POLL: Broken Head stud

rlane · 02-21-2005, 06:45 PM

OK, did my 78 SC's valve adjustment today and as I was adjusting #2's exhaust SOMETHING dropped out on my arm!. Yes, it was a broken head stud out of the front upper #2. Quickly checked the rest and all seem OK (though I was scared to put much torque on the allen wrench. So I searched all the posts and sure I need to do a top end rebuild but time and money are in short supply. This is my weekend, occasional drive to work car, the 73 does all the track time now, I would like everybodys opinion on if OK to drive til next fall/winetr when I will drop the engine and try the rebuild myself (plus a clutch and god knows what else).
So....
A) quit whining and drop the engine now
B) take it easy on the road and stock up fro next winters big project
C)drive it as usual

swackdog · 02-21-2005, 07:43 PM

Richard,

I've been down this road. Bought my 911 in May, 04 and later discovered that I had 3 broken exhaust head studs so I did a partially top end rebuild (all new head studs & rings). From my reading and talking with several shops, you should drop the engine and replace the head studs (recommend that you replace all of them) as soon as possilbe. If you continue to run the engine, you could damage the mating surface between the cylinder and the head as the cylinder loosens up.

PS Wayne's book was a big help.

swackdog · 02-21-2005, 07:45 PM

Richard,

Just noticed you are in central Kentucky -- where? I live in Benton.

Go Wildcats!!

rlane · 02-22-2005, 05:41 AM

I am in Mt Sterling, 30 miles east of Lexington , on I64
I am pretty bummed to find this issue..see my post on "One thing leads toanother" !

sammyg2 · 02-22-2005, 06:00 AM

If it was on the end (#1 or 3) I would say do it now. Because it is in the middle it is supported better by the cam housing and has less chance of leaking.

My SC had a broken head stud on #5 when I bought it (I knew about it and adjusted the price accordingly).

I drove it for 2 years that way, six months of that was under boost.
Eventually I tore it apart, no damage at all.

Yes I got lucky, admittedly others might not be as lucky.
There is a chance that driving it that way will cause damage but I would bet it won't. Your call, roll the dice.

Rick Lee · Rick Lee's Garage

Just finished the engine break-in process last night, started by discovering two broken studs on Jan. 4th. Now I have a super clean, leak-free, upgraded engine, all new 993 epoxied studs. I feel a lot better this way. Head studs were fine when I first inspected the car in Nov., so the two that broke did so within 2 mos. of my having it, which I caught before they did any more damage. Get on this now.

rlane · 02-22-2005, 01:55 PM

Thanks Sam and Rick....both with great advice but just 180 degrees opposed..hmm like our motors..
If this was November I weould drop the motor and do it but its getting to be driving time!. More poll input?

sammyg2 · 02-22-2005, 03:42 PM

I said you would probably be OK for a while, but no guaranties.
There is risk involved. If you don't want to take the risk then Rick is right on, rebuild it now.
Howz that fer backpeddaling?

Evans, Marv · 02-22-2005, 03:50 PM

Richard:
I agree with Sammy. Not that I'd drive it for a long period of time that way. But you might try a compression check on that cylinder. If it's got lower compression, that would indicate a leak. If not, you could drive it for a little while.

Rick Lee · Rick Lee's Garage

I'm a maint. fanatic and this SC is to be my dedicated track car. So I don't drive an inch when I know there's the slightest problem to fix.

Zeke · 02-22-2005, 04:13 PM

I know nothing. I just wanted to say hi, Richard.

BTW, Richard is the one who did the inspection on my car that I bought sight unseen. A great Pelican!

PS, I know you could drive the car on the easy side for sometime to come w/o necessarily ruining anything. But......., can you drive on the easy side?

I've always wanted to as this on a stud thread: Why isn't there a "super stud" for 911s like the ones for VWs that have a bigger end at the case? I'm gonna attempt to answer my own question. It must be because the problem is either with the case itself, or the shank of the stud. On VWs, it was the case, and the bigger threads tapped into the case did the deal. Of course, that was at 7.something:1 compression.

As always, thanks Richard. If you were nearby, I'd come over and help you get those studs replaced.

rlane · 02-22-2005, 07:05 PM

Hey Milt..how is the S coming along?
I am also finishing repairing a few rust spots on my 73 track car and putting elephant oil lines and a front cooler on it, first DE of the season is April 16th...not too long away !
My garage buddy bought that Beck 904 body off eBay and ...once he finishs his 68 track car project, will commence that challenge.
I think I am gonna wait til next fall to do the engine drop and teardown, spring and summer get awfully busy...and its too much fun to drive!

yelcab1 · 02-22-2005, 07:23 PM

I would fix it now, but that is if I had the money. Otherwise, i park it until it is fixed.

Bobboloo · Bobboloo's Garage

I vote drive it. What's the worst case senerio. You have to buy a head come winter? That's not so bad. You no what is bad though, two cars on jackstands and no Porsches to drive. Now that's just torture. I've been there.

Take your time and make plans for it come winter.

rlane · 02-23-2005, 06:54 AM

Bobby, It is not too bad right now because our weather has been nasty, cold and rainy...but spring is coming soon so I got to get these guys buttoned back up, I am just afraid that when I get the oil cooler on the track car, fenders back on and start going thru it for the first DE I will go overboard on it the same as I did the SC. I'll check the brakes and first thing you know I will rebuild all 4 calipers, install new lines and cooling ducts. Then I will adjust the valves (cross fingers I find no broken studs on it!! The PO supposedly put in Raceware studs when he built the RS spec motor). Probably look at the CV's and say..hmm probably R&R those...well you know how it goes!