Noel

I was just talking with my mechanic about my desire to purchase a 911SC as a third car that I could use for weekend, autocross and track event use. He indicated to me that those cars have a really bad problem with the head studs breaking and that it is such an expensive repair that I sould consider a late 80s Carrera instead. I liked the idea of an SC because it would be easier for me to work on myself and I have heard that the engines were "Bullet Proof." Are these engines really not bullet proof? I can't find reference to this type of problem in any information I have. (Although I know it is a problem with the 2.7L engines.) Someone enlighten me.

emcon5

I don't think it has become a big enough problem to avoid buying a SC altogether, but it is an expensive enough problem to have them checked in a PPI. Look at the SC FAQ, or go search the Pelican BBS archives.

On a related note, my Parts and Technical Ref Catalog lists the same part numbers for head studs from 74-89. Does this mean as the Carreras age, they will start seeing stud breakage as well?

Tom

JJM

Noel,

The SC does not have an inherent problem with broken head studs. As with any engine the possibilty exists but the 3.0 is not prone to this problem. The 2.7s have the head stud reputation because of the material of case thus allowing the head studs to pull loose. Anyone else out there with additional tech info on this? Anyway Porsche became aware of the head stud problem with the 2.7s and corrected this (among other things) when engineering the 3.0 SC motor. The 3.0 liter SC engine is as solid as the rock of Gilbraltar, period. Buy 911 and you will find yourself sitting in the garage admiring it at night instead of watching Seinfeld