CRAP! Busted alllen head bolt from head to block. What is the best way to get it out?
 

Okay, changing the head, HG, exhaust, front seals etc. All was going great until one of the front bolts, at the black to head water jacket, twisted off leaving the stub in the block. I've never had a problem like this one. What's the best way to remove the stub without pulling the block and sending it out? Here are the pics plus HG and head carnage!
Thanks in advance guys. I need to get this out tomorrow, so I need quick help!

OH the stub in question is at the top center of the first two pics. The others are the HG, which we think was either just old, or there as a bit of head warpage and the last is of all of the crap on the valves. Thought some scoring is visible on 2 and 3, (I haven't checked 1/4 yet, you can't feel the scratches even with a finger tip, much less a nail, so I'm feeling good there. Front crank seal needs to be replaced so, that is another bit of work.
Anyway thanks guys!

I can't see any pics but if you can pull the head and get to the stub you can use vice grips. Or you can weld a nut onto the stub just be careful to weld the interior of the nut. Also there are removal tools that thread onto the outside of a stripped bolt. Or you can drill into the bolt and use an easy out. Whatever you do try to use some heat to make it easier

Just did it with a acetylene torch and vise grips. Came right out. Brute force with no heat will result in a F*&k situation. Obviously if you break off the nub you'll be really screwed.

If you have the enough protrusion the stud/nut removal sockets from Craftsman work great. I would still heat the surrounding area with a Mapp before doing it to help break the bond. Whatever you do, DO NOT use and Easy Out. GL Elliot, you deserve a break.

+ a million on the no easy-out advice. It will snap off any make things way way worse. If there is a stub sticking out, you can put a nut over it and weld the nut on if you have a MIG handy, or vice grip it out. If it is snapped flush, then I've found the best thing to do is to drill it very carefully. Start with a small center hole, taking great car to center it, then make the hole bigger and bigger until you can either tap it to the original size (basically scooping the old bolt out). If you can't tap it out, then just drill the threads out for an M8 helicoil. That bolt only torques to 14 ft lbs., so a helicoil is more than solid enough (in fact, much stronger than the original aluminum treads). I've helicoiled those very bolt holes with no problems...

alright! pics are actually up this time, in the first post. I don't think I had the patience to wait for them to upload. lol Anyway, they are up.

lol. Not sure I actually deserve anything, but I'll take what I can get! ;):roflmao:
I'll check on the removal tool.

Shouldn't a small hand held torch be enough for this?

I think I can get a decent grip with vice grips. It's a bit more than a 1/4 inch protruding.

Now that pics are up, I'd love to hear ideas on the failure mode.

Thanks Tom. I've never done any work with helicoils. What are the basics that I need to know.

BTW THANKS! I used your HG write up, combined with Van's vids. Other than this damned bolt, it went smooth as silk. Once this is out it's just a matter of cleaning up parts, etc. and re-asembly. The bores look quite good. I post pics of those tomorrow. The pics I have were blurry.

That looks exactly like the one I had. I tried welding a nut on, but the metal was so weak, the weld just crumbled like powder, so I had to drill and helicoil it. Not too bad with patience, and all the national autoparts places now seem to carry helicoils...

Oh and do any of you know the PN for these two bolts? I need to replace both, not just one. The other came out but looked awful. I'd like to replace the with a hex head, if anyone knows the size. I presume that they are aluminum or some sort of galvanized steel?

I broke off 2 of the 4 waterpump studs, of course they were the two that go through to the water jacket. I picked up a helicoil kit over at Pepboys that included the helicoils, installation tool and tap. To make it even easier, the instructions specified a SAE drill bit to drill out for the metric tap. Because you're working near the waterjacket like I was, I recommend you use some painters tape and cover the bores and waterjacket. It'll make keeping aluminum shavings out of important places much easier. Just go over the area after you're finished with a shopvac and it's all gone. And make sure you get a helicoil long enough for the hole you're drilling out because they come in varying lengths and you can't stack them on top of each other.

When I replaced mine they were original and they were zinc coated steel.

Good luck getting the stud out, don't be afraid to drill and helicoil it.

I did some quick reading. I think I'll go with the drill/helicoil method. I just can't find the damned bolt specs in PET.

It looks like you've got enough protruding - I'd try Vise-Grips personally. Save drilling and stuff for a last resort, as there's always a good risk with that of drilling in crooked and screwing up the threads in the block there.

Soak it for a bit (overnight) in PB Blaster to try to break it down and loosen it up a bit.

As long as you center punch the exact center and work up in drill sizes, you can usually get the remains of the original fastener to fall apart before you get to the threads.

They are missing in PET. See here for details though:

https://rennlist.com/forums/944-turb...lt-on-pet.html