Use Old HE Flange for Drill Jig?
 

I have a broken exhaust stud that I need to drill out. Any thoughts on cutting off the flange from the old heat exchanger and using that as a guide to drill out the stud. I have an 83 which uses the sleeves on the flange, so it would essentially be locked in place and centered like the guide tool. Any thoughts?

Sounds like worth trying. You may want to put a bolt in the opposite side to stabilize it if both sides are not broken. I would also think about inserting a bushing in the HE hole on the side you are going to drill and start with an undersized bit. Last suggestion, try to find reverse bits. As you get deep enough, it may have enough bite into the stud to back it out.

Hardened inserts
 

Sears sells a set of drill bit stops that slide over the drill and fasten with a set screw. The stops are made of a hardened steel and make a good insert for drilling a pilot hole. Good luck with your project!

the hole is too big to accurately guide the drill bit. it's ballpark at best.

Yes it can be done. I did it and it worked perfectly.

I made some guide pilots to make sure that you are centered and running straight. I tapped the one side for the appropriate bolt size to match the hole size in the flange. Then took two grade nine bolts and drilled a hole through the center of the bolts. One hole was a smaller diameter than the stud to give me a pilot hole in the stud to start the final drill in the proper line.

The first bolt was used to drill a smaller pilot hole in the broken stud so that you will get a perfect start with the final drill size. Then changed the bolt to the final size and drilled out the stud. It worked perfectly as I said before.

Doesn't Stomski Racing make a really cool kit just for this very purpose? John

Yes, but it costs $265. Someone on the board fabricates his own version for around $150. I'm waiting to hear back from him on how long it will take to get. I'm kind of in a rush.

having done this when installing SSI's and again on Heads that were redone but old studs were left in and then broke off.. I will assure you that the Christian made tool is the best money you will spend... and worth the wait...

I am waiting for my drill jig from Christian, which I will hopefully receive this week. One question, comes to mind as i think about the procedure in my head. How do I know how deep to drill?

Matt;

Remove one of the good studs and measure the depth. Then put tape or a stop on the bit allowing for the depth of the stud and whatever tool you have. Simple.

So I drill right down to the bottom of the stud, or do I hold back slightly to ensure I don't hit the bottom of the head?

Matt;

I put my stop to the bottom of the hole. I measured the strud and the hole. The stud engagement was shorter than the hole so I decided to go to the full depth of the hole ensuring that I would get 95% of the stud. Don't forget that the drill has a taper on the end and if the stud were at the bottom of the hole you could not drill through the stud all the way if your stop is at the bottom on the hole. You would have to go into the head by the depth of the taper on your drill bit to go through the stud. There is still plenty of meat in the head to do this so I would not worry about it to much.

Ok thanks. Last question...I hope. Do I need a left hand drill bit or can I do this with a regular one? I cant find a left hand bit locally.

No more than 7/8" deep........
 

Matt,

I used 7/8" to 1" depth for the exhaust studs. I would suggest to use a 7/8" depth-guide for replacing broken or worn out exhaust studs. Do you still need the exhaust stud jig? I'll lend my set to you provided I get it back (and it's not for sale). Last time I lend it to a member from CA, he gave me a deposit more than the value of the jig. The first jig I had was never returned to me by a fellow member. So you know how I feel about losing a second one. PM me if you are comfortable with the arrangement.

Tony

thanks tony. I should have my jig from Christian hopefully today or tomorrow.

I recommend not using an "easy out" after you drill the stud. Mine broke off in the stud. What a nightmare to grind away the "easy"out with a dremel and not ruin the head. Engine still in the car and on jack stands, lots of bad words!.

Yes. I read enough nightmare posts to stay away from the easy out. Unfortunately, my drilll jig did not arrive today. Hopefully tomorrow, as my project is currently on hold until I get this tool.

I received my tool from Chris today. So I started drilling. I drilled out the stud and this is what I'm left with. I cant tell if I still have pieces of the stud in there or do I need to run a tap through it.

http://forums.pelicanparts.com/uploa...1319765856.jpg

You need to pick out and/or unwind the remaining metal that is within the threads.

How? I pull at the strands that were loose, but can't see how to get the rest out.