After reading the other replies, I realized I should provide additional info on my experience with removing the exhaust manifold studs from the block. I've tried a lot of different techniques over the years starting with a 62 F-85 aluminum block while a teenager. I would summarize what I've learned as follows. 1. The best ways to break loose the bond between two metals are heat, impact and penetrant. (I'm still amazed at how a couple of firm hits to the side of the steering knuckle will loosen a tie rod end!) Hitting the end of the stud (assuming there's something to hit) is the start of an insurance investment against the stud breaking in the block. I feel the next step to breaking the bond should be applying heat. A propane torch may not provide enough heat but a mape gas torch will. I suggest using a torch that has a flex hose between the mape gas tank and the tip to fit better into the tight space and keep the tank upright. A mape torch is also an inexpensive purchase compared to an oxygen acetylene torch. After heating the stud, I let it cool then apply penetrant a few times over 2 or 3 days. I've NEVER broken a stud off in an aluminum block using these three steps before attempting to remove the stud. 2. If the stud is broken inside the block, I've had the best success with the following: a) as someone else suggested, carefully center and tap the stud with a punch to provide as accurate-as-possible center for drilling but also to help break the bond as mentioned previously. b) heat the stud, preferably to point of just beginning to turn red then remove the heat and let cool. c) after cooling, repeat hitting the broken stud with the punch. Then, apply the penetrant for a couple of days as mentioned above. d) At this point, I also use the reverse drill bits making sure I stay in the middle of the stud. I also ream the hole as I drill so the bit does not bind so tight it cannot be removed if it breaks. The previous heating of the stud seems to soften the metal and make it easier to drill. I start with a smaller bit (about 1/8" and get progressively larger. I've found that about half the time, by the time I've almost finished drilling with the second bit, the stud drills itself out of the hole! I suspect the impact of the reverse drilling also helps free the stud. As Dave T. mentioned, it's a real pain to remove an Easy-Out that breaks in the process. I've heard that some machinists use a torque wrench to keep this from happening, but I've found the best way to prevent this is to repeat the heating and penetrant. I like "Knocker-Loose" but this is in no way a scientific conclusion. Dave T. is also correct in his concerns about damaging the Al block with a cutting torch. Had I not seen it done before attempting myself, and if it had not worked for me on several occasions, I would not believe it myself. Despite my success at removing the studs with this method, I'm not suggesting this method be attempted by someone not skilled with a torch, nor should this method be used prior to exhausting the other alternatives mentioned above. I've always used a small torch/tip, had done several on cast blocks before attempting the Al, and all but two with aluminum blocks were done on a bench, not on the car. In other words, consider this a method of last resort done by someone skilled with a torch, with the right equipment, and with the recognition that block damage is possible, particularly if done incorrectly. Hope this helps, Woody ____________________________________________________________________________________Building a website is a piece of cake. Yahoo! Small Business gives you all the tools to get online. http://smallbusiness.yahoo.com/webhosting To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/