So I pulled the header to replace the gasket and check out what had become of the missing stud. Of course the reason was that the prior owner had broken one off AND had tried to drill it out. So what I found was a gouged out hole app. 1/2 - 5/8" in diameter with this stud still deep inside and the head material below and to the right of the whole is gone. So do I have any options besides a new head? I put it back together in the meanwhile with a "remflex" crushable gasket and ultra copper high temp sealant.
>>>*A pic would help me here but here is a trick that is slicker than butter on popcorn.
I have set the head up on my big rollover head master drill press, lock her down. I machine out the broken piece using whatever has to be done, then center up and drill and tap to whatever size the next clean mounting hole with threads will be.
Then mount a threaded plug, sometimes I just use a grade 5 bolt and cut it off after threading it in mounted in sealer. Sometimes if I have a nice chunk of aluminum laying around I will cut it to size and thread it and mount that, cutting a slot in the plug to allow a screwdriver to be used to seat it. That is best if through to the jacket, less chance of the head expanding away from the steel plug and ending up with a leak.
I have gone as big as 5/8ths on the Toyotas and even went through to a coolant jacket. I don't care about the coolant jacket, a good sealer on the threads fixes that. Much more than 5/8ths on some of them and you are getting into a port and that means either weld or discard.
Then I drill the stud mounting hole inside the plug itself, tap it out and and bolt her back up.
Of course it can also be welded back up and redrilled, but my way is stronger.
Bit of effort but worth it if the rest of the casting is sound.
I did that to an aftermarket Big Block Chevy head that was a $1000 casting once, the poor guy was off by 30? and already to 5/8ths plus he had broken off two tiny drill bits in there. I drilled a series of holes around in a circle, removed the chunk, it was so big I put in a 3/4" plug. His eyes were as big as silver dollars, watching what I was doing to his $1000K racing head...heehee..It was not only stronger than original but you couldn't even see it without a magnifying glass. (Well, I couldn't anyway...) It worked just fine and I got called a genious for that one. I just told him "nope, not a genious, just cheap!"... <img src="/forums/images/graemlins/lol.gif" alt="" />....*EB
