BOSS
05-28-2010, 11:28 PM
Came across this write up online for removing broken off exhaust manifold bolts. I guess you know what's about to go on in my garage :)
Credit to Chevyboy86 for posting this:
this is advice for all the guys in here with head and manifold issues, i used too work in a machine shop for 4 years...just a jobber shop whatever came thru the door pretty much...it was all old conventional machine tools, my boss was an older scottsman been machining for 40+years. i have taken ALOOOOT of broken studs, dowels, bolts out. shaved heads, exhaust manifolds. tons of engine machine work and re-work and re-machine, i.e. shaving heads exhaust manifolds, honing, port and polish jobs, boring...all different types of stuff.
im gonna go on a limb here cuz their is alot of questions asked in this thread.
1.the "fastest" way too get broken studs out is too weld a nut of bolt too them, if they are above the surface...BUT if you are working with aluminum...this can really create problems, sometimes the heat tends too bind the materials together even tighter resulting in pulling the threads out with the stud when it comes or "mashing" them up. the "safest" way too get the threads out (and i realize you cant sometims do this cuz you still got the motor or part still on the truck or you dont got the tooling) is too grind the broken peice flat if you can, center punch it as close too the middle as possible, just start with a prick punch and you can move it around. once you are satisfied take a center punch and givver a good wack. then start drilling, start with a small drill first (pilot hole) just too make sure of your depth if its a blind hole. then if you have access too a left hand twist drill they work exceptional, most of the time uhoh.gif . if that doesnt work, go until you are at the tap drill size in steps, by this time you should be able too see the crests of the female thread. take a tap, i like too use a "starter spiral machine tap" cuz they arent as brittle, and the spiral flute design really helps you pull the threads out one at a time. once you are done the thread is usually like new unless it was stuck in the first place because some other yahoo before ****ed it up already. thats the way i prefer, especially if its a newer part, and its off of some dudes hot rod than im really carefull with it. i tend too stay away from easy-outs, they can be a nightmare. they are made of a type of high speed steel, they like too break. once you break one off in a hole its a real chore too get them out. usually gotta drill them out with carbide. seems like a lengthy process but its the safest way of doing it welding is fast but its risky...if you got the part out a machine shop should be able too do it for you in no time. alot faster than watching a mechanic doing a machinist job rolleyes.gif (gonna get chewed for that one haha).
2. warped heads or exhaust mani's - again no matter what, ive seen heads come off that were farely new and they were out about .005" - .010". its not a big deal for a machinist too take a little skim off a head for you. old ones ive seen just completely screwed too no return. exhaust manifolds are the same most of the time they are out so much its not even worth it. just buy new ones but its worth bringin them down too a local machine shop too see how bad they really are. cuz if they arent bad it might only take an hour max too take a little skim cut or as one guy said get it surface ground. it all depends on how cheap you are HAHAHAHA.
bringing your parts into a machine shop isnt gonna hurt your wallet by any means its worth a try, they might be able too fix something for you that would have taken hours and write a new curse word bible in a couple minutes with no fuss and a cheap fix. just for all you guys imput. just make sure you get a written estimate!!!!!!!!
BOSS
Credit to Chevyboy86 for posting this:
this is advice for all the guys in here with head and manifold issues, i used too work in a machine shop for 4 years...just a jobber shop whatever came thru the door pretty much...it was all old conventional machine tools, my boss was an older scottsman been machining for 40+years. i have taken ALOOOOT of broken studs, dowels, bolts out. shaved heads, exhaust manifolds. tons of engine machine work and re-work and re-machine, i.e. shaving heads exhaust manifolds, honing, port and polish jobs, boring...all different types of stuff.
im gonna go on a limb here cuz their is alot of questions asked in this thread.
1.the "fastest" way too get broken studs out is too weld a nut of bolt too them, if they are above the surface...BUT if you are working with aluminum...this can really create problems, sometimes the heat tends too bind the materials together even tighter resulting in pulling the threads out with the stud when it comes or "mashing" them up. the "safest" way too get the threads out (and i realize you cant sometims do this cuz you still got the motor or part still on the truck or you dont got the tooling) is too grind the broken peice flat if you can, center punch it as close too the middle as possible, just start with a prick punch and you can move it around. once you are satisfied take a center punch and givver a good wack. then start drilling, start with a small drill first (pilot hole) just too make sure of your depth if its a blind hole. then if you have access too a left hand twist drill they work exceptional, most of the time uhoh.gif . if that doesnt work, go until you are at the tap drill size in steps, by this time you should be able too see the crests of the female thread. take a tap, i like too use a "starter spiral machine tap" cuz they arent as brittle, and the spiral flute design really helps you pull the threads out one at a time. once you are done the thread is usually like new unless it was stuck in the first place because some other yahoo before ****ed it up already. thats the way i prefer, especially if its a newer part, and its off of some dudes hot rod than im really carefull with it. i tend too stay away from easy-outs, they can be a nightmare. they are made of a type of high speed steel, they like too break. once you break one off in a hole its a real chore too get them out. usually gotta drill them out with carbide. seems like a lengthy process but its the safest way of doing it welding is fast but its risky...if you got the part out a machine shop should be able too do it for you in no time. alot faster than watching a mechanic doing a machinist job rolleyes.gif (gonna get chewed for that one haha).
2. warped heads or exhaust mani's - again no matter what, ive seen heads come off that were farely new and they were out about .005" - .010". its not a big deal for a machinist too take a little skim off a head for you. old ones ive seen just completely screwed too no return. exhaust manifolds are the same most of the time they are out so much its not even worth it. just buy new ones but its worth bringin them down too a local machine shop too see how bad they really are. cuz if they arent bad it might only take an hour max too take a little skim cut or as one guy said get it surface ground. it all depends on how cheap you are HAHAHAHA.
bringing your parts into a machine shop isnt gonna hurt your wallet by any means its worth a try, they might be able too fix something for you that would have taken hours and write a new curse word bible in a couple minutes with no fuss and a cheap fix. just for all you guys imput. just make sure you get a written estimate!!!!!!!!
BOSS