Name That Stud

1972_911T · 01:18 PM

I spent this morning removing broke studs from my newly accuired 3.0 Case. This is a very starge setup 9 of the 12 lower studs were broken however none appeared to be diliver. on one side 4 were broken this was fitted with what look like STK OEM studs on the otherside 5 were broken 2 had only a few mm out of the case these appeared to be some sort of aftermarket stud can anyone identify them?

Isnt it uncommon for steel studs to break?

Steve

Eagledriver · 03-03-2007, 07:11 PM

I see you used my favorite method of stud removal. Weld on a nut. They look like Dilivar to me. They are very shiny.

-Andy

1972_911T · 03-03-2007, 10:30 PM

Ive just compared the shiny studs to a diliver stud I have, the shaft on the diliver stud is thinner it measures 7.8mm on the shaft, the studs in my photo measure 8.9mm so unless theres different types of diliver other than the fully threaded 993 ones its not that.

Steve

Eagledriver · 03-04-2007, 11:21 AM

I think that different years had different sizes. An easy check is to see if they are attracted by a magnet. Dilivar behaves like it's not steel-magnets aren't attracted by it. Compare to a steel stud.

-Andy

David · David's Garage

I'd say the 3 on the right are Dilavar, hard to tell on the others.

mb911 · mb911's Garage

4 on right are dilivar(a stainless base it gets the gold coloration when you take a tig torch to it) and the the others are steel..

1972_911T · 03-08-2007, 10:04 AM

I tested the shiny studs today with a magnet and they had no attraction so they are probably diliver, the other studs are steel and identical to the ones in the top row and have the same marking on the end of the stud, if these are STK steel studs isnt it unusual for them to break?

Steev

Jeff Alton · 03-08-2007, 08:36 PM

Yep, pretty unusual for steel studs to break, infact very unusual. I am sure henry or another more experienced builder can say if they have seen a broken steel stud. I my limited experience I can say I have not seen one.

The question is, what steel studs are those?

What is the rebuild history of the engine? At some point were the only studs did all of the dilivar ones break first leaving the steel as the only ones intact, until they failed?

If there was a mixture of studs on the bottom row, as it now appears, one may suspect a very budget oriented rebuild of some sort took place in the past.

I am interested to know more of the history of the motor.

Cheers

1972_911T · 03-08-2007, 09:48 PM

Hi Jeff

I have no histry of the motor other than the PO bought it for parts with broken studs. The studs werent mixed as such, one side had all dilvers on the bottom while the other side had all STK steel ones on the bottom.

Steve

Jeff Alton · 03-08-2007, 10:04 PM

Wow, strange how some of the steel studs (which were on one side) broke. How far have you torn the motor down? What, if any, is some of the other damage/wear?

Cheers

1972_911T · 03-08-2007, 10:08 PM

Yes the engine is now completly stripped, crank, rods and case internals all seem good.

Steve

Jeff Alton · 03-08-2007, 10:35 PM

Very strange, at least you now have the chance to put a new set of studs in!!

I gotta go to bed!

Cheers