stud removal
 

While in the process of replacing rusty exhaust manifold nuts guess what i did?? Yep, two studs just broke off. Lots of naughty words later i find they must have been broken for quite a time. I had soaked them for a week in plus gas and barely put any pressure on the ratchet before they just dropped out. Now of course i have the wonderful job of trying to get the remains out of the head. I really hadnt planned on removing the cylinder head but unless one of you wizards can suggest a short cut i guess thats now my only hope. I suspect a previous owner bodged it before passing the problem on to the unsuspecting fool who now owns it.

look on Youtube, there are many examples of how to remove a stuck stud

macafee2

Unless you are good at fiddly delicate things it's best left to an expert.--Normally if they are reasonably easy to get at they need to be drilled DEAD CENTER.--:eek:-Then a stud extractor carefully screwed into the drilled hole.---Now you come to the delicate bit. Stud extractors are made from high carbon steel and are very delicate.--It's VERY easy to put a bit of sideways pressure on the extractor and SNAP it.---You then end up with the doubly difficult job of removing something that is too hard to drill.---:duh:






PS. The moral of your story is------If it ain't broke, don't try to fix it.---;)

I don't know the studs, is any stud poking out of the hole or is there thread in the hole you can screw into?

Drilling dead centre, I found a neat trick on Youtube. If you have the tools its a piece of cake.

macafee2

Four solutions, some can with a bit of luck be done in situ.



1) If there is sufficient stud standing proud, weld a nut on it, the direct heat on the stud usually helps as well.


2) Flush with the head, drill and use a stud extractor, either the tapered left hand thread type or the spline type, used with care as mentioned above, but if it is well and truly rusted in it may not shift.



3) Drill out and tap to the next size up space permitting.


4) Expensive but sometimes a life saver when used by a skilled operator.......spark erosion.


To prevent a reoccurrence, use stainless or brass nuts and some high temp ceramic anti-seize compound.

thank you all for the advice. will attempt to drill and use easy out in situ, space is really limited between manifold and rad but a right angle drill adapter might just do the job if i am very careful. the you tube vids are really good as guides to doing a never attempted job. the studs i have removed either came out really easy or just snapped off ( 2 in total ) level with the head surface. I have a set of stainless replacements waiting to go in if this works. If not I will have to remove the head so I have enough room to rectify the problem. will post on progress ( or lack of knowing my luck.) chris.

If you can, try and make a drilling jig, so that you stand a fair chance of drilling and not snapping

This is for a Porsche but you get the idea.
https://www.design911shop.com/Stomsk...4aAnieEALw_wcB

https://youtu.be/2cND6gJlbsk

Linky from America showing a guide.

studs
 

these studs are extremely hard and especially brittle.i suppose that its the heat that they have to endure.even when they are new they can shear off very easily whilst tightening unless you release any other pressures on the flanges i.e. a hanging exhaust your trying to mate up. rimmers dont sell these now for the kv6 ... only when buying a new manifold complete. i had the same issue as the op has. the broken stud would not tap out or drive out in situ too much flex.... they are on splines and are driven in sometimes not aligned properly when the bolt is first tightened from new. he is correct .. no room to manoever very tight in there especially lying on your back working. i did however manage to remove 2 of them using a ball joint separator with a little improvision. would have been better with a bolt and nuts setup but there must have been a reason for this set up ... :shrug: