nut onto the stud, leaving enough female threads to be able to then thread in a hollow drill guide.
You could then accurately drill out the centre of the stud, and then hopefully the stud could be removed with a LH drill bit.
You could then accurately drill out the centre of the stud, and then hopefully the stud could be removed with a LH drill bit.
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LOVE the drill guides. Can those be purchased, or are they custom made?
I've got a set of drill guide bushings I made for Windsor water pumps
But, they can be purchased. Or anyone with a lathe can center drill a bolt.
OP already has it on the bench. Anyone with a mill or a drill press and a good eye can make this painless.
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I've seen guide bushings - but not bolts that could be used directly on the stud if there's threads left.I've got a set of drill guide bushings I made for Windsor water pumps
But, they can be purchased. Or anyone with a lathe can center drill a bolt.
OP already has it on the bench. Anyone with a mill or a drill press and a good eye can make this painless.
Drilling a bolt freehand is a talent that few have, it's like like drawing a straight line freehand.
I've known people with the knack, but not many.
This is most definitely a solvable problem.
THe best method is center drilling, as others have indicated.
Heating the stud doesn't really work; you really need to heat the manifold, not the stud.
The stud is already ruined, so the main thing is just not hurting the manifold. Put your chaser or other harder nut on the stud, put a socket over it, and hit it with a bolt breaker with a good, hard-hitting air hammer.
I've never had the bolt breaker+heat method fail. Vibration is the most effective and reliable rust-break I've found.
THe best method is center drilling, as others have indicated.
Heating the stud doesn't really work; you really need to heat the manifold, not the stud.
The stud is already ruined, so the main thing is just not hurting the manifold. Put your chaser or other harder nut on the stud, put a socket over it, and hit it with a bolt breaker with a good, hard-hitting air hammer.
I've never had the bolt breaker+heat method fail. Vibration is the most effective and reliable rust-break I've found.
JHZR2
Staff member
I made my own.
I know I had a slight leak in my 1991 MB 300D. I could smell it when stopped, and my smoke machine confirmed it.
I took some time off today to remove the turbo and manifold. It was an ok job other than a few lousy bolt locations and a tight space.
Cylinder number five was all sooted up. This is where I had found the leak.
I thought there was mild seepage from the turbo gasket. I saw some signs of that too.
All the exhaust bolts were loose, or I should say, came out easily. One snapped, or was broken already. It was on the...
I took some time off today to remove the turbo and manifold. It was an ok job other than a few lousy bolt locations and a tight space.
Cylinder number five was all sooted up. This is where I had found the leak.
I thought there was mild seepage from the turbo gasket. I saw some signs of that too.
All the exhaust bolts were loose, or I should say, came out easily. One snapped, or was broken already. It was on the...
Did so because I was in a pinch. Found them cheap on Amazon or eBay after that…
Yeah. My hope was that heating the stud would have helped break the bond and also pump enough heat into the manifold to expand it a bit.
Of course the turbo flange is angled so drilling through could be a bit risky. I’d probably cut it to just a thread or two and then use a nut as a guide to ensure centering.
Theres no nut seized on. But hammering the stud directly is probably fine at this point.
Thing is if I could chase the threads with a die, and get them reasonably functionally, perhaps my best bet to avoid issues and another six months of sitting with no time is to just try to sand it flat between the studs and rely on a compliant gasket and some copper gasket coat to cover the irregularities.
JHZR2
Staff member
Closing out this thread and going back to the broken stud removal thread. I got two out with mapp gas and the back and forth motion using my Hazet tool.
One broke below the surface, the other broke above. I kind of wish both had broken below the surface. The one then some above surface is in a blind hole.
This thread was good for a time when I thought I was going to reuse studs. I’m not. So I’d ask that the thread continue on the other one.
When the time comes to resurface I may re-open this.
One broke below the surface, the other broke above. I kind of wish both had broken below the surface. The one then some above surface is in a blind hole.
This thread was good for a time when I thought I was going to reuse studs. I’m not. So I’d ask that the thread continue on the other one.
When the time comes to resurface I may re-open this.
JHZR2
Staff member
I am reopening this thread because this is the one about resurfacing.
