Broken Head Bolt:

[bjperry]

Anyone have any good suggestions on how to remove a broken head bolt? I bought this motor (1978 150 v-6) a while back and have been working on everything pretty severely. I noticed it was missing a head bolt so went ahead and ordered one. Well, I inspected it today in preparation for putting the new bolt in and discovered it's been broken off about 2 inches deep. The only method I'm familiar with is drilling a hole in the bolt, threading an easy-out backwards into it and removing it that way. But if the bolt broke off to begin with I don't see an easy-out being strong enough. Not to mention that drilling a head bolt is going to be a job in itself. If that's my only option does anyone recommend a type of drill bit to use? Size? What about the type of easy out?

I'm open to suggestions and suspect that if not cured it will eventually blow a gasket right where that bolt is missing...

[Plainsman]

I just went trough the broken bolt headache. a good penatetrating oil and a lot of heat and you might get it out. I tried drilling, titanium bits, and broke the easy out in one of the bolts and a drill bit in another. I had 10 of them. I finally just took it to a machine shop and he had them all out in a day. Best of luck to you!!!

[emckelvy]

I wouldn't even waste time with an EZ-out, as the previous poster experienced it's just as likely to break off in the bolt, then you've really got a problem!

Best method is to carefully drill out the bolt, starting with a small titanium bit to get an accurate pilot hole, then moving up in a couple of steps to the final size. Since the head bolts probably aren't stainless, you may be able to clean the hole up with a standard-sized tap.

If the threads are all bugger'd-up, do a Heli-Coil repair. You can pick up the correct-sized kit from most auto parts stores or try your local screw specialty shop.

To keep head bolts from siezing-up, spread a very thin coating of Permatex No. 3 (Aviation-type) gasket dressing all over the bolt. Guaranteed it'll come out the next time!

BTW, given the broken bolt and no telling how long it's been running that way, it might not be a bad idea to dress the head out with sandpaper on a flat surface (i.e. piece of glass or similar), or have it professionally surfaced, to ensure a flat sealing surface and no head-gasket-blowing problems.

HTH & G'luck.......ed

[Plainsman]

You also just may want to call a shop and get a quote for them to do it. I bet I spent over $100 on bits, easyouts, oil and a small torch. Would have been better for me to take tot he shop from the beginning. But I really thought I could it and I can be stubborn 8)

[ragu]

why does everybody think that stainless is hard to work with? I work in a shop that makes stainless steel equipment and have taken out broken off bolts to big deal. here is one thing you can do make sure that you center punch perfectly in the center of the broken off bolt to start with otherwise you will be off center and will end up drilling into the side of your case next use a center drill and drill a starter hole then move up a size in drill bits till you can get to just under the size of the bolt use some kind of cutting oil while you are drilling to keep your drill bit lubed up and cool you dont have to run your drill at 1000 rpms either if you can get it drilled out to where there is just a little left in the hole you can try to pull out whats left of the bolt in the threads or take a tap and oil and try to run it down the hole 90% of the time it will work no problem just make sure you get started on center first thats the most important thing

[Scaaty]

why does everybody think that stainless is hard to work with?

Different metals in contact. Stick it in an aluminum block, heat, water, salt maybe, years of who know what, and you have what is presented. 21 years as a 1ST class machinist...know what they charge to EDM out a broken EZ-Out also? And SS is TOUGH stuff.. And the easy way to spot center here is a correct drill that fits snug in the hole, be it a Fractional drill, letter, or number drill...own them all, couldn't live without them..(Hi ED..."T" says Hi.. Robby)

[ragu]

put never seize back on all the bolts when you put them back in. If those bolts are stainless and you dont put anything on them you run the risk of galling and that really sucks also if you ever have to tear down again you wont have to deal with broken bolts scaaty not many people have all that at their disposal like we do probably better if he does take it to the shop i have seen some pretty butchered up stuff come thru our place also LOL something simple ends up lots of time