Carl, I am in awe of your knowledge and abilities (as I am everybody who can do this).  Why would a head stud fail like that?  It threaded in tight..did it pull out of the block or did the threads fail when you nutted the head nut on?  Is there a product a guy should use to secure "iffy" studs into a block?  Just curious about what might have gone wrong.

Carls_jeep wrote on 07/21/12 at 02:35:00:

Carl, I have to ask about the the use of Keenserts in the engine block:  When I was employed years ago by an aircraft manufacturer we used Keenserts when installing threads into an aluminum part.  Others on this site have talked about repairing stripped head stud threads in the block by installing a Helicoil.  Help me understand why you are using a keensert instead of a Helicoil in this installation.  

Sorry to hear of your setbacks.  I certainly wish you luck as you move forward from here.  

Here's an update on the stripped thread issue. I made a sleeve approximately the same height as the head and a gasket. I used an original type stud that was in real good shape and some new nuts I have but they are not hardened.



I then used the stud and nut with oiled threads to test the torque each hole will go to. With the thread oiled the torque value has to be reduced by 10 %. I used 60 ft lb for the setting on the torque wrench so that makes the real torque about 65 ft lb. To get an actual torque of 60 ft lb I would have had to set the torque wrench on 55 ft lb. OK, I started at the front of the block and worked my way to the rear. when I got to the "bad" hole, which is the one in the photo, it clicked at the 60 ft lb setting firmly. So, I raised the setting to 65 which gives 70 ft lb and it still clicked and was firm. I finished testing the rest of the holes at the 60 ft lb setting and none of them failed.

The only thing I can figure is the fine thread on the stud or the nut or both of them failed because the nut was locked solid on two studs and neither of those two hole failed the torque test. After all the years dealing with stuff like this I never am amazed but sometimes I am a little puzzled as to why stuff happens. Sometimes I spend to much time trying to trouble shoot a failure and figure out what happened and why when I should just get the job done. My curious mind won't let me let it go.

Well, anyway today I put some of the engine together and only need to put the pan and head on and tape up a few things and I can paint it then put the accessories on it. I'm thinking gloss black or maybe gray. I really like gray so it may be gray. I'll get some high temp black paint for the exh/intake manifolds. I may get the little bugger together this week and possibly in the Jeep next week end.

Man, I want to drive it so bad I can taste it.

Have you seen a photo of my Jeep? It's a Jeep looking for a restoration for sure. At some point I am going to have to pull the tub for some underside repairs and I guess at that time a lot of things will have to be fixed whether I want to or not. I just have to get it running soon to go to Utah.

Much has been said about expanding the bottom of the filler tube to make it tight in the hole in the block. Some have said to use a socket and drive it in the tube. So I looked through the large collection of sockets I have and none of them came close to doing the job. Perhaps there is a socket out there that is the right size but I doubt it. I am thinking that is an urban legend as well.

So I measured the hole in the block, measured the thickness of the tube wall, doubled that and subtracted it from the diameter of the hole and came up with 1.174". The wall thickness may vary some from tube to tube.

I went to the scrap pile and found a piece of 1" pipe that would work. I cut and faced it to 3.5" long, then turned 2" of it down to 1.174" and crowned (radiused) the end so it could enter the tube. I put the tube top down on a board and using a dead blow hammer I drove the expander into the bottom of the tube until it bottomed out on the shoulder on the expander.

Of course the expander was stuck in the tube so I used a ball peen hammer to tap around the tube over the expander until it loosened up enough to start moving. Then I applied enough heat to expand the tube so it came off the expander.

I installed the tube in the block and it was a perfect snug fit with no wobble. Job done and the engine rebuild is done and ready to put in the Jeep.

Really lookin' good!!

I, and I'm sure the entire 3A family have been glued to your engine rebuild for the past 3 months. Any chance of vidioing the final turn of the key if possible would be appreciated....
Great job Carl and great info along the way.

Carl, you are simply amazing.
Todd