Installing a new cylinder stud in GTR motor

[slawsonb]

I had removed the heads from my GTR to inspect the cylinders. While torquing the head nuts upon re-install one of the cylinder studs slowly separated (cyclic stress failure) despite carefully following the torque spec in the manual. It was one of the original thin profile studs still living in my 67 (year built) motor. No idea how many times its been through this process, but it hung on as long as it could and died a good death. Richard provided me with a new beefy one to replace it and now I am wondering what the best procedure is to install and achieve the proper stud torque. I am considering jamming two nuts together on the stud and using the upper most nut as the driver. If someone has a better plan, please waive me off. As usual, I'll appreciate any advice and counsel (and opportunites to procure new tools!)...thanks...

...bert

[ziggy stardust]

See page 38, service letters. There is some info there.

Z

[slawsonb]

Thanks for the pointer Z. That was actually my first foray into the service letters. I will be going back there, but that page addresses a stripped tapped hole in the engine case. Fortunately, my case is fine. I was able to extract the lower half of the broken stud without damage. My quandry is how to get a grip on the new stud to allow torquing to the proper spec (304-345 in-ibs). Just looking for some basic wrenching advice.
...bert

[BRT-GTR]

bert,
 Can't think in in-lbs, don't have a small torque wrench - must get one now I'm back into class engineering with a GTR. So divide by 12 = approx 26 ft-lbs, not a great torque for an 8mm stud. Your double nut arrangement should be fine, use some decent quality nuts, maybe borrow one of the exhaust flange nuts and put it on the top of a standard thickness nut. This will give you something sturdy to swing on.
If you don't fancy that idea, a garage friend of mine has got a special stud removal tool that looks like a drill chuck ( probably Snap-on make). I was horrified when he hand clamped it on to the threads of a difficult stud during a recent turbo renewal for me. The stud came out easily.  Don't know how it works but there were virtually no visible marks on the stud and I could hand screw a nut all the way down. I guess it would install studs as well, see if you can borrow something similar.
 Brian.

[reed]

bert,
With the old head stud out, i would run a tap down first then fit your new stud, and jamming two nuts together will work etc.
Good luck.
Steve.

[Bikenstein]

Use a bottom tap and make sure you blow it out after. With air

[slawsonb]

Thanks for the great advice all!
Steve, had already done the tap clean out step and thanks for confirming my nut idea. (seems like the only kind I have anymore)...
Bikenstein, thanks for the blow out step advice although I don't have a bottom tap that size.
Brian, appreciate the confirmation and stud remover idea. I expect the load (from the stud remover chuck) is distributed approximately uniformly around the thread (stud) so no localized stress to cause damage (if no slip).  You will definitely benefit from a small torque wrench.
...bert

[BS Mechanic]

This might be an excuse for another tool, take a look at this from Motion Pro:

http://www.motionpro.com/motorcycle/tools/category/stud_installation_tools/

[slawsonb]

Yessssssssssss! I knew there was a tool op in this! Thanks BS Mechanic...
I did a google search, but did not pick the right word combination, Should have thought of Motion Pro.
I bought their wheel bearing extractor at Steve Reed's recommendation. It works great, bet this does too...
Excellent!
...bert

[ziggy stardust]

For those who can't think in ins-lbs there is a free conversion app you can download onto your android phone or tab.

ConvertPad.

https://play.google.com/store/apps/details?id=com.mathpad.mobile.android.wt.unit&hl=en

Z

[BRT-GTR]

Guys,
Made a note of Motion Pro from other post somewhere. However , we don't all live in US, the postage on an 8mm stud tool($7.99)  is $6.50 within US. Have to phone or email for International postage , so that kills that then, will carry using using my teeth! . Here in 'Rip Off UK', I do envy the quality, choice and prices of services and tools etc that you have available in the US. Anyone adopt me?.
 I have a pair of war time pliers, electrician type,(got to be 70 years old) made by UTICA TOOLS, NY  that have cut hardened steel pins and been generally misused but they are still as good as the day they were made. Will still grip and pull out a small nail with only 1/32'' showing. The steel metallurgy, hardening and tempering couldn't be bettered even now. I would hate to lose them. You do have top class sfuff, not available here unless you pay silly prices, then they won't be UK made, we don't make anything any longer..
Brian.

[Bikenstein]

Bikenstein, thanks for the blow out step advice although I don't have a bottom tap that size

Don't know if you want to do it, but I have made bottoming taps from grinding plug or starter taps, after runnin them in as far as they would initially go.

[slawsonb]

Bikenstein did you use a bench grinder to do this? Thanks for the idea...
...bert

[BRT-GTR]

Bert
Use plenty of water, short grinds, dip often,  take your time, try to avoid blueing or you'll destroy the tap temper, keep tap as cool as possible.  Brian

[reed]

Bert,
If for some reason there is a problem with the threads on the crankcase have a look at Time serts.
They use Time serts on Porsche engines studs all the time,  i do have all the kits and they work very well.
Thanks.
Steve. 

[slawsonb]

and again...thanks for the pointers guys...Team Bridgestone is what this site should be named!
Said with respect to Richard and the reason the site exists.
...bert

[Bikenstein]

Bikenstein did you use a bench grinder to do this? Thanks for the idea...
...bert

Yes and use water to keep it cool or it will lose it's hardness.

[Bikenstein]

Bikenstein did you use a bench grinder to do this? Thanks for the idea...
...bert

Yes and use water to keep it cool or it will lose it's hardness.
[/quote]

Never mind, I see Brian the Brit already answered the question. Just take a little off at a time between water dips and make sure you grind straight in so as not to damage or dull the threads. Leave the first tapered thread for starting straight (the stud will still bottom out because it has a taper on the end also) and start it carefully. This is a precision job but works well. Also if you don't have another tap, be sure to chase and clean the threads as far as the tap will allow before you modify it.

[slawsonb]

Hey, I really appreciate all you guys jumping in to help the old desert rat. Bought a Motion Pro stud driver today per BS Mechanic's suggestion. This will be the most expensive cylinder stud in history!...love it...
...bert

[Bikenstein]

Hey Desert Rat, don't know if you're interested but there is a GTR parts lookin bike in Phoenix for $100 it's listed in the classifieds

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360701764956&ssPageName=ADME:B:SS:US:3160