myeates
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| posted on 8/12/06 at 01:14 PM |
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broken exhaust stud
hi all i managed to break one of the exhaust studs last weekend anyone any tips on getting out. it has broken below the surface of the hole, i have
some easy outs but not really sure about them will i be ok just drilling a normal hole down the stud.
thanks guys
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flak monkey
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| posted on 8/12/06 at 01:20 PM |
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If you have a welder, weld something onto the end of the broken stud.
Just bear in mind that if you break a stud extractor off in the stud you will never drill it out.
The other way is to carefully centre punch the end of the stud and drill the old one out. They are M8, so the tapping drill would be 6.8mm. Go for a
6.5mm drill and pick out whats left of the old stud. You need to make sure you drill on the centre of the old one tho.
David
Sera
http://www.motosera.com
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3GEComponents
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| posted on 8/12/06 at 01:34 PM |
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"You need to make sure you drill on the centre of the old one tho."
That's easier said than done 
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02GF74
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| posted on 8/12/06 at 02:44 PM |
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do a quick search, some one not so long ago had the same problem.,
general consensus is the easy-outs don't work and are more likley to snap making it even hard to extract.
carefull trilling + heat (but not so much the amniold cracks  ); or even get a s/h one?
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myeates
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| posted on 8/12/06 at 03:05 PM |
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the studs are actually 5/16 unc so what would i need to drill the thing out. there is not enough stud sticking out of the flange to weld nut on
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David Jenkins
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| posted on 8/12/06 at 03:56 PM |
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If you're not happy about drilling the stud out, take the head to an engineering shop - they can use a spark eroder to remove the bulk of it.
It's an easy job and the machine can be left to its own devices while it's working - shouldn't cost too much (maybe just a tenner in
the coffee fund). It's also an accurate process, no matter what shape the end of the stud may be.
David
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DarrenW
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| posted on 8/12/06 at 04:27 PM |
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Ive seen old timers in a toolroom remove broken studs in expensive tools. Im sure they try and carefully grind the end flat before centre drilling and
then drilling out.
Take your time. Centre drills can give you a good start. Easy does it with the drill. You dont want it to wander or snap. I take it engine is in car
and you dont want to remove head.
Zeus book says 5/16 UNC tapping drill is 6.6mm, clearance 8mm. sanity check that first against good stud or tap.
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myeates
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| posted on 8/12/06 at 04:56 PM |
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yep all in everything on engine apart from exhaust dont want to take the thing out or remove anything for one stud. will try with an easy out first
after heat but will just face the music if i break that then if not will just drill and pick out remains thanks guys
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MikeRJ
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| posted on 8/12/06 at 05:12 PM |
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quote:
Originally posted by flak monkey
If you have a welder, weld something onto the end of the broken stud.
That works brilliantly if some of the stud is protuding, but as it's broken below the surface of the hole you just risk welding the stud the
stud to the surrounding metal and making things worse.
Drilling it out is really the only practical solution, but can be tricky due to exhaust studs being very hard. However I recently managed it on a
crossflow head with just a normal hand held electric drill and the threads were ok afterwards.
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BenB
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| posted on 8/12/06 at 05:15 PM |
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Drill it out...
Stud extractors / easyouts snap (I know from bitter experience- snapped one trying to get a sheared bolt out of my way expensive and getting rarer
renovated calipers!!!)
Just start small in the centre of the stud (dremel with a die grinder can be helpful to make a hollow in the middle of the stud in which to
drill)....
Slowly use bigger bits then before the drill gets big enough to damage the thread use a mini screwdriver to collapse the thin tube of stud thats left
into the middle of the hole and pull out...
Suprisingly easy...
Once I'd drilled out the stud extractor, the bolt itself was easy work...
After all, you have to drill a reasonably big hole for the bloody stud extractor. Why not just do the job properly and use another 2-3 bits rather
than risk shagging it all up by shearing the extractor doodah....
Ben
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Catpuss
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| posted on 8/12/06 at 06:21 PM |
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I found welding was a waste of time.
Drilling fooked up the head too.
I hammered in a bit to drive it out and the bit broke.
In the end I used a leather working awl and poked out what I could.
Oh, then got a new head 
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myeates
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| posted on 8/12/06 at 07:28 PM |
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by what people have said i think i will just drill it out as these extractors are hard and will probably wreck all the drill bits. these things tend
to happen with me.
Benb did you heat it up prior to picking it out
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thunderace
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| posted on 8/12/06 at 07:32 PM |
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an old Rolls Royce machanic showed me a trick give it a few hits with a hammer heat it let it cool dowh and hit it again then try chaping it round
with a punch it has never failed to work for me (i have never got me easy outs out there packet or my zecorum drill set)
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Mark Allanson
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| posted on 8/12/06 at 10:20 PM |
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Get a 4mm left hand drill, the stud will usually react to the drilling heat and the friction (turning the right way to undo) and wind itself out
before you have gone in 2mm
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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zetec7
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| posted on 9/12/06 at 03:43 AM |
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If you want to use an extractor, get the kind that are square in cross-section and tapered...they are not hardened, but rather spring-tempered, and
MUCH less likely to snap. Actually, they'll start to noticeably twist first, so you'll have plenty of notice if you're overdoing
things. A fair bit of heat helps, too. I've had great success with these (but I've had the other kind - the ones that look like coarse
screws - break off EVERY time I've tried to use them!)
http://www.freewebs.com/zetec7/
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myeates
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| posted on 9/12/06 at 10:17 AM |
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any one know where i can get left hand drill bits from then as may be an idea for the future
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rusty nuts
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| posted on 9/12/06 at 01:30 PM |
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Should be able to get left hand drill bit/extractors from any decent tool or engineering suppliers
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02GF74
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| posted on 9/12/06 at 01:44 PM |
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quote:
Originally posted by thunderace
an old Rolls Royce machanic showed me a trick give it a few hits with a hammer heat it let it cool dowh and hit it again then try chaping it round
with a punch it has never failed to work for me (i have never got me easy outs out there packet or my zecorum drill set)
are those powered by your flux capacitor?
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myeates
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| posted on 10/12/06 at 06:33 PM |
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its out thanks guys in the end just drill and picked then used one of the old studs to screw in and wind the rest out
o and chucked the extractors in the bin to stop temptation
now got to await the next problem 
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Catpuss
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| posted on 11/12/06 at 07:49 PM |
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quote:
Originally posted by myeates
its out thanks guys in the end just drill and picked then used one of the old studs to screw in and wind the rest out
o and chucked the extractors in the bin to stop temptation
now got to await the next problem
Lucky you . When I finally drilled in the drill went straight down the middle and gouged out a bit of the head bolt behind it.
Fooking pain the arse that fiasco was.
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