Big exhaust stud problem. What would you do?

[rs6er]

After acquiring SSIs an spending 2 weeks with heat and PB Blaster to no avail, I took my car to a muffler place with a good reputation. They told me they would have no problem removing my old exchangers and installing new OEM studs I provided, by welding nuts onto the old studs to get them out. After leaving my car there today I called to see if it was ready. They said they were having a hard time so I went over to look. On the left bank they had installed 3 of my studs by freehand drilling. The 3 new studs are on 2 ports and they are not straight. On the third port, both of the studs are broken off below the head surface. On the right bank one of the ports has one twisted and one straight old stud, and on the other 2 ports there is at least one good stud on each.

My inclination is to:
1) Get the tool from Christian to drill what I can.
2) Where the studs have been drilled slightly cockeyed (they said they can bend them if they have to!) I'm guessing they should be removed, redrilled with Christian's tool and then helicoiled.
3) As I understand it, Christian's tool needs at least one stud protruding from the head to work. What do I do with the port with 2 studs broken below the surface of the head?

HELP!

[Zeke]

"They told me they would have no problem removing my old exchangers and installing new OEM studs......."

Well, unfortunately there are plenty of idiots that will tell you something like that and then get themselves in the mess they are in. If it were my car, I would teach them a lesson not forgotten soon. I would call the flatbed, send the car to the best Porsche shop around, pull the motor, remove heads, send them to the machine shop..... you get the idea. And send the bill back to muffler man with a polite letter from your attorney.

Again, unfortunately, the muffler man could probably get his insurance company to pay. No lesson learned there. But I'll be damned if I'd take that car back on the street without the proper work being done. I'm not saying the drilling tool isn't a good tool. But why should you have to do that kind of work? Even Mr. Quiet Boom says it's not a real easy task, it's just a lot more doable thanks to him. He's probably talking one or two.....not both sides of the thing.

[rs6er]

Sounds great. I might actually get paid 10 years from now, if I'm lucky. This isn't Midas. It's a local shop.

[Zeke]

If this were in CA, it wouldn't take 10 years. And, I rather sue a small shop than Midas. I'm sure Midas has plenty of attorney power. But, in CA and in NY, I suspect, shops are governed by the state. Again, if it were me, I'd put the whole thing on my credit card (probably one with no balance) and just send the bill to them each month. They can watch the interest accrue all they want or can stand until you attach their bank account.

Hey, it's your car, but you asked, "What would you do?" So, I told you.

[A Quiet Boom]

John,


Very nice to speak to you on the phone. I thought I'd reply here so that others may benefit. If the crooked studs are too bad you'll need to remove them and replace with timeserts. Also you've got a 50/50 shot at lining up properly on the head with both studs broken. If you drill a little to one side or the other you'll need to timesert those holes as well.

The timeserts kit you'll need is Part No. 1812, which comes with 5 carbon steel inserts, drill bit, counter bore, tap, and installation tool. I'd get a few extra inserts as well, Part No. 18121. Here is the timesert page: http://www.timesert.com/html/mtrcsert.html

To do this properly I need to make the modified version of my tool which has three removeable bushings. This includes one standard 17/64" bushing for drilling out the center of the studs, a bushing for the timesert drill bit, and a bushing for the timesert tap. This setup is available as a custom order. As we discussed over the phone I will try to get one out tommorrow if you call me in time.

[A Quiet Boom]

Originally posted by milt
[B
Even Mr. Quiet Boom says it's not a real easy task, it's just a lot more doable thanks to him. He's probably talking one or two.....not both sides of the thing. [/B]

Mr. Boom, LOL

I have done both sides of a car, I did bell's 3.2 on an engine stand and it was actually harder since I had no leverage to push on the drill. The key to successfully drilling steel is low speed with a lot of pressure, most guys spin the drill at full speed and burn up bits. When I did bell's car I snapped a drill bit on the second stud, I removed it and finished that hole and the other ten with the a new bit. The new bit was still sharp when I was done. When my motor comes out this fall I'll be drilling all the studs and replacing them. It's actually not a bad job IF you take your time and drill properly as well as clean the head surface so the tool sits flat on the head.

If it where my car in the middle of driving season I'd just fix it and then fight with the muffler shop. If it where over the winter I might consider your suggestion of tearing the motor down. The problem is out-laying all that cash hoping to win a suit against the muffler shop. I'd more likely bill the shop for the cost of the tool and parts as well as my time at their hourly rate. Obviously these mechanics weren't thinking, why would they call before taking a drill to the heads of a 911? They said they would take the studs out by welding nuts on them and then turn around a drill the ones they broke, bad judgement call IMO.

[Zeke]

I agree with almost everything you say, Christian. If he asked "what should I do," I might have had a different answer closer to yours. Oh, I know, it's just a matter of semantics. But, there is one problem, courts don't usually recognize your own personal labor just as the IRS won't. So, if you want compensation, you have to hire someone, pay a bill and submit the bill for consideration.

Lastly, I may have underestimated your fine tool. I read your threads where you were having a little difficulty and I took that to mean that this is a good tool given the ability to drill and replace studs while the motor was still in the car. Now, with studs apparently installed incorrectly in this particular situation, I just wouldn't be prone to accept anything but a first class job in a machine shop. If your tool duplicates that environment, then I better get one because the machine shop already has enough of my money.

[A Quiet Boom]

Milt,

I wouldn't say machine shop quality but pretty darn close if the user takes their time and follows directions. The tool is essentially a jig that allows one to drill a concentric hole in the correct place. However the accuracy depends on how well the head surface is cleaned up and whether or not the user makes sure it's sitting flat on the head. I like to tap it into place with a mallet. Given the alternative of removing the engine and tearing it down then sending the heads to a machine shop where they might be 0.003-0.008" more accurate jsut doesn't seem worth it unless the engine is already apart. Besides if I where being paid to drill the studs on my manual mill I'd charge more than I sell these tools for. After all each head needs to be fixtured up on the mill table, the stud centers indicated in then drilled. I'd bet the machine shop time would be equal to the time taken to do it yourself. The setup with the alternate bushings for the timeserts will do a fine job of placing a timesert right where the factory threads where.

All in all the decision is John's. I'd jsut hate to see hime tear down a good running motor in the hopes that he gets reimbursed in the end.