Sheared Exhaust Stud in Cylinder Head

[mdouglas]

Julian

I'm in Surbiton (which can't be all that far from you) and have the following that might help:



They taper internally and are designed to really bite into a stud or rounded off bolt head.

I also have a range of small scale pipe wrench/stilson type devices that are designed to get tighter the harder you pull on them. They saved my bacon when removing a corroded exhasut stud from a Suffolk Colt petrol lawnmower that I was servicing.

More than happy to drop some stuff off for you to try. I'm commuting up to Luton just now and travelling the South Circ and North Circular to pick up the M1. Don't know if that brings me near your abode but guess it can't be too far given your "W London" location.

If a push comes to a shove, I also have a 150Amp MIG welder - we could weld a nut on the old stud so that you can use conventional spanners/sockets.

Let me know if I can help.

Mark

[Jason M]

Mark - those things look most excellent - what are they known as and where did you get them - same with the stilsons - all good to have in the cabinet

Julian - when you heat the area up, I presume you're concentrating the heat on the cylinder area rather than the bolt - I'm not an physisist but I had to get some bastard little bolts out the lower yolk clamp at the w/e and found that heating the area around the bolt rather than the bolt itself gave better results (ie it worked against it didn't work!) - maybe it's to do with the area around the bolt expanding more than the bolt itself cos it's hotter.

[julian]

Mark - yes please.
They look very useful. Boxadog kindly loaned me an extractor the size of a spark plug socket but it's too wide to fit into the manifold recess - tehse ones look smaller.

My one concern is that any large turning force of the stud is likely to shear it again. On the other hand it was 'necked' bu a couple of mm at the point where it sheared due to the manifold rubbing against it, so maybe the remaining stud is stronger overall.

I've pm'd you my number and can come and meet you - I'm a mile from the north circular either at Ealing common or the Chiswick Roundabout, or even the Ace.

Julian

[julian]

Mark - those things look most excellent - what are they known as and where did you get them - same with the stilsons - all good to have in the cabinet

Julian - when you heat the area up, I presume you're concentrating the heat on the cylinder area rather than the bolt - I'm not an physisist but I had to get some bastard little bolts out the lower yolk clamp at the w/e and found that heating the area around the bolt rather than the bolt itself gave better results (ie it worked against it didn't work!) - maybe it's to do with the area around the bolt expanding more than the bolt itself cos it's hotter.

I've heated round the stud area with a gas blow torch.
I really need a leccy air gun cos is doesn't seem to direct much heat to any one point.

[adamski49]

I've heated round the stud area with a gas blow torch.

Julian

Are you going for the hatrick to fully exploit the TPFT?

Adam

[Archie]

Julian

I had a good look last night, but can't find the brackets. Looks like it might be the sick squid option. To fit mine I had to bend one connector, and it didn't feel like it weakened it substantially. You might be OK without them.

Cheers

Alan

[julian]

I've heated round the stud area with a gas blow torch.

Julian

Are you going for the hatrick to fully exploit the TPFT?

Adam

Done that when two of the MZs were set on fire one night

[julian]

Julian

I had a good look last night, but can't find the brackets. Looks like it might be the sick squid option. To fit mine I had to bend one connector, and it didn't feel like it weakened it substantially. You might be OK without them.

Cheers

Alan

Thanks Alan

I will buy those brackets or make something. I've broken enough already this week

[mdouglas]

I got those during a pilgramage to the tool department of a large Sears store in the US. They are "Craftsman" brand, made in the USA!
If you've never been before, next time you're in the US, go pay a visit to a large Sears. Their toold department puts Halfords, B&Q and all the UK sh1te to shame. Over the years I've brought back timing lights, torque wrenches etc. Had some interesting discussions with security staff when they discover a 25 piece set of "wrenches" in my hand luggage!

Julian: I removed the nut from the Rockster's exhaust manifold stud this morning and tested the smallest extractor for size. It fitted a treat. I was getting it to bite with only 9mm or so of stud showing through.

