Broken Head Stud.

[s147881]

I pulled the engine from my 1930 model aa stake truck. I removed the head and the pan to check the bore and the bearings. The bearings all plastic gauged at .002, mains and rods. There was no ridge in the cylinder and the bores looked perfect. This engine has sat in this truck for 50 years outside in Wyoming and is in great shape. When I went to reinstall the head, I broke one of the head studs. It is broken level with the engine block. Any ideas on how to get the rest out? I ordered a new set of head studs and plan to replace them all. Any tricks on getting them out without breaking them?

[Chris Haynes]

I take mine to a friend who is a whiz with a heli ark welder. He carefully welds a blob on top untill he can weld a nut on it. Then you put a wrench on the nut and remove the broken stud.

[E.Moore]

The best way to remove a broken head stud that is flush with the block is to put the old cylinder head back on the block, then use a bushing that can be either made or bought at a hardware store to fit your first drill size (1/4") or smaller.

The bushing should fit the stud hole in the cylinder head and the inside diameter of the bushing should fit the drill bit.

The bushing is the centering device for finding the center of the broken stud.

After the hole is drilled, another bushing will need to be installed for the next size drill bit.

When the stud has been drilled out close to the threads, use plenty of liquid wrench or something similar and a tapered square EZ out.

Sometimes a stud will have to soak several days before the penetrant has had a chance to get down into the threads.

If the broken stud refuses to come out, it will have to be drilled completely out and a heli coil will have to be installed.

This is the method that good machine shops use to remove those nasty studs.

[Chris Haynes]

Then when you break the EZ Out you take it to the welder.

[s147881]

I was able to remove all the old head studs but broke a second one off. I drilled and tapped out the first hole and it came out perfect. The second broken stud did not go so easy. I drilled it with a small drill. When the drill bit broke thru the bottom of the stud it hit the bottom of the hole and broke in the hole about 3/8 of an inch from the top. I was able to continue with larger drills to get the hole drilled out to about a quarter of an inch. This allowed me to put an easy out into the hole. Over the next 3 days I soaked with penetrating oil, heated, tapped the stud hole with a small punch and a 2 lb hammer. Each day I would try the easy out and try to see if it would come loose. I was very careful not to put to much force on the easy out to prevent breakage. On the third day (Today) the easy out broke in the hole flush with the surface of the block. I took the short block over to a local welder and he looked at it and said no problem. He will weld a nut on it tomorrow and remove the stud. I hope this works. More later. Attached is a picture of the engine 2 months ago.

[s147881]

The welder called me and was able to remove the easy out but could not remove the stud because I had drilled it down in the block about 3/8 of an inch. It is not at the machine shop - hope this works.

[Chris Haynes]

As I said in the beginning. Take it to a welder and have a nut welded onto the stud. EZ Outs break more often than they work. A compentent welder can build up the short stud to the top of the block and then weld the nut on to it.

[s147881]

A local machinist removed not only my broken stud but also removed the 6 remaining head studs I had given up on. I will be installing the head soon.