Another Head Stud Dilemma

Crowbob · 07-09-2003, 10:27 AM

ABOUT TWO WEEKS AGO I TORQUED THE CAM HOUSINGS, HEADS AND CYLINDERS TO SPECS IN WAYNE'S BOOK, INSTALLED BOTH CAMS, 1 AND 4 INTAKE ROCKERS, AND WAS BEGINNING THE PROCESS OF PROCURING A DIAL GAUGE TO SET THE CAM TIMING. SOMETIME DURING THE 14TH NIGHT AFTER THE TORQUING, THE PORSCHERGEIST VISITED AND LEFT, AS INDISPUTABLE EVIDENCE, A BARREL NUT STILL ATTACHED TO IT'S STUD ON THE FLOOR ABOUT THREE FEET FROM THE ENGINE. THE THICK WASHER WAS ABOUT FOUR FEET FROM THE ENGINE. THE STUD WAS BUSTED ABOUT ONE INCH FROM THE NUT END. SO, HAVING GONE SO FAR IN THIS PROJECT, AND HAVING LEARNED NOT TO LET THESE MYSTERIES BOTHER ME TO DISTRACTION AS THEY SEEM TO DO, I SURMISED THE STUD WAS BAD AND THE EVER SO SLIGHTLY WARMER TEMPERATURE OF MY GARAGE CAUSED THE CASE TO EXPAND AND THE FAULTY STUD TO BREAK OFF. HAS ANYONE HAD THIS EXPERIENCE BEFORE? DO I HAVE TO DISSASSEMBLE EVERYTHING TO REPLACE THE STUD OR CAN I REMOVE THE CHAIN HOUSING, CAM HOUSING, AND HEADS AS A SINGLE UNIT? CAN I REPLACE ONLY THE CULPRIT STUD (OR ALL OF THEM)? AND DO THE CE RINGS NEED TO BE REPLACED, TOO?

Tim Walsh · Tim Walsh's Garage

Was the stud divlar or steel?

john walker's workshop · 07-09-2003, 12:09 PM

the head/cam tower unit can be removed as a unit. the head gasket rings should be replaced, because they have been crushed. some years ago, there was a batch of black painted dilivar studs that would pop after torqueing. had a few do that here. only the lowers are dilivars, except 930s which had all 24, and replacing them all with steel stiuds, like on the top row, would be recommended, rather than just replacing the broken one and hoping that no more break.

Crowbob · 07-11-2003, 01:24 PM

I DON'T KNOW HOW TO TELL THE DIFFERENCE BETWEEN DILIVAR AND STEEL. ALSO, I REALIZE THE CAM TOWERS AND HEADS NEED NOT BE DISSASSEMBLED TO REMOVE, BUT WHAT ABOUT THE CHAIN HOUSING? CAN IT STAY TORQUED TO THE CAM HOUSING WITH THE CAM STILL ATTACHED THUS BEING REMOVED AS ONE BIG UNIT? I'M TRYING TO AVOID REMOVING, CLEANING AND RESEALING THE TRIANGULAR PAPER AND RUBBER O-RING THAT HAS SEALANT (CURIL-T) PER WAYNE'S BOOK.

john walker's workshop · 07-11-2003, 01:38 PM

take off the chain housings. no big deal really. if you don't want to, pull the rockers and cams, because the cam snout won't clear the housing. pull heads, cam towers w/chain housings attached? too mousy. a juggling feat. possible, but mousy. dilivar won't attract a magnet. your cap lock is stuck on.

Groesbeck Hurricane · 07-11-2003, 01:54 PM

Jim,

JW is The Man!! Don't cheap out on replacing the o-ring. It really is not worth it. Go the tried and true path.

Also, turn off the cap lock. It appears as though you are yelling.

Bill Verburg · Bill Verburg's Garage

The black coated one is Dilivar, the other is steel

Crowbob · 07-14-2003, 03:22 AM

Thank you all for your advice. Sorry about the caps lock. Looks like I'll be replacing studs, etc. I'm glad this happened before the engine was reinstalled, so it is just as well. It sure is good to know there are guys out there who are so willing to offer their advice and expertise! Again, thanks to all!

Crowbob · 07-21-2003, 12:10 PM

Gentlemen:

I have removed the offending broken Dilivar stud along with the remaining 5 on the right side of the engine. These will be replaced with steel. I am also going to replace the ce rings/crush gaskets. Now I need to know what the consensus is regarding the copper gaskets/shims between the cylinders and the case. Do those need replacing also? Does it make sense to re-tear down the left side to replace the studs there or am I being over cautious in my rebuild?

Groesbeck Hurricane · 07-21-2003, 02:09 PM

Jim,

I would replace the copper gaskets/shims.

If this were my engine and I had to replace the Dilivar studs on one side because of the break I would do the same thing to the other side. Two reasons: 1) If it breaks on one side, the very same thing could happen on the other. 2) Balance. I'm a little anal here, but if you have the vehicle set up one way on one side, it should be a mirror on the other. This might not be a real issue and could only be a personal choice. The experts here will know!

Wayne 962 · Wayne 962's Garage

Yup, replace all the studs. The steel ones are magnetic, the Dilavar ones shouldn't be magnetic.

-Wayne