I packed them, along with some stilsons etc in my bag and they're sitting under the desk in a Luton office as I type. Will give you a call to arrange a day/time/location for handover.

Mark

[Jason M]

I got those during a pilgramage to the tool department of a large Sears store in the US. They are "Craftsman" brand, made in the USA!
If you've never been before, next time you're in the US, go pay a visit to a large Sears. Their toold department puts Halfords, B&Q and all the UK sh1te to shame. Over the years I've brought back timing lights, torque wrenches etc. Had some interesting discussions with security staff when they discover a 25 piece set of "wrenches" in my hand luggage!

Julian: I removed the nut from the Rockster's exhaust manifold stud this morning and tested the smallest extractor for size. It fitted a treat. I was getting it to bite with only 9mm or so of stud showing through.

I packed them, along with some stilsons etc in my bag and they're sitting under the desk in a Luton office as I type. Will give you a call to arrange a day/time/location for handover.

Mark

Next time I'm over there then.... I got a load of spanners last time but this time it's the sockets. In the mean time I might try and get some sent from here

[sandbar]

This will not help Julian in the slightest, but I thought that I would pass on a tip that I was given and it worked for me when I anticipated a similar problem.

Sometime ago I was working on a neglected 99 50K miler. By the time I got round to the headers, virtually every nut, bolt and screw had given serious aggravation. I could see the same problem as Julian has experienced looming, so I sought advice. This is it:

Drill a small hole in the top part of the dome on the end of the chromed nut. Use the hole to fill the small space inside the nut with 'Plus-Gas' - leave overnight and - Bingo!!

All 4 nuts came off without any problem whatsoever. In fact for the second side I drilled two holes because it made putting the Plus-Gas in a lot easier, and as new nuts were needed, it did not matter how many holes were there. By the way Plus-Gas is a lot better than WD 40 for dealing with rust and corrosion situations.

Who did I get the advice from - a specialist motor bike enginers? No - a blacksmith!!

I hope nobody needs to use this advice.

Sandbar

[julian]

Sandbar

That's a good idea. Did you manage to get the studs out of the head?
I'm persevering with the Plus Gas but not sure if it defies gravity.

Apart from the nut being corroded onto the stud, the manifold flange had worn the stud to a depth of 0.5mm beyond the thread thus weakening it.

Julian

[sandbar]

In that case I did not need to get the studs out of the head. I was only trying to get the exhausts off.

No unfortunately the Plus Gas, like us all, can't defy gravity. It is just that the space inside the domed nut allows the Plus Gas to stay there and over time soak into the s**t and corrosion.

Once the nuts were off and the exhausts removed the studs were pretty corroded (horrible looking threads, reduced diameter etc.). When I was ready to reassemble I just used new nuts onto the old studs and a little Coppaslip and was able to torque up the new nuts to the correct value + 20% to check that they were not near their limit, before reducing to the correct value.

All that is of no use to you in your predicament. If I was in your situation, once I had exhausted all the things you are trying, I would get rid of all the stud that is not inside the head - leaving as near as possible a flush surface. Then make sure that you have a top quality centre punch, a top quality variable speed drill and a selection of quality drill bits of varying sizes up to nearly the diameter of the stud. Then if you are not used to doing this kind of job, then ask somebody who is and drill it out. Then use a good quality tap set designed to be used on blind holes.

I am sorry of that sounds like preaching but that is exactly as it has just been told to me by - the blacksmith!! Cos I asked him about 30 mins ago.

If it works it will save you taking the head off.

Good luck

Nigel
'Sandbar'

[julian]

Thanks Sandbar
Boxadog has offered to help as described above.
Will keep you all posted

Julian

[BockingBandit]

Bollocks. ... I've just done exactly the same thing this morning. Sheared the top right exhaust stud flush with the exhaust clamp. Deep joy,.. I feel a weekend of swearing comming on. In the end Guys... were the @Mole grips' the best soultion? Geoff