Bolts seized in cyl head

Oxy-acetylene or map gas torch. Heat them till they just glow then cool them with some water. Weld a nut on the end & remove. Normally welding the nut on the end & spraying some wd400 on the stud will get them out (obvious fire risk).

There used to be things (can't recall what they were called) that were made to extract such things. They were made of hardened steel and had a coarse left-hand thread. You had to drill a proper size pilot hole first though, to get them started.

Here's some US stuff - maybe google for UK equivs.

You can buy a specific tool to do the job. It's called a stud extractor amazingly enough.

'Easyout' rings a bell. If that's the ones you mean, they are tapered with, as you say, a course l/h thread. I'd advise anyone considering buying or using them to not waste their money. They just don't work. The tighter the broken piece of stud or bolt is, the more the 'Easyout' swells them, making them even tighter, and if the predrilled hole is deep enough, the Easyout can break. At that point about the only way to remove the broken stud, along with the broken Easyout, is to use a spark eroder. The last set I had. Picked up in a job lot. I gave away. Mike.

Or, better than a nut, is a flat bar about 3/16" thick with a hole about the size of the stud drilled in it. Weld the stud to the bar. If the bar breaks off, keep rewelding it until the stud gives up.

Rob Graham

I'm glad it's not just me that had no success with them :-)

Chris

Be very, very careful how you proceed. The head is a light alloy and the stud is usually steel. Hence your problem. I don't think you'll get this done in a couple of hours unless you want to get into a hissy fit and wreck the head. But hey, it's January and the weather's miserable. :-) (Says he who took his bike to work today).

Start by soaking, and I mean soaking, the studs in WD40 or duck oil or similar. Do this for a few days. Then follow the advice given to weld a nut on the end. Make sure it's a weld that would hold the Queen Mary. If it is still being a shit, try tightening the stud. Not much, just an eighth of a turn or so. It's sometimes enough to free the corrosion and get it going.

IMO they're the mechanical equivalent of snake oil. A better alternative using a similar principle if the break is flush with the surface, is to drill a hole down the centre, knock the tang end of a suitable file into the hole, then using Mole grips, or a small spanner etc, as close as possible to the broken stud, try to unscrew it. I've found this method successful with all but the tightest studs. A much better way than using Easyouts, with the advantage that if it doesn't work, you don't finish up in a worse situation than you were when you started, as if it doesn't work, all you finish up with is a tapered hole a bit bigger than the drilled hole. Mike. .

You can drill the easy outs out with a carbide drill in a dremel. They don't work if the bolts seized, but if you drill the full length of the bolt you can often unseize it in the process. Then the easyout lets you get a grip on it. However left hand cutting drill bits do both jobs in one go without spreading the bolt.

Ever tried drilling out an Easyout with a carbide drill? IME a tugsten carbide drill, unless it's a much smaller diameter than the Easyout, will just slip off centre, and start drilling the piece youre trying to save. You don't need to go to the expense of buying l/h drills. IME again, a r/h drill bit ground to cut l/handed, works almost as well. Mike.

That's why the modern ones grab the outside of the stud. As long as there's a few mm protruding, you can usually get them to grab on.

Yes, that's why I said it. In general I've found the 4 flute really steap angle easiouts worked fine, the cheap chinese ones, as hard as glas with a very shallow thread angle are useless

I normally spot the top with a grinding tip first.

Well they've never cost me very much :-)

What a splendid little article.

Many thanks for sharing, I KNOW it will come in useful VERY soon.

Tom

MIG a nut on, it'll give something to grip, but it's the heat that'll do the trick...

In article , Dave Baker writes

Handy. Many thanks, Dave.