I am in Broken stud / EZOut hell and need some advice.
 

Hi,
First of all, I will admit up front that I naively thought I was going to reuse the head studs on this '77 930 engine I'm rebuilding. I thought "It's a low mileage engine, no problem. They look like they're in good shape." http://www.pelicanparts.com/support/...sleephappy.gif


Now, with that out of the way, I have removed the heads again and extracted 23 of 24 studs (3 of which were broken).

The LAST broken stud is a stub in the case, with none sticking out(#6 lower, closest to flywheel). I have drilled to the proper size for an extractor. Actually, I first drilled to 5/32" and tried a #3 extractor, which twisted. Fortunately it didn't shear inside the hole.

Now I've gone to 1/4" for a #4 extractor, but the reverse spiral threads just won't bite into the stud.

So, is there a trick to making these things grip the dilavar material? How much downward pressure should I exert when inserting them, and how far in do they go?

Can you tell this is my first time at all this? Thanks for any advice!

Colin

Experience has taught me....There is nothing "E-Z" about E-Z Outs!

I hope you will find some Snap-On brand extractors.
They are the only type I have ever found to not break off.

One other thing to remember..... The studs are treated with a thread locking compound (aka: Loctite) at the factory. You have to heat the case near the stud bore to melt this stuff, otherwise your chances of removing the stud are not good.

I have used ez-outs for years in aviation. The best way to use them I have found is to clamp vise grips onto them and tap firmly with a hammer on the end of the extractor while turning the vise grips.

Good luck!
:p

A friend told me once that E-Z Outs were a tool for replacing a hard to drill out bolt with an impossible to drill out E- Z Out.
-Chris

Chris, I think your friend is right. Like Doug, I have been entrusted with the secred of screw extractors. The set of eight extractors like the one pictured above are vended from the SnapOn truck at about a $30 price. Perhaps the only really excellent bargain on the truck.

Still, that stud is going to be tough to extract. Doug is right about the heat. It takes A LOT of heat. Do a search.

Read the instructions with the screw extractor set. You gently tap it in, then turn it. I have had very good luck with them.

Check out this thread: Broken Stud

About half way down the thread, Wayne describes a rather remarkable broken stud removal process by a guy here in Southern California (Gardena, to be precise). If all else fails, ship it to him.

Good luck!

Colin/Cowtown, Doug is right, w/o proper amount of heat in correct place, your chances of removing stud/stub are exactly nil. If you have access to a good Porsche machine shop in your area, it would be the smartest $$ you've ever spent. I recommend Competition Engineering in Lake Isabella or German Precision. Also EBS in L.A. area. Short of that, do a search on this forum until you find the pictures that show where to heat the case, must be red hot , then it will come out w/ the right (snap-on) tool. Good luck. :cool:

See Project 97? I think in 101 Projects, if all else fails...

-Wayne

See the following link...it details my somewhat recent experience removing a broken exhaust stud.

http://forums.pelicanparts.com/porsche-911-technical-forum/87528-broken-exhaust-studs.html

The snap on part that I used is:

http://buy.snapon.com/catalog/pro_det.asp?tool=all&item%5FID=10418&group%5FID=12 54&group%5Fname=Combination+Extractor+Sets&sub%5Fc at%5FID=1317906&sub%5Fcat%5Fname=Extractor+Sets&ca t%5FID=1317769&cat%5Fname=Extractors&store=snapon% 2Dstore&dir=catalog

This broke. Then I went to http://www.truebite.com, bought their high speed bits, which could eat up the stud and the broken extractor with ease. Finally I had my mechanic finish drilling out the stud and heli-coil that cylinder.

getting an aluminum case RED HOT is not correct. it would melt way before that. you do have to heat the case in the cylinder bore, adjacent to where the threads are, with an oxy/aceteylene torch until the loctite softens and the stud begins to turn. the case is a big heat sink, so don't be afraid.

23 window
 

john:
what type of vehicle is the 23 window?

gary

Thanks everyone (once again) for your useful replies.

I'm not ready to wheel this thing out to the machine shop just yet-it would be a blow to my ego.
I will order a SnapOn extractor and give it a shot - stay tuned!

By the way, I'm currently planning on replacing these Dilavars with factory steel studs. This will not be a wild engine. It will run on pump gas at stock boost. Anything wrong with using the SS studs?

Thanks,
Colin

a 23 window is a VW BUS. Would hate to put seals in one if they cost any where near what porsche seals cost.