The other thread linked above had my trials and tribulations trying to get the stainless steel stud out of the cast iron manifold. It was quite difficult. But I got there and I began to work on resurfacing. I managed to find a very cheap used 6 x 48“ belt sander originally I was thinking to try to do it myself on a piece of plate glass. It never would’ve worked. I’ve spent a lot of time using 160 grit sandpaper on this machine and it still is very very challenging.
I started with the turbo flange side. It was smaller, but the erosion was deep, this was one of the main spots where I’ve seen leakage. The leakage on the actual manifold to block was less.
I worked the turbo side manifold until it got quite smooth and clean, and I verified flatness with a straight edge along the way
Eventually after more work, I got it to this:
And finally this:
And then to the point where the low section was barely a few visible pockmarks.
I bought empire abrasives sanding belts, including finer grit that I’ll do the finishing touches for this with. @Trav recommended their products. But I want to do the dirty initial work with the belt that came on the machine as I bought it. It was used (not much).
Next I move on to the actual head side, where there is some warping.
SammyChevelleTypeS3
$50 site donor 2023
Looking good. Very nice. Even with the slight metal loss , erosion on the outside of one. I have stopped similar problem leaks like that.
I got creative a few times in the past. For the times I could not spend much money having machine shops resurface flanges. For those I put some graphite gasket material tape on the flange faces or the gaskets. The thicker graphite helped filled in the eroded spots and never had further leak issues. Of course I would never do this to anything high pressure or with any dangerous substance equipment.
JHZR2
Staff member
I started working the long five cylinder side.
I knew from when I took it off that there was some irregularity to the surface. If I put it on a flat surface in the center, both ends are raised off the surface by let’s call it 1/16” maybe a bit less.
This is how it looked when I pulled it on the flange side. Sanded down photo is above in a post a few back.
For the head side:
I’ve started to sand it down too. But the high point doesn’t seem to go down relative to the rest, even when only working the center area.
I knew from when I took it off that there was some irregularity to the surface. If I put it on a flat surface in the center, both ends are raised off the surface by let’s call it 1/16” maybe a bit less.
This is how it looked when I pulled it on the flange side. Sanded down photo is above in a post a few back.
For the head side:
I’ve started to sand it down too. But the high point doesn’t seem to go down relative to the rest, even when only working the center area.
JHZR2
Staff member
Final results tonight.
There but not quite. The two cylinders on the ends, #1 and #5 are higher off the plane than the center. But sanding only the center doesn’t seem to help much.
But most of the corrosion around the holes is taken off.
How much material removal is enough? How perfect does it need to be in terms of surface and variation from center to end?
I also got some copper spray intended for these kinds of uses to help hopefully manage some irregularities, I’d spray it on the manifold side to the gasket. The gasket to aluminum head I won’t spray it to avoid dissimilar metals.
At least that’s my thought for this weekend.
There but not quite. The two cylinders on the ends, #1 and #5 are higher off the plane than the center. But sanding only the center doesn’t seem to help much.
But most of the corrosion around the holes is taken off.
How much material removal is enough? How perfect does it need to be in terms of surface and variation from center to end?
I also got some copper spray intended for these kinds of uses to help hopefully manage some irregularities, I’d spray it on the manifold side to the gasket. The gasket to aluminum head I won’t spray it to avoid dissimilar metals.
At least that’s my thought for this weekend.
SammyChevelleTypeS3
$50 site donor 2023
With the amounts of heat and stress from the heating and cooling cycles those manifolds endure , it is most likely a small bit warped as you are seeing indications of. Warps in those high temp applications can be pretty tough to seal 100% leak free once you develop one.
As hot as it is these days and depending on how much work you are or not up to...... I would really consider having a local machine shop give you an estimate (should not be much) to refinish the face. Doing it that way if affordable , you then have a much better chance of a leak free future not having to deal with it again.
As hot as it is these days and depending on how much work you are or not up to...... I would really consider having a local machine shop give you an estimate (should not be much) to refinish the face. Doing it that way if affordable , you then have a much better chance of a leak free future not having to deal with it again.
JHZR2
Staff member
If I knew of one I would.
Doing this is likely to become a many hours ordeal to find a place, get the part to them, get it back, etc.
Which is why 15 mins here and there has been preferable.
But your point is taken, and I appreciate it!
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From what I understand once a cast iron part has aged and warped, after you machine it flat again it's better than a new part.
JHZR2
Staff member
The key is to get it flat!
