Does anyone sell a fixture for drilling broken exhaust studs

[89turbocabmike]

Originally posted by john walker's workshop
when you do that with exhaust studs, 9 out of 10 will just shear off below the welded nut. if only life was so simple.

Exactly what happened to me John. Turbo heads with 100K on them and original studs = Trouble ! There is nothing more frustrating then being stumped with this problem when you have 3 welders and a garage full of tools.

With Christian's tool I no longer fear the exhaust stud! Bring 'em on!

[A Quiet Boom]

Thanks Mike although I need to give credit where credit is due. The tools I make are simply a production version of the tool John Walker had made by hand by a machinist, he was instrumental in helping me bring this tool to market by providing advice, actual port measurements and his experience using his tool in his professional shop. Without John's help I doubt I'd have thought of such a tool much less find a bunch of different heads to measure.

Just so everyone knows I've sold out my original batch and will be making a new batch this weekend. The new batch has extra clearence designed in at the CNC stage. The last batch I had to clearance on my manual mill after finding out they didn't fit certain heads. I have one tool that has to go out Monday and will have others ready by Tuesday. Even with a CNC mill these tools are very time consuming, especially the disks since they are a two step process and have to be finish one at a time. Here is a link to the new listing if anyone is interested:

http://cgi.ebay.com/ebaymotors/Porsche-911-broken-exhaust-stud-removal-tool_W0QQitemZ4596506108QQcategoryZ35625QQrdZ1QQcm dZViewItem

[Vin-barrett]

This question kinda sounds silly but about how many of the studs normally break when doing both exchangers? (Being careful and working with MAPP gas)

I've ordered 5 from our host.
Am I being optomistic?

Christian - I just received your beautiful tool (ebay) a couple days ago. Thank You

[aircooledsonly]

I use my MIG welder,weld a nut to the broken stud,this heats the cyl head,wait 30 sec ,apply socket to unscrew. I have had a 90+% sucess rate on vw/porsche cyl heads in car,though it may take 2 to 3 tries jay(older than porsche #1)moore. contact me at 1-928-776-0163 or jmor.aco@hotmail.com

[john walker's workshop]

then you will need the tool for the rest.

[A Quiet Boom]

Vin,

Glad to her you recieved the tool and are happy with it.

Jay,

I'm not certain I understand your motives here, perhaps you doubt John Walker's excellent credentials? Maybe you think I'm some sort of jerk for providing a useful tool to other enthusiast's? Whatever the motive it sure doesn't seem like a friendly way to introduce yourself on this BBS. Have a nice day.

[Asjac]

Is it true that you have to peck the tool onto the head to make sure you have a correct line-up? If so, how do you get the tool off the head, by prying?

[A Quiet Boom]

The tool is a tight fit into the port, it has to be to ensure proper alignment. Cleaning the carbon out of the port and any rust of the good stud helps as does putting some anti-sieze or grease in the port and on the stud. That said it's important to use a disk that fits your head snugly but not too tight, the tool includes 8 disks to suit most 911's and several are very close in size. Mike (89turbocabmike) found he had to work a little to get the tool off the first port he did, on the second he cleaned out the carbon and the stud and used antisieze and the tool came off much easier. Perhaps he can comment more than I on this. You can see the results of how well the tool works with a tight fit on the previous page. Mike was able to pull the threads out in one piece! Now that won't always happen but it does show how accurately the tool centers the bit over the broken stud and keeps it concentric to the studs axis.

Just a note, I have one tool to ship on Monday and then I need to rebuild my inventory so I can't ship anymore until weds or thurs. I've got another job to finish this weekend before I can make more tools.

[Asjac]

I was just wondering because I saw a tapped hole on the other tool, the one with the set screws, and it looked like it would allow you to put a bolt in there to help you get it off the head. I don't know if putting a set of these "removal screw" holes would be advisable, if they would fit, or if they are even needed.

[89turbocabmike]

On my first stud repair I had problems removing the tool when finished. This was in part due to the fact that I didn't use any lubricant and my one good stud had quite a bit of corrosion on it. I had cleaned the exhaust port of carbon so that didn't exacerbate the problem but Christian's tool fits tight like it should, so with the rust on the stud I actually used some light taps with a hammer to get it seated. I obviously wasn't thinking ahead! To remove the stuck tool I fabricated a small slide hammer with 1/4 nut on the end and attached it to the bolt holding the insert in the tool(luckily I had assembled it with the nut showing) This worked though it obviously is not the most ideal place to pull from. I think that a threaded hole between the centerline of the insert and the good stud would provide a more ideal location to pull from. The second stud I repaired I made sure to clean the body of the good stud with my dremel's wire brush AND used some antiseize both on the stud and the insert. Removal was much easier using just channel-locks gripping the main body.

