I have not done it, but collected up advice in case I ever do:
Do only as last resort! Person 1 Heating will actual increase the diameter of the hole. Heating makes everything expand; it's like adding a section to the doughnut. Both the ID and OD get larger (I lost a bet in physics class, so I remember this well). And assuming you can be gentle with the torch, it works well in practice too. Person 2 You will need heat. Use an industrial (much bigger than the handheld bottle) propane setup, not acetylene which embrittles the aluminum. You should use a good penetrating oil, like AeroKroil. You should use a real stud remover like Snap-on, or Hazet, sells. Immobilize the block at a comfortable working height and use good light. Practice by taking out the adjacent good studs. It will give you more room to work on the bad one and serve as a potential warning for things to come. Person 3 I have removed the studs from many Alfa motors - really no problem - just use a typical stud extractor tool and unscrew them from the block. It usually takes about 30 to 45 min. to remove all the studs. Person 4: I believe the process is called Electron Discharge Machining (EDM). I have yet to hear from anybody who has successfully used this on Alfa head studs. Intake and exhaust studs, yes, but not head studs. The problem is that the head studs are down in the bottom of a well and they galvanize themselves into place so well that even if you could get one out, the new one may not hold. For 2L blocks, it's usually cheaper and safer to just get another one. As the supply of early 1300 and 1600 blocks dries up, this may become a viable solution. I can see, though, that if you have to have ARP make up some head studs with special oversize threads at the bottom to make them hold, you're talking second mortgage. As I understand it, EDM depends on the fact that Aluminum conducts heat much better than steel. The steel gets heated so rapidly, it vaporizes, but the Aluminum never gets hot enough to melt. The water spray obviously helps drain the heat out of the Al. With Alfa head studs, the galvanic action in the hole may seriously detract from the heat conductivity of the Aluminum right at the point of contact. This may make EDM unworkable. Add to that the fact that the galvanic corrosion in the hole may reduce the current carrying capacity of the steel/Aluminum interface and you have another potential problem with EDM. The electricity has to come out the other side of the joint. Carl R. Davis 2823 S. Rocky Hill Road, Galena, Illinois, USA 61036 750E, 750F, 10121, 105.62, 115.01, 115.41S4 -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
