Removing Exhaust manifold studs - tips wanted please

[Tedswagon]

I removed the first half of the exhaust manifold on my M50 lump. As you know there are 12 threaded studs and nuts on each manifold. Of the 12, 9 nuts and studs came out relatively easily the remaining three nuts came off leaving the studs still in the head. The thread looks good but a little rusty. I would prefer replace all of them with new studs and nuts.

Do any of you have tips for removal of the 3 remaining studs?

I do not have access to welding equipment so welding the nuts back on is not an option. I am thinking, if I put the nuts back on and damage the thread then maybe that would work but I do not what to do that if there is a better way to try first. i would rather avoid drilling and re-tapping the holes.

Any tips

[gromgsxr]

if the studs are still intact put 2 nuts a stud and lock them together then use the bottom nut to unscrew the stud, heating the the area up will help to.

[Brianmoooore]

if the studs are still intact put 2 nuts a stud and lock them together then use the bottom nut to unscrew the stud, heating the the area up will help to.

This is the 'standard' method of removing studs, but whatever you do, don't shear them off, although M5x head studs usually come out without much effort.

[steve_k]

if the studs are still intact put 2 nuts a stud and lock them together then use the bottom nut to unscrew the stud, heating the the area up will help to.

^^^^^^^^^^^^^^this, but make sure you soak them with the likes of wd40 for a day or two before hand.

Also, I would replace the studs with new ones, you can find them cheap enough on eBay.

[Tedswagon]

Cheers folks. That sounds like a perfect plan. Already soaking.

[steve_k]

if you use the "double nut" method it helps if you have a split ring/brake pipe joiner spanner as it spreads the load evenly round the nut.

[Brianmoooore]

if you use the "double nut" method it helps if you have a split ring/brake pipe joiner spanner as it spreads the load evenly round the nut.

FAR too slow, if you have several to do. Ratchet ring spanner on before the second nut is added is the way to go.

[steve_k]

if you use the "double nut" method it helps if you have a split ring/brake pipe joiner spanner as it spreads the load evenly round the nut.

FAR too slow, if you have several to do. Ratchet ring spanner on before the second nut is added is the way to go.

forgot about those

[reggid]

wd40 and the like is crap, the best stuff is 50/50 acetone and ATF, its well proven to be much much better

[steve_k]

wd40 and the like is crap, the best stuff is 50/50 acetone and ATF, its well proven to be much much better

true but if thats all you have to hand then it's make do.

[Speedtouch]

Indeed, or PlusGas penetrating fluid.

[steve_k]

like i said earlier, it also makes sense to replace the old studs with new ones & run a tap down the threads to clean them out before installing the new one's.

[Tedswagon]

like i said earlier, it also makes sense to replace the old studs with new ones & run a tap down the threads to clean them out before installing the new one's.

Good advice, I hadn't thought of that. Will get a tap kit.

[steve_k]

like i said earlier, it also makes sense to replace the old studs with new ones & run a tap down the threads to clean them out before installing the new one's.

Good advice, I hadn't thought of that. Will get a tap kit.

R ry & find a metric & imperial kit just to be on the safe side.

[DanThe]

Ive got a box of new M7 bolts if you want to buy enough to do yours? I had to buy a box of 100 to do what I needed, screw the bolt in, cut the head off x24

[steve_k]

Ive got a box of new M7 bolts if you want to buy enough to do yours? I had to buy a box of 100 to do what I needed, screw the bolt in, cut the head off x24

or just do what i did when i replaced the manifold studs on my m20,

1m high tensile steel threaded bar cut to length

[DanThe]

M50 studs are M7x1 thread so it doesn't come in many varieties, hence I had to buy 100

[steve_k]

M50 studs are M7x1 thread so it doesn't come in many varieties, hence I had to buy 100

true it can be difficult (but not impossible) to find.

you've always got a ready supply of M7 studs/bolts if needed

[Topblag]

I'm heading past yours on Thursday night probably, can drop a tap and die set in if that'll help.

[Yeti]

get a blow torch on the studs and double nut it and remove.the best way i have found.i did it to a 30 year old e30 and took all of them out. worked a treat

[Tedswagon]

Sorry not been back to you - was away with work most of the week.

Pulled them all out with little problem using the two nuts method!! Kinda sounds wrong - use the two nuts method!! It was like when my wife asked me where I was going when I left the house the other night and i said i was off to the garage to soak my nuts in WD-40.

Thanks Dan but I'll just order a stud set I think - cutting the heads off bolts - how do you do that without damage to threads - getting nuts on and off again. You end up having to re-thread?

Cheers Topblag - when ever you are passing - call in, not seen you for ages.

[DanThe]

Screw a nut onto the bolt before fitting it, cut the head off then remove the nut

[martauto]

This is fascinating stuff, listening to non engineers coming up with very credible solutions, I learn stuff each day!!!
Keep it going


Mart.