just bill

It finally happened, after 8 exhaust valves, 8 valve guides, 2 intake valves all that cleaning, not to mention having to remove the heads to have them checked fot the proper fit for the regulator and finally the last thing was to extract the broken valve cover lower bolt, drilled the hole in the broken bolt then that subtile little cracking sound was heard- the extractor broke.The machine shop was not to convincing with there answer since they said the extractor was case hardened. Any suggestions??

Thanking you in advance

Just Bill

JEC_31

Did YOU snap the extractor or did the shop?

If the shop snapped it then that's THEIR problem. Either they get their broken piece out of your head by hook or by crook - or they replace your head gratis with one that does not have a friggin extractor tip jammed in it.

If you snapped it then... uh oh.

Let me ask my machinist friend. BRB.

JEC_31

No problem.

Tactic A) With a nice hammer and ***** punch, carefully attempt to tip-tap on the broken extractor laterally to try and unscrew it out (remember the Lefty thread LOL).

Tactic B) Have the shop set it up on the mill and carefully mill out the extractor AND the broken bolt with a carbide end mill. Screw the "case hardened" excuse, carbide will eat it for breakfast. Then extract the remains. Done right, you won't even need to re-tap the threads in the hole.

Imo000

Ehhhh I feel your pain! Happend to a buddy of mine and took him many hours and about a dozen of titanium drills to drill it out. I broke one in the past too and since then I'm staying away from them.

There were discussion on using extractors and pretty much everyone suggest to stay away from the thin ones. As a DIY guy, there is nothing worse than a broken extractor.

Imo000

This is usually true but in this case the hole is only 6mm so even with a carbide end mill there is a really good chance that it will snap. If thye can pull it off without damaging the treads, I'll be amazed.

JEC_31

6 mm is pretty freakin' small, granted. But my machinist buddy thinks he can do it.

Just Bill! Where are you located? We're in Grand Rapids, Michigan.

GregBBRD

Go buy yourself a Dremel tool and a carbide bit for cutting out tile grout. 1/8" is the best one. These babies are harder than anything I've ever seen and will generally eat right through an extractor....they will end plunge right though it. Continue to use this tool to remove the majority of the broken bolt, until there are just the threads left. Generally, at this point, you can get the remaining steel pieces out.

Install an insert.

Use the updated hardware. I assume you are working on an '85/'86.

JEC_31

Good tip on the 1/8" carbide tile grout bit, Greg. I'll remember that one.

I wonder if Just Bill checked the e-mail notification box when he started the thread?

Bill Ball

NEVER AGAIN USE EXTRACTORS! Yes, I learned the hard way. Use left hand drill bits, available from HF, among others.

To get the extractor out, the best tool is a DREMEL diamond-tipped point. They make packs with a couple of different sized ball tips. Cost $5-10. Try Dremel 7103. I usually buy Dremel 7150. They are the only thing that will cut through the extractor. The extractor is tungsten carbide, so a carbide bit will not work. Use the diamond point to cut into the extractor a little bit at a time, no more than 30 seconds with light-moderate pressure. Do not let the tip glow red or it will pop off the shaft. So, have a spare bit or two if you do.

If the head is off the car, you can have the extractor removed by electro dissolution. Look up "tap removal" in the yellow pages. The process is called EDM (electrical discharge machining), designed to dissolve ferrous metal. There is a local shop in my area that will even make housecalls if the head is on the car. They charge $300 for a housecall. I had them scheduled for a visit when I managed to get my problem solved with the Dremel diamond-tipped bits in about 20 minutes.

just bill

Thanks, I started to use the Dremel last night, but I need to get one that is electric powered, my battery one will not keep up with the need.
I was the one who snapped the extractor. Bill you are sooooo right about extractors.
The head is off the car (again) I will buy some new toys tonight and let you guys know how the operation goes. Thanks again for the help.

bill

Bill Ball

Just Bill: Get a couple of packs of diamond-tipped bits for your Dremel and you will have this solved in no-time!

just bill

Thanks to all, the Dremel is working fine. The extractor is giving a lot of resistance, however it will end up a pile of very fine metal filings on the floor, eventually. I have had some limited experience with helicoils so when I install one there will be another challange to gain more wisdom from. However, I will definately approach that operation with the greatest amount of respect. The most important lesson gained is ask the "list" first, and even if the answer is JB WELD, then consider it as an option.

Thanks again,

just bill

Bill Ball

With very careful use of the tiny diamond bit, going across the extractor, you should be able to section it into thirds or quarters. That's how dentists remove wisdom teeth, although they crack them into sections. Then it should almost fall out. Then proceed to do the same with the bolt stub or use a left hand drill bit. In theory you are left with the original threads and no need for a Heli-coil. I understand it's not that easy. Also, extractors are a lot harder to remove than thread taps, as thread taps have flutes that serve as natural section starting points. Go slow. Be patient. Good luck!