Removing Stainless head studs

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I am in need of removing some stainless steel exhaust manifold studs from my Ford V10 aluminum head.  Several are broken below the surface and some stick out about 1/4 to 1/2 inch above the surface. These are metric 8x1.25 and are threaded in the head about 3/4 to 1 inch deep.  I am mainly concerned with the ones sticking out since they are prone to twist off flush with the head surface or below like the others.For the ones sticking out I was wondering if/how you might heat it with a torch to try and loosen it before trying to twist it out with a vice grips.  I have a MAPP right now. Have been wanting to get the Smith MD propane if that would help with this job.  I'd like to get these out without breaking off if possible.I have read about the mg600 rod and welding on a nut but waned to try just heat first.  Would heat on the stud help in this case?  If so which gas?
Reply:Heat is uselsess.  I have done a few of these.  Drill dead center, get rid of the stud and install a helicoil.ford heads suck.Davidyeah, I'm a ford man, but as a mechanic.........Real world weldin.  When I grow up I want to be a tig weldor.
Reply:The worst PITA design ever, those studs are so small I would'nt use them on a lawn mower. You might need a few extra long drill bits to get to the back ones.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:Use a hammer and small diameter drift to tap on the suds as though you were driving a nail. this with some penetrating oil is your best bet at loosening them so that you can screw them out. Be patient and allow the penetrant to work for you. I work on import cars and nissan V6s have those small 8mm studs that are always a problem. I'd say I have 15% success at getting them to back out. the others just get drilled, tapped and helicoiled.Don't talk about it, Just do it!
Reply:Yeah, Just like Vicoor said, that´s one trick that a mechanic showed me to remove rusted/old bolts. Just hit them with a hammer and a solid bar. We took 4 days and broke 3 bolts, and capped 3 more when opening a motorcycle transmission. Using this technique we would take them all without a problems and dissmantle it in 15 mins (of course another one that was in worse conditions).My Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:Thanks for the replies.  I did get three studs out today.  I twisted off another one and two are left protruding from the head.  They are so corroded they won't budge.  I'll try the hammer and punch trick.I still have the twisted off flush ones to deal with after these.
Reply:Try the "improved" hammer and punch trick. Use an air chisel with a flat bit.Don't make a rivet out of it, but gently rattle on the stuck bolt.
Reply:Originally Posted by denrepTry the "improved" hammer and punch trick. Use an air chisel with a flat bit.Don't make a rivet out of it, but gently rattle on the stuck bolt.
Reply:I have used Utetic 680 rod to build up the stud till you can weld a nut to it and use a small impact wrench on "light" to rattle the penetrating oil in, or an air chisel can help.  Again LIGHTLY.  The 680 is strong stuff and expen$ive, but I have used it for many years.  If you do it right, the bolt may snap off deeper in the hole, so just do it again.  The rod has a nice slag that makes it "easy"  to weld up the stud and not to the hole.  Weld a little on the stud, let it cool, weld a LITTLE more, let it cool till you got a tit big enough sticking out to put an nut on and weld the nut to that.  I don't know if 680 is still available.  I have done it with MIG and its not strong enough, the weld breaks.  7018 or stainless rod works, but not near as well as the 680.When you weld to the stud like that, it heats the stud red.  The stud expands in one direction (the long way) and cools in all directions, so sometimes just that helps loosen the stud.  No need to cool the stud fast, it will shrink all its going to cooling slowly.  Mostly I have done this when the stud is froze in steel, not aluminum.  I am a mechanic, I have removed a lot of broken bolts and studs.  Keep the helicoils handy. Good luck.DavidLast edited by David R; 09-17-2007 at 06:11 AM.Real world weldin.  When I grow up I want to be a tig weldor.