Dilavar again

[SWISSMADE]

Ok, this is hardly a new thread but I haven't found a definite answer up till now. Here's the storyline.....

11 of the devil's own Dilavars came out either willingly or unwillingly (patience pays apparently) and then number 12 decided it liked it just fine where it was, dug in it's feet and let the rest of it's body go free In other words, it snapped right at the cylinder base . There's not enough stud left to weld a nut to or to grip in any way, EDM is not available in my neck of the woods neither is a machine shop worthy of the name. Soooo, I guess the buck has stopped here at my doorstep and it's out with the trusty hand drill once again. Question for all you experienced 911 fans out there:

What type of drill bit will eat the heart out of this awful alloy and how should I attack it?

Cheers, Mike

911sc 3.0

[tab tanner]

Get the best drill bit you can find, Snap-on make some of the best! also use a splined ez-out to get ahold of the stud. Once again snap-on makes this. I looks like a input shaft of a transmission but just much smaller with a collar to turn it out I think the set is in the $40-50 dollar range. USE some heat when you are trying to back it out
Best of luck

[SWISSMADE]

Thanks Tab, keep you posted,

Mike.

[Kevin Taylor]

Interesting Thread you started here. I also have the same issue
to deal with. I will follow this one closely.


Money can buy happiness..............Buy a Porsche

K.T.
1973 911 E 2.4 MFI
1983 911 SC
1978 911 SC
1965 Devin "D" - 1967 912 Power Plant

[mb911]

same thing happened to me. I took the TIG welder with some 308l ss filler and built the stud back up high enough to get a nut welded to it. after that it came right back out. worked well. Way better then a drill.

[Kevin Taylor]

mB911 Very creative. Never thought of that. I will go see my
welding friend. Thanks K.T.

Money can buy happiness..............Buy a Porsche

K.T.
1973 911 E 2.4 MFI
1983 911 SC
1978 911 SC
1965 Devin "D" - 1967/ 912 Power Plant

[SWISSMADE]

Great stuff guys, keep the solutions rolling in.

Mike

[sjf911]

Lots of heat (MAP/O2 or hotter). Welding it up makes a lot of sense as the intense heat will really help.

[dyhunter]

I had an exhaust stud break off a couple years ago. If you decide to go with drilling and an eazy-out try to find a left hand twist bit. Also make sure to get the real eazy-outs and not some off brand, the latter break alot easier.

[Porsche_monkey]

If it were a 2.7 I would say get case-savers, but since you have a 3.0 that is unnecessary.

Make a drill jig using the other three stud holes, insert a drill bushing into the jig and drill it out with a solid carbide drill bit. Should be easy.

If you thinking of drilling it out by hand I would recommend you not do that, this is a valuable case and you could wreck it, or at the very least end up sending it out for case-savers. If you do not have the right tools send it to a machine shop. They will set it up square on a mill, find the center and bore it out properly. All for an hours labor.

[cashflyer]

I do NOT use the spiral flute ez-outs that are readily available everywhere. I've had very bad luck with them against fasteners that are really, really STUCK. And if it snaps off in the stud, you now have a hardened chunk of metal that you will almost never be able to drill out.

Good


Good


Good


NOT good.


As a spiral flute extractor bites harder into the broken fastener, it tends to expand the fastener. This increases the force needed to remove the fastener, and in turn can cause the extractor to snap off under the excessive force.

[tab tanner]

The 3rd one down it the one I use

[fastfredracing]

I had also purchased a drill bit centering kit from snap on , that allows one to perfectly drill in the center of the bolt , eliminating any possible damage to the threads, this a great tool, and has saved my arse more than once.

[DUK]

Tig weld a nut on like Ben said. Or if you can't do that use a left hand drill bit set, start small and work your way up. If you get close to the thread size and it still isn't out heat the area around the stud and melt some parafin wax on it and use one of the afformentioned extractors. And as said before patience is a must.

[SWISSMADE]

Hi everyone, thanks for all the suggestions. I decided to go with Tab's solution (Stahlwille extractor.... $150 ) and lots of heat.

Here is the result after starting two hours and two drill bits ago.... a mere dimple in the end of the stud

I guess I'm using the wrong drill bit. Any metallurgists out there?

Mike.

[DavErb]

As PBH said make up a drill jig using the other three stud holes to hold the bit in place right over the center of the stud. Unless the picture is distorted you are already off center and starting to eat into the case. Take the time to do it right or you'll have a bigger problem than you've already got

[Porsche_monkey]

Buy a solid carbide drill bit, not a carbide concrete bit, the drill bit should be made entirely from carbide.

[mb911]

weld a nut on there. that was as bad as the one I had and it came right out. the drill bit is a 50/50 at least you can drill if the welding does not work

[dweymer]

any update..what worked?

Also,
Can someone explain how the straight fluted extractors work, I need some good ones, as the spiral ones helped me ruin a carb body

[cashflyer]

And here is one more type of straight fluted screw extractor:


How they work:
Drill an appropriate hole into the broken stud or bolt. The drill size required is usually stamped on the shank of the extractor. If not, you may need a chart from the manufacturer.

Once the hole is drilled, place the end of the extractor into the hole and give a light tap with a hammer to seat the flutes into the metal. Place a wrench or t-handle onto the extractor and turn. A t-handle is always preferred as it places a more even turning moment on the extractor, however space constraints may not allow it. You can also use a square socket with a ratchet to turn the extractor.