The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Fuel Injector Clinic
Please Support Rix Racing

Broken exhaust manifold studs.

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

@TDC

10+ Year Contributor
456
13
Sep 10, 2012
Nor-Cal, California
Hey guys I have a big problem!! I had an exhaust mani stud break off in my head. So I drilled a hole and used an easy out. The worst possible thing went wrong. the easy out broke off in the stud. So basically I now have a broken stud with a broken easy out in the center. :banghead: How on earth would I go about drilling out the whole stud and easy out? I'm already sure i'm just gonna have to helicoil it. What size helicoil kit would I need to get this done? What kind of drill bit would get the job done? Heres a picture of what I got. :ohdamn:

You must be logged in to view this image or video.


You must be logged in to view this image or video.
 
You will probably be able to drill through the extractor with a carbide drill bit and try again with another extractor, if not then drill the entire hole bigger and using a helicoil is an option. The helicoil size you need is m8x1.25.
 
I've been drilling with a cobalt drill but for the last hour and a half and it doesn't even look like the extractor is even being drilled into! This thing is really starting to piss me off! :/
 
Just for future reference this is what I use to extract broken off studs and whatever else.
You must be logged in to view this image or video.

You must be logged in to view this image or video.


It is going to be a PITA to drill through that easy out good luck.
 
Just for future reference this is what I use to extract broken off studs and whatever else.
You must be logged in to view this image or video.

You must be logged in to view this image or video.


It is going to be a PITA to drill through that easy out good luck.

Yeah im pretty screwed!! I have no idea how I'm gonna drill through it! I might just put it all together with that one bolt missing and then take it to a machine shop and just take off the manifold off to expose the bolt hole!
 
You need to get a carbide drill bit, cobalt drill won't work. I use left-hand bits when drilling out studs.
 
might want to reduce the drill speed .. many people* make the mistake of attacking the stud with the drill at full power,overheating the drill bits and causing frustration.

get a new bit,and take it easy .

* i too used to do it the hard way.
 
You need to get a carbide drill bit, cobalt drill won't work. I use left-hand bits when drilling out studs.

I will definitely give that a try before I start assembling everything.

might want to reduce the drill speed .. many people* make the mistake of attacking the stud with the drill at full power,overheating the drill bits and causing frustration.

get a new bit,and take it easy .

* i too used to do it the hard way.

Thank you sir! I did try to take it slow but that steel extractor is just so dang hard.




I've read that some people take a punch and attempt to drill the sides of the extractor with a very small drill bit. They say that if you drill around the entire broken extractor stud then you can take the punch and lightly tap around until the extractor gets some wiggle room. Not sure of this will even work let alone be safe for the cylinder head. What do you guys think??
 
I will definitely give that a try before I start assembling everything.



Thank you sir! I did try to take it slow but that steel extractor is just so dang hard.




I've read that some people take a punch and attempt to drill the sides of the extractor with a very small drill bit. They say that if you drill around the entire broken extractor stud then you can take the punch and lightly tap around until the extractor gets some wiggle room. Not sure of this will even work let alone be safe for the cylinder head. What do you guys think??

Ive never heard of that but I think if you just take your time, use low speed and the right bit you will get through the easy out.
 
Ive never heard of that but I think if you just take your time, use low speed and the right bit you will get through the easy out.

I just came back in after working on it. I have been drilling for almost 2 hours. Slow speed light pressure with cobalt bits. I'm using a punch to hit the extractor (controlled single hits) and it seems to be chipping off more of the extractor than the drill takes out. After a couple nicks are chipped off I go back through with the drill to try and even it out for more punching. After yesterday I had to take a different approach. Id have to say this job is testing my patients more than any previous job I've ever done!
 
Like said above, that you will have a very hard time with a cobalt bit. Cobalt bits are for annealed, ready to work with, steel. The extractor that is in there is hardened steel and very brittle (hence the reason in broke off). A carbide bit is what you will need to use to bite into that extractor. But BE CAREFUL, as carbide bits are also brittle.
 
Like said above, that you will have a very hard time with a cobalt bit. Cobalt bits are for annealed, ready to work with, steel. The extractor that is in there is hardened steel and very brittle (hence the reason in broke off). A carbide bit is what you will need to use to bite into that extractor. But BE CAREFUL, as carbide bits are also brittle.

Can you post a picture or link of the ideal carbide bit that I should use?
 
So far all these options are good. I stay away from easy outs. I operate a machine shop (small job shop) I tell everyone to bring it in before they break a easy out off. Why, because easy outs break well, easy. Usually drill a pilot on center then try a left hand drill bit. The pilot will actually let the left hand bit dig into the metal with a bigger bite which means more force on backing out before the bit breaks a chip. Or drill out on center with tap drill size and pick threads out. Also even on a bolt slightly below surface weld a tit up above surface and vise grips to remove. When welding use a spot weld then right as it goes from red to dull hit it again until you have it built up enough.
I stripped out a exhaust stud few years ago and pulled bolt and threads out and drilled and tapped for next metric size. Its a odd ball head now but didnt have to take anything off or out of the way to get it done.
Good luck
 
So far all these options are good. I stay away from easy outs. I operate a machine shop (small job shop) I tell everyone to bring it in before they break a easy out off. Why, because easy outs break well, easy. Usually drill a pilot on center then try a left hand drill bit. The pilot will actually let the left hand bit dig into the metal with a bigger bite which means more force on backing out before the bit breaks a chip. Or drill out on center with tap drill size and pick threads out. Also even on a bolt slightly below surface weld a tit up above surface and vise grips to remove. When welding use a spot weld then right as it goes from red to dull hit it again until you have it built up enough.
I stripped out a exhaust stud few years ago and pulled bolt and threads out and drilled and tapped for next metric size. Its a odd ball head now but didnt have to take anything off or out of the way to get it done.
Good luck

Thanks for the help! I have been just chipping away the extractor little by little and using the drill after to try and get it to drill through. So far it looks crappy but I can see some progress. The extractor is grinding down a bit. I think a couple more days of this process will get the extractor drilled down to nothing. Hopefully I can just helicoil using the same size after its done. Heres a pic. Again I know its not the best job but its getting there!

You must be logged in to view this image or video.


You must be logged in to view this image or video.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top