Let me take this moment to extend my thanks also to John Walker for his help in designing this tool as well as all his contributions to the Board. Thanks John

[A Quiet Boom]

Mike,

I've taken your suggestion for the tapped hole and will incorporate a 3/8 tapped hole right where you suggested. Them all one would need is about a 6-8" 3/8" bolt with a weight on it to act as a mini slide hammer. I'm also going to tap the center hole the same so that the same bolt could be used to push tight disks out of the tool. Thanks for the suggestion.

BTW, I was down for a few days with what I thought was a broken mill, turns out it was minor but at this time I am out of tools until Sun. or Mon. so if anyone orders from ebay there will be a small delay.

[Porschephd]

I have seen all sorts of gadgets in the industry and have paid a ton of money for tools and continue to do so. When I ordered this piece I really had no idea what to expect. When I got it I was even more baffled with what the hell all these disc were for. I then read the instructions and started the procedure that would hopefully save me time and my customer money from a tear down. 3 hours later I had repaired 5 broken studs. Yes 5!!

I hardly ever endorse anything and I am openly and publicly endorsing this tool. I would have paid 10 times the amount. In fact the only displeasure I have is this was not around 15 years ago when I started playing with Porsches. I have literally had to pull a new motor down because of a broken stud and um, a easy out. This was the first experience with studs 15 years ago. I have hated them ever since. Since then I normally will not screw around and with this many I simply pull the heads. Normally there is no way to accurately cut the holes back in place on the car. When I cut the holes I removed the tool and unspiraled what was left of the stud. It simply had been cut to a string of metal like a Heli-coil.

I am not selling these nor work for Christian, just one hell of a happy customer!!! Thank you sir!!

[A Quiet Boom]

Thanks for the kudos Stephan, I'm just glad these work so well. I've only had one serious complaint on these. I sent the guy a new tool and I'm awaiting the old one back, I think I sent him a prototype or something by accident. All the feedback I've gotten has gone into making these tools even better. Like the tapped hole, I made a disk that was real tight in one of my bench heads, so tight I had to tap the tool in with a hammer. I screwed in an 8" 3/8" bolt with a weight on it like a slide hammer and the tool popped right out.

Guys just a reminder, use carbide bits and lots of cutting oil. I'd include bits with the tool but I can't buy them wholesale so you'd have to pay more than you can buy them for. I like Tap Magic thread cutting fluid, pricey but works good when there's lots of drilling to do. Also carbide likes speed and pressure if it's well lubed/cooled with fluid.

[A Quiet Boom]

Just an update as I've sold a few of these lately. I'd simplified things somewhat. The current tool comes with 8 aluminum disks, I did this to lessen cutting tool wear and thereby increase accuracy. All the new tools have the tapped hole to assist removal.

I recently made a tool for use with Big-Certs from timecert to repair a set of head previously repaired with helicoils. This tool required a much larger drill bushing, a tap bushing, and a set screw to hold the bushings since they are not press fit like the standard tool. Email me for details of this option if interested. It's best to contact me at rsr911@neo.rr.com since that's my primary account for 911 and machining stuff.

Now if I can just track down that misfire in my own car I'll go for a drive......

[bell]

christian recently made me a set of block off plates to seal the intake/exhaust ports for a thorough cleaning of the engine (to keep water/etc/out of the cylinders).
i'll be starting a new thread next week after i hit it with the pressure washer to show how they worked, looks very promising

[A Quiet Boom]

Hey don't I get to play in the water?

Actually I'll make these in sets of 6 out of 1/4" aluminum if you guys are interested. The blockoff's fit both the exhaust and intake (same stud sie and spacing).

Drove the car today, just had to adjust the freshly rebuilt carbs some. Now a little work on the clutch and I'll be happy.

[A Quiet Boom]

Finally got my hands on a 3.6 head thanks to another Pelican so I could design and build a tool for these engines. This one locates off the O-ring groove machined into the head. The 3.6's have rough cast ports unsuitable for locating with a port disk but since the groove is machined in, presumably on the same CNC than drills and taps the stud holes it's a great way to locate the drill bushing. I've got 3 available until I get another metal order in. As for the standard tool I've got plenty of those although I'll need to make more port disks in the coming weeks.

[shoguneagle]

Excellent article/thread showing how and need for such a tool. I think I need this since I have two brokn studs. Thanks for the info and for developing tooling.

Steve Hurt

[NathanUK]

Christian, do you make your tool for the 3.2 carrera & the 3.3 930?

[A Quiet Boom]

Nathan,

The current tool fits all 911 2.0-3.3 turbo. There are a few special heads I may not have port disks for but I can make those to order with measurements. I also have a tool for the 3.6L.