I need some help, if somebody have experience with broken off cylinder head bolts.I tried to drill it but it is 10 cm long, i managed to drill 2 cm and put in stud remover, but no success.Tried by welding a bolt on it but the same result.The bolt is M14 in size. Any help is welcome.
Yair . . . kireeee . That bolt should come out with a proper welding technique. Find or make thick flat washer with an inner diameter slightly smaller than the stud, in your case 13mm. Centre it on the broken stud and (ideally with a TIG) weld it on. This has to be a perfect weld and you will need a good operator. If you don't have access to TIG use stick and a die grinder to grind out any slag and inclusions. It's not hard and any good tradesman should be able to get a good weld in there with a slight reinforce above the level of the washer. Now select a nut with an inner diameter that will fit over the weld and weld around the outside of the nut to fix it to the washer then get inside the nut and fill it up with weld. What you are trying to do with this last procedure is to transfer heat down into the broken bolt. Leave the thing to cool out to ambient and with a bit of luck you should be able to back it out quite easy. The main thing is that first run on the inside of the washer must be perfect. I have taken out dozens of broken off studs in this manner and have seldom had it fail. If you prefer to drill you really need a magnetic base drill press, make sure you have it centred and drill the stud leaving (say) a couple of mills of wall thickness . . . say in your case go in with an eight or nine millimetre drill then with a welding tip on the oxy apply a bit of heat down the hole but be sure you don't start any melting. As soon as it is cool enough not to catch on fire fill the hole with engine oil and leave it to cool to ambient before you try it with an easy out or better yet. a left hand tap. At this stage take it easy you don't want to break that easy out for the next move will be to drill it out completely . . . right out to the roots of the thread. you should be able to pick a few the threads out with an awl and get a start for a tap. It can be a long drawn out procedure as the slivers of thread will jamb you but provided you had the drill centred you should end up with a good serviceable hole. Keep us posted how you go with it and don't forget the pictures. (big grin) Cheers.
And before you do the welding suggested by Scrub above - heat up the broken bolt and the area around it until it's hot enough to melt a wax candle. Let the candle wax drip all over the top of the broken bolt, the wax will literally be sucked into the threads so that later when you come to put a spanner on your welded nut the broken piece of bolt should come straight out.
I've seen it done pretty much the same as above, but with a stick welder. As soon as it went back from red to that nice grey color, it was given a thorough hammering with a air chisel. If it wasn't so hot I could've backed it out by hand. Seems the vibration helped to loosen all the crud in the threads. Good luck
As stated above but I have had better success with a unichrome rod on a stick welder. They are extra strong and work good on studs.
I've used unichrome too. Usually when they are broke way down inside. Then I will stick a piece of pipe/tubing down the hole and then the welding rod down the middle to weld them together. Use a pipewrench or vicegrips to back it out. The unichrome rod sticks well with less than ideal conditions. On a flush break like yours the nut and washer method should work best.
Just my 2 cents... What Ive done in similar situations is drill the broken bolt to roughly 3/4s its depth and then filled the hole with a wirefeed using small wire, .030 or ,035. Usually that shrinks it to the point it will unscrew with the fingers when it cools. of course I weld the washer and nut on anyway.
Same here, but I thought it was best to hammer it immediately. Trying to deform the bolt when it's under the most pressure from the block, so that it shrinks more when it cools. Drilling sounds effective too, I'll have to try that one the next time I need it, after the welding alone fails a few times.
Yair . . . good stuff fellers, a couple of new ones there on me . . . but at my stage of track wear I hope to never have to use them. (big grin) Cheers.
I have a nice little side line going with a spark eroder removing broken taps and studs. Unless you have plenty of stud protruding I make welding a last resort and try other things first. The reason being as soon as you weld onto a HT stud it will go glass hard so its usually goodbye to drilling later on. I prefer to drill and if its hard you can use something like an Artu http://www.artu.com/drillbits.htm Then heat like others have said. If that will loosen it an ezy out may work.If it don't then try welding on a nut. If that fails I can run the spark eroder down and split the bolt and its easy after that. The best ones I get have been welded,drilled of centre with a broken off ezyout I can make a dollar out of those
Ditto to all above, also if drilling out a stud get ahold of some left hand drill bits. Sometimes when drilling the stud will just screw out. Bill