LAST bolt I was torqueing... Waiting for the click from my torque, wrench but instead heard a "SNAP!" We drilled about 3/4 down into the bolt, inserted an "easy-out" and the easy-out snapped off in the bolt... ANY and I mean ANY suggestions would be of great help... The last thing I want to do is pull this head off and ship it to the machine shop..

But that probably is the best thing to do.

Dont resort to anything too drastic just yet, ill talk to my freind and see if he can tell me the name of the tool/company. He broke a thermostat housing bolt on a offenhauser aluminum intake manifold that is no longer produced. A neighbour loaned him a kit, its kind of like a drill bit with "reverse threads". You start tapping into the thread portion of the broken bolt, but to tap, you turn counter clockwise, because of reverse threads. Eventually it will get tighter and tighter, and the force to tighten the tap will exceed the force to loosen the bolt. Since they are both turning in the same direction, the bolt will come loose.

Worse comes to worse, you can always drill and tap, not the end of the world,

Too bad that someone doesn't make some sort of very hard, slender cutting tool which can be spun at high speed to machine a hole in the broken bolt.

What would be even better would be devising another tool which could be placed in that hole to form new threads, so you wouldn't have to remove the head and take it to some specialized automotive dungeon where they perform some kind of black magic voodoo on it to restore the thread.

It would be a very simple and easy repair, if it weren't for the EZ-Out broken off in the bolt, and the off-center drilling that's already been done.

The way to fix a broken bolt is to center-punch the remains, and then starting with a very small bit (like 1/16"), drill it out with successively larger bits until you can either clear the remnants with a tap, or drill it to the correct size for a thread insert. I usually end up with an insert, most often a Heli-Coil because that's what I can most easily get.

I have NEVER, not even ONCE, had any success with an EZ-Out in that situation, precisely because of what just happened to you. I don't even own any of them any more. They ALWAYS seem to break off, and then of course you're left with something harder than a drill bit stuck in there. But even that could be handled with a $$$ really hard $$$ drill bit set, using the techinque described above. But now, with that stupid worthless POS stuck in it, about all you can do, is take it to somebody that has the right tools.

Yes, thanks for your help.

Sofaking is right, i think it WAS called EZ-out, ill confirm once i talk to my bud. He is onto something though, with the way that hole is, you may not be able to access it with an EZ-out, and if u break that, then uve made it really hard.

Up to you though, maybe drilling with larger bits sucessfully is the right way in this instance.

I feel for you though man, thats the last thing anybody wants to happen. In future, id take a tap and run it through all the holes, then blow compressed air in them to blast all the **** away. Gets you proper torque specs.

Yes, EZ-Out it what I used, and EZ-Out is what broke off in the bolt... I know how and why the EZ-Out broke off, Just need to take the proper steps to remove it.

I agree with Sofa. You're probably best off taking it to the machine shop. I would imagine that EZ-out is hardened steel, just like a thread tap. I've been in the same situation many times, and it's damn near impossible to drill into hardened steel. Even if you manage to drill into it, you usually get off center and screw up the hole and the original threads. There is one thing you can try before giving up and seeking professional help. This actually worked for me one time. If you can find a sharp pointed center punch that's made of really hard steel, you can put it right in the center of the broken EZ-out, and smack it hard and quick a bunch of times with a hammer. Since the broken piece is hardened steel, it's actually brittle, so if you hit it right with an equally hard punch, it can actually shatter the broken EZ-out piece. I did this successfully with a broken off thread tap once. An air hammer works even better for this if you have a small enough tip on the end of it. If you can get that out, it'll be easy to drill through what's left of the original bolt. You want to drill it out as big as you can without going into the original threads. Soak it really good with PB Blaster, and use the biggest EZ-out that will fit in the hole you drilled. Tap it in there with a hammer to get it in there as tight as you can. Judging by your pictures, you used way too small of an EZ-out, and they break too easily. Besides that, the broken bolt actually kinda collapses inwards some once it's drilled really thin, making it looser in the hole. Good luck!

Well, I'm wondering if the best thing to do would be to pull that head off and ship it to a machine shop. . .

It would be different if the bolt had been drilled off-center, or if an Easy-out had been broken off in it. . .


(In case you couldn't tell, that's sarcasm. Nothing personal, mind you, but I think you knew the answer before you posted. I can understand wanting to get off easier, but you're beyond that now. Time to face the music and do what needs to be done.)

Just curious, was that an ARP bolt?

No, just a stock Vortec intake bolt

Sorry guys, didnt pick that up right away just by looking at the pix. I think faster than i do/read so it doesnt always go in the first time. But yea, ill have to agree with five7kid here,

if youve broken the EZ-out, and its offset, youve pretty much had it. Clearly youre not equipped to handle the original task, let alone a mishap along the way. I would bite the bullet and pull the head at this point, atleast its still salvageable, you dont wanna take a chance at making it worse.

Took no more than a few hours od drilling and using the Dremel to grind everything out. We got both the EZ-Out and the bolt out. For safety reasons, we drilled and tapped the hole to a 3/8, so now it takes a standard SBC intake bolt...




rofl... "pull the head" .... hahahaha

[rofl... "pull the head" .... hahahaha] Damn, you try to give a guy good, sound advice, and he ends up scoffing at everyone because he got lucky. I'm glad you managed to fix it without having to pull the head. I think most of us were simply trying to give you the best advice possible in case it ended up being a royal PITA, which is usually the case more often than not. If that's the kind of thanks you get, I sure ain't gonna bother to give away any more tips on how to deal with such a problem. What a waste of time typing all that crap. Lesson learned here.

It was the fact that immediately almost everybody had said that it was going to be impossible and that I should pull the head. Apologize if that was coming off as being a ****, that was just aimed at someones smartass sarcastic comment above...

That probably would have been me, and as 5-7 posted, it seemed that you already knew the answer to the question. You didn't come off as a ****, or anything else which the board filters turn into asterisks. If we can dish out a little banter, we should be able to take it without being offended.

I'm glad you persisted and got it out. I might have tried drilling a few smaller holes around the periphery, then using a tap extractor, but not everyone has those. You usually acquire those after really screwing up and breaking a tap in a blind hole. That might not have worked, either, so your method is reasonable, and seems just as effective.

Now that the hole is cleaned out, if you really wanted to restore the thread, you could drill and tap it larger, and install a thread insert (NOT a Heli-Coil) and have your original thread pitch and diameter back. There should be plenty of material around that area to allow it. If not, the one 3/8-16 bolt will be just fine, no one but you will ever know, and we'll never tell.

yes, thank you.


and I apologize to you guys who just tried to help. Thank you

Unless posted, we really don't know of the person's tool availability or skill level. We just have to guess based on the way the question is worded.

Of course, you didn't get any filings in the engine during all this.

Glad you got it out and can put the engine back together again.

Man, glad you got it. But is it just me or is it always the last bolt that decides to do something like this?