Packard Forum Index » Post-War (1946-54)

When i removed the manifolds from my '52, I found that one of the bolts (the first short one away from the firewall) was broken off right at the block.
Now I am getting ready to re-assemble and need to deal with it. It is fairly hard to reach and a jagged break. so centering and alignment is going to be difficult.
It looks to me as though the stud does not extend into the water jacket, but still a difficult job.
I may try to make a guide from some 90 degree material, that I can bolt onto the head stud almost directly above the broken stud to keep it somewhat aligned and guide me to the center of the broken bolt.
Any suggestions will be appreciated.

In the past I have used die drills with cutting fluid. An air drill. You will need two or three sizes, starting small to larger. Making two or three cuts. Bad news die drills come from a seller like MSC Industrial and are more expensive than normal drill bits. They are hard but brittle, you cannot bend them at all or they will snap. Using the cutting fluid you can drill a stud by hand in about 30 seconds.

Perhaps put the manifold back on just snug with no gasket and use the actual manifold hole to guide your drill. I have used this method a couple of times to remove broken head bolts when I did not have a Mill available. Do start quite small and come up only a size or two at a time...Please don't be in a hurry. Good thoughts, Ernie

Some of these come out and some don't and then drilling out is the only option. Another site told a guy to go to machine shop but they overdrilled and put a big threadsert in and messed it up, leaked coolant, so be careful.
I doubt you'll want to pull the motor for this. But may want to remove what's in the way, if a close quarter.
I'd take a small grinder and clean the breakage first as best as you can to get on/find center.
I like the reverse drill bits and square easy outs and lots of penetrant. I don't like heat on cast just my experience. Sometimes, if easy, the reverse bit takes it out alone.
I broke a spiral easy out off on one, and that presents a larger challenge and special carbide cutter to remove. Seems I get a better grip with the square, and lightly tap in tight before turning. One has to be careful to not bend or over leverage when turning. If it won't go small, go up next size and at worst, used the thread hole size bit from tap chart and pick out the remaining threads. Then chase threads.

Google it and checkout some of the youtube videos. An easy one that I saw was to weld a nut on top of the broken bolt. Hard part would be holding the nut center on the bolt. But like I said checkout the videos before you start a lot of good ideals out there.
Wes

I have successfully removed broken studs by welding a nut to the broken end but I would not try it with the engine in the car unless you can be very sure there is no risk of igniting the fuel, I am not sure that's possible.

This hasn't gotten any better. I talked to a number of people about arc welding a bolt and screwing it out, but the access was a little difficult far anyone to want to try it. I used various sizes of drill to go through the stud, but none of the easy outs would get a good enough grip to pull this out. They definately got a good grip, but the stub would eventually deform and loose the grip.
I am trying to locate a larger and longer extractor to use as i can enlarge the hole a bit more - I am at 1/4, the stud is 3/8 I think. a 1/4 extractor will not grab. Plenty of PB blaster has been used, but nw with the stub drilled, it just goes into the water jacket. I do seem to be pretty squarely in the center of the stud, so i guess if i have to , I can drill it out to just below the stub size and chase the threads. Hoping an extractor will work first.
Any ideas are appreciated.

If you are still using pb blaster or some penetrating oil, you can also hit it with a hammer a few times, and also heat it up with a small propane torch. I like to go through a few cycles of hammer, heat, oil, hammer etc.
If you remove the shield from the inner fender (the one used for valve adjustments), you might have better access.

I have also seen people melt a stud out with an oxy acetene torch. I don't know the process, but when I saw it once 25 years ago, I was amazed. He heated it up for a little bit, and turned one of knobs on the torch, the flame went out and the molten stud just ran out of the head onto the floor.

Quote:

Mike,

Thinking, and no doubt I'll be proved wrong, that maybe he turned the acetylene off just leaving oxygen to "fuel" the heated stud.

Fire away!

Heat the stud using mapp gas. Concentrate the heat on the stud. When hot, apply a liberal amount of candle wax. Tap in the ez out, and rotate using steady pressure.