Whats going on fellas. I recently got a 79 cutlass with a 350 rocket, and i have the worst luck. I had a broken head gasket, so on the process of putting everything back together, as im about to torque back the heads i look up to see the torque specs for it, it say 130lbs...freaked me out a little but thats what it said. so as im doing it a break a freaking bolt!
now tell me guys, how hard is this to repair, or how much would a shop do it for?

any help is appreciated!

 

If I'm reading this right you broke a head bolt by over-torquing it, right? If that's the case pull the head back off. I'd guess the bolt broke off flush with the block. This is kinda' hard to explain but here goes. Use a sharp center punch and ball peen hammer and tap the bolt stub counter-clockwise. It's easier if you make a punch mark just in from the threads. Then use the punch mark to tap on with the punch leaned over at about a 30 to 45 degree angle. If it turns a little it will come out. Just be careful to stay away from the threads in the block. Once you have about 1-1/2 to 3 threads out of the block you can take it the rest of the way with pliers. Note: This only works with bolts that were over-torqued or sheered off. Not rusted bolts

Try just turning the bolt stub by hand. I sometimes have luck just pushing down hard with my thumb and turning.

They also make left hand twist drill bits that work good for this. Just center punch the center of the bolt. The left twist works with the drill in reverse. Just start drilling & the bit will catch and back the bolt out. Only problem is, I can't tell you where to get them. I borrow one at work when I need one.

Don

 

Forgot to mention, when you have the punch leaned over to tap on you want to be pointed slightly towards the center. Not towards the outside. That way if the punch comes out of the mark it won't damage the threads in the block.

Don

 

And I forgot to say welcome to the site!!

 

awesome man, thanks alot. i thought this was worse cause when i took the bolt out the screw on part was gone and i was like ***** how am i going to get that out now, but tomorrow i will def try that and look for those drill bits. again thanks

 

I learned the punch trick in about 79 or so getting sheering axel bolts out on a 2-1/2 ton dump truck. Didn't learn about the drill bits til about 2-1/2 years ago. And when the drill bits don't work I use the punch. Might be worth a try before you try to track down those bits.

Don

 

DON'T USE AN EZ OUT FOR THAT HEAD BOLT! Sorry to use all caps but I can't stress enough how crappy EZ Outs (or left handed bits) are! If you use one of these you will end up breaking the EZ Out off in the head bolt and then it will be stuck in the block FOREVER! EZ Outs are made of super hard steel. As such they are very brittle and tend to break often. They are supposed to work well but I have never had any luck with them and have only heard bad things about them. I suggest using the punch and hammer trick and if that doesn't work you can tack weld a smaller bolt to the broken off shank and back it out with that. EZ Outs are bad news!

 

i still havent gotten the bolt out, but i was thinking. what if i drill a hole in the middle of the bolt and if successful hammer a screw driver in the drilled hole and attempt to get it out like that?

can that cause any damage?

 

Yes. This is the route I would take. Once you get it out, I'd also go get all new bolts from ARP because those stockers are all stretched out.

 

Not likely. Head bolts are grade 8 or nearly that hard.

Olds64, (Jesse - I think) I do industrial maint. by trade. You could be right, I forget guys don't do this type thing. I do it w/o thinking too much about it. Got a broken bolt, get it out, run a tap in the hole and move on. But remember we're talking about a bolt that was broken from being over-torqued. Same thing as a sheered bolt. The threads on the bolt stub and in the hole are OK. Rusted or any bolt that broke while being loosened is a different story. In that case the threads are the problem. Oh, have you tried the weld a bolt on trick? We usually weld a nut on through the center. But if not in the shop where we can use the MIG it's a major pain. And we have a special "Extractor" welding rod for doing it in the field. It's not so bad if the bolt is larger, like 3/4" dia. or bigger.

I'd say 75 percent chance in the time it took me to type the first reply I could have had the bolt out. With a good center punch and a hammer. Raymond, try it before you drill it.

Don

 

well guys as soon as i asked the question with the drill and screwdriver i went out side to take the head off, and well i was surprised to see the broken bolt sticking out to the point all i need is pliers, but i cant find any to save my life, so i tryed what Dapapadon said with the pushing down hard on it and BAM! i got it out. thank you so much man for all the advice you gave me, and the rest of the guys!!..now to buy new bolts, but i went to the autozone car parts site and it gave me the set for $111, is that right??...seems really exspensive

 

I think $60 is about right.
You need to know if you have 7/16 or 1/2''

http://www.hdmaddog.com/Shop/Control...d/0/rid/125469

Summitracing.com will probably have them for $75 plus shipping

 

AWSOME! It is always a relief when a fellow car enthusiast overcomes their problem. I was just shooting a warning about the EZ Outs because I broke one off in my exhaust manifold. Oh well... at least I am in the middle of a rebuild. I will probably buy headers anyways.

 

I also snapped a head bolt years ago, the cause was water in the hole from collant that spilled when I pulled the heads. The bolt came right out when I bumped it with a chisel. I couldn't believe that water would do that but water is not compressable.

 

If you have to drill it out there isn't much chance of saving the threads unless you're real good, can be done, Heli-Coils are a last resort. I had a '57 Chebby and almost all the threads for the head bolts in the block were stripped, I drilled and tapped them and used Heli-Coils inserts and they worked great. A lot of guys used to install Heli-Coils even if the threads were good, guess they're stronger than the tapped block?

Allan

 

If the hammer and punch does not work, try slotting the end of the broken bolt with a Dremel tool and using a big screwdriver to unscrew it like, well a screw...
I have extracted my fair share of busted bolts and screws this way.

Just make sure to keep the filings from going where they are not wanted.
And again, this is for only over-torqued bolts.
Good luck to you!

 

That is an awsome idea! I have never heard of that before.