It looks like there is about 1/4" of the end of a bolt down in the block. How it broke off that way I will never know-faulty bolt? What must I do to get that out without drilling too far and punching through to the water jacket? I do not have a big drill press, so that is not an option at this time.
Not a whole lot of information here Dave?
Is the head off? Can you measure the depth of another bolt hole near by? If so, you can mark a drill bit as so not to drill too far.
I'm sure others will chime in here soon with better ideas.
Try this search I did.
This is a most common job in a machine shop. So do
as Dennis said measure a good bolt. Next find a
bolt the shank size of the broken bolt. Next cut
off the threads leaving just the head and shank,
next grind the end to a point. You have now made
a home made center punch. Just trying to drill without a true center can never be done with a
hand drill start small keep increasing drill size
getting near the treads. Snap On easy outs work
well Not the spiral type (they just expand threads
making them tighter) get left hand drills many come out just drilling. Not bad of a job, just wait till you do a modern crap box manifold many
of those the engine comes out. Sometimes when close to the (stuck threads) we stick a torch
in there, it wont bother the block but heats up
whats left of the threads, then just pluck them
out. Then clean up with a tap.
out without a easy out.
disregard the last sentence "out without a easy out" I dont know how to edit= that was a typo
This type of sleeve and drill makes it possible to use the head as a guide when drilling out the remaining piece of a bolt: http://www.snydersantiqueauto.com/5612
This method will only work on an iron stud in a cast iron piece. It's difficult to get a regular welding rod to stick to cast iron, so there is no danger of welding the stud to the cast iron.
I have used an arc welder and placed a washer that is the same size as the hole and built up the stud piece until the washer is bonded to the stud. Then weld a larger nut to the stud. As it is cooling, use some penetrating on it. Let it cool for 15 minutes or so, and back the whole mess out.
The heat from the welding will loosen up the bond of the rust on the threads, and the oil will penetrate easy. As the piece is removed some times it works better to tap on the nut and move forward and back as it is removed.
I have only used stick welding, haven't tried wire feed. I have removed several dozen using this method in the distant past and have had 100% success.
I thought I had a broken head bolt down in the block a long time ago. Turned out to be compacted goo and not metal! Soak it with your favorite penetrating oil overnight and dig around with a pointy scraper to be sure.
I sheared off a head bolt and used the tool like the Snyder's tool. It did the job easily. I recommend it.
Jim's method is one that I've used on many applications as well. The heat often helps loosen the stud. The drill guide in the head bolt hole if there's room is a great idea as well.
Welding the washer and a nut is my SOP.
und zo und zo und zuch und zuch
Dave ... take a 7/16 short bolt and drill a 3/16 hole in it on the lathe. Screw that in and use as a guide. Drill a pilot hole in the busted part. If you can manage to use a left hand drill all the better. It may bite and unscrew the stub. When the drill breaks through the steel bolt youll know it. Theres a gap between the steel and cast iron. Now you have a centered hole to work with. Drill it to the correct size and retap. Actually once tap drilled itll probably collapse with a pick. Retap to clean it out after the bottom goo is broken loose. TAP all the holes clean, water neck included.
In all actuality, this took longer to explain and type than drilling the bolt out!
And now the secret... like a left handed drill, use a left handed tap. I know all the guys calling the diner for Barney have a set in the tap drawer. If it feels too tight and it may break the tap STOP and continue as above. This is wayyy beyond O rings on the space shuttle. ws
The guide bolt with a hole down through the center is definitely a good idea to be certain your new hole is centered. It also provides a means of getting penetrating oil down to the other end of the seized stud.
Like a lot of people, I've had zero luck with Easy Out's. I call them Never-Out. An old machinist showed me a superb and simple alternative.
Go through your collection of Allen wrenches until you find a size that fits down into the threaded hole with some clearance. Wrench size should be as big as possible, but not big enough to get near the threads. Now, drill out your broken stud until the center hole is just smaller than the Allen wrench. The hole should be larger than the distance across the flats of the Allen, but not quite large enough to get the Allen into the hole. Say, .010 to .015 smaller than the large dimension of the Allen.
Cut the 90° end off the Allen wrench so that you have only a straight piece of hex stock. Grind the end of the Allen nice and square, leaving good sharp corners.
Now, drive the Allen into the hole in the broken stud. Drive it all the way through the length of the broken stud. The corners of the Allen will broach nice grooves into the hole without exerting any expansion force as an Easy Out would do. Driving the Allen into the stud will also help break the crust or corrosion that is locking the threads. Then put a Crescent wrench on the protruding end of the Allen and unscrew the broken stud.
Im gonna remember that one! Especially for smaller stuff. Ive used old square chisels on bigger stuff but for skinny jobs an allen wrench is perfect! ws
If all the above fails (which I hope it doesn't), there is a fool proof solution. A couple of years ago I broke valve guide "knurler" off in a block. Now this is made of hardened tool steel. It is not drillable with any thing I had. So I talked to my friends who ran local machine shops and was directed to a outfit who did this type of work using a EDM (electrical discharge machine). They were quick and reasonable. Yes it certainly absorbed any profit in the job, but it kept my client happy and saved his block. I hope I never get caught like this again
Here is a tool Langs and Snyders sell, I supply it to them. It is a copy of a Stevens T-200, they sell them for about $35. Uses the head as a drill jig to center a drill busing to drill out the broken bolt, then take the head off and run a tap to chase the threads.
Beware of easy outs or other hard steel / tool steel bolt removers because if you break it off in the bolt you will not be able to drill through it.
That's a Jim Dandy tool set Jeff, but, the holes in the head are probably 15/32" (7/16 bolts?) and you can massage the head position around a little bit. This kit is good for not pulling the head, but if its off, Id prefer a threaded guide bushing in the block for individual accuracy purposes