Posted by Vince Falter on Oct. 18, 1998 at 16:16:51
In Reply to: Re: head studs
posted by carla on Oct. 18, 1998 at 14:03:36
Another trick is to reinstall the head on about four of the studs to locate it, then use a drill the same size as the stud holes in the head to find and start the center of the broken stud, or, you can start with a smaller size drill using a drill bushing in the head stud hole. They are about $5 at the various tool supply houses around Detroit. Also, If enough stud is left to get vise-grips on, I've had good luck heating the stud up dull red, let cool, heat stud again, let cool, etc to loosen it in the block. The theory is that the stud trys to expand uniformly under heat, but can't due to the block. It mostly expands lengthwise. But when it cools after lengthwise expansion, it shrinks uniformly, and loosens in the block. Two or three coolings seems to work.
: hello, gg, : mr chauvin makes some good points, but it may not be as bad as all that--- there are a few things you could try first-- i'll guess that you have a little propane torch and a four lb. hand hammer-- if not, they are cheap and readily available-- you block the propane torch in position to let it run on the stud awhile til the stud is at a black heat--- not to even a dull red, then let it cool just a bit as the heat transfers to the part of the stud thats in the block--- then grip the stud as near the block as might be with a large pipe wrench and exert a steady strong pull as your helper strikes the top of the stud with the hammer, taking care to strike the stud in a vertical direction only, that is, directly towards the block and not in such a way as to bend the stud-- the top of the stud will mushroom, but thats alright, cos the stud is scrap anyway. : should the stud break flush with the block, then it should be machinists' work to remove it, but if you wish to try it yourself for the learning experience and don't mind investing a few dollars in tooling, read on--- centre punch the broken stud very carefully on centre, then drill it with a small (say 1/8" or so) drill-- a new, sharp, best quality high speed drill, taking care to hold the drill motor so that the drill is square with the block-- have a helper hold any little square object near the drill to guide you, to maintain squareness. be very certain to drill no deeper that the thread length of the other studs-- stop and check depth carefully. : then follow with larger drills, being careful to be very certain that you don't get near the threads --- your drilled hole will go out of centre a bit, inescapably, so drill out in small steps, say, 1/64" at a time. when you see that the hole is getting near one side of the threads, use a small rat-tail file to adjust the position of the hole. continue this until you are near -- but not cutting into-- !!!! the threads. : then try an easy-out-- use only the "tapered square" type sold as the "proto" or "armstrong" make -- never even consider using the "tapered twist" style-- those are a snare and a delusion. : use a bit of discretion when hammering the easy-out into the stud. : after the broken part comes out, use a new, sharp, best quality 7/16-14 second or bottoming tap to clean out the tapped hole-- reverse the tap a bit every half turn or so to be certain to keep from getting the tap "stuck" in the tapped hole. : carla |