Exhaust manifold stud removal...How?

[Goose]

I managed to remove my exhaust manifold about a week ago after an epic struggle that lasted about a 2 weeks (evenings and weekends). I had to cut, grind, chisel, drill the nuts off the studs - what a nightmare!! Stupid design but enough of that because I know many others will have experienced it too.

I am now left with the original manifold which looks in good shape, and the studs, a few of which have been cut to shreds in the process of removing the nuts. I have read everything I can find on this site and others about removing studs but I thought I might ask you lot before handing it over to Geoff at Esprit Engineering.

What I have tried so far...

brute force - mole grips

shaping the stud to make it easier to get a spanner around

a gator grip socket (quite good for rusted nuts)

soaking it in WD40 (literally a small cap of WD40 taped in place around the stud etc. etc.) (also tried using Plusgas (sp?) that is supposed to be quite good.)

hammering it to 'release the threads' (suggestion of a few websites)

Cutting a line in the top of it to try and use a screw driver to twist it

What else can I try? I don't have access to any welding equipment so I can't weld a nut on to it or apply heat...

Any suggestions welcome!!

Edited July 6, 2006 by Goose

[Tony K]

Goose --

First, for any studs that are stuck in there and saveable, I would just run a die over them to clean up the threads.

Second, for penetrating oil, I would use either Twister or Kroil (are those available in the UK?)

Third, for heat I would use a handheld propane torch -- are they common there? Just a few dollars at a hardware store here.

Fourth, I'm guessing Mole Grips are like our Vise Grips? Essentially locking pliers? I have two small pairs of locking pliers -- one normal and one needle nose -- and I usually just lock the normal ones on (perpendicular to the stud, not in line) and give it a tug. If that doesn't break it loose, it will break the stud.

Fifth, if you break the stud, use progressvely larger drill bits to drill it out. Use bits made of cobalt, and lots of oil. Use a 90-degree drill for tight spaces if engine is still in car.

I hope this helps!

- Tony

[Tony K]

And make sure to use copper nuts when you reinstall it, so this is less likely to happen again!

[Goose]

And make sure to use copper nuts when you reinstall it, so this is less likely to happen again! 

<{POST_SNAPBACK}>

Cheers Tony. Good advice.

[WayneB]

Angus, I normally just intall 2 nuts onto the stud, tighten them against each other (to lock them) , and use a spanner on the lower nut to undo the stud.

If the threads too chewed, you should get yourself a stud removal tool and try that.

If that fails, there aint no substitute for an acetaline torch

This is a stud removal tool. The offset knurled wheel grips the stud as you are attempting to remove it.

Edited July 6, 2006 by WayneB

[Goose]

Angus, I normally just intall 2 nuts onto the stud, tighten them against each other (to lock them) , and use a spanner on the lower nut to undo the stud.

If the threads too chewed, you should get yourself a stud removal tool and try that.

If that fails, there aint no substitute for an acetaline torch

This is a stud removal tool. The offset knurled wheel grips the stud as you are attempting to remove it.

<{POST_SNAPBACK}>

Cheers Wayne. I will see if I can find myself a stud removal tool. (I should have guessed that there would be a specific tool for the job... )

[WayneB]

Whoops, the image got redeXed

Heres another shot of it.

I got mine from Snap-on, but Im sure the other tool manufacturers make them.

By now even the Chinese might be knocking them off (cheap)

[Richard S3T]

Use a stud removal tool, but careful use of a blow torch, aim it at the stud, not so much the head. May I suggest you don't go near it unless you've cleaned the block and surrounding area.

I am pretty sure these studs should be stainless steel. I was told that these earlier manifolds don't often fail, but the gaskets to the head do.

Copper nuts is the conventional wisdom for normal engine manifold nuts, but the joint between the head and manifold on these engines puts up with a lot of movement through expansion and contaction. The relatively thick gaskets puts up with this (you used to be able to get thicker ones), but only if you don't crush the gasket and allow movement by sticking with the correct torque settings. I think the correct nut material is again, stainless steel. I was recommended to use Aero tight nuts as they will not slacken off so easily. With some manifolds you need special A/F nuts for clearance, but where possible it is best to fettle the manifold to accept standard A/F nuts so that you can stick with Aerotight type. The final recommendation would be to use the locktab set from later engines.

Best of Luck

- Richard

[GSimpson]

You can get cheap knock offs as mine didn't cost very much

Graeme

[madmezza]

Not so much advice (yet), but my car is going to Geoff's today for him to have a look at the exhaust which is leaking somewhere (I feel like I've got a 50cc motorbike from the sound of the engine!).

Anyway, he may have to remove the manifold to sort this out and it hasn't been done for at least 8 years (maybe 18 years!). If you give him a call later in the week he's likely to have very recent experience with the problem!!

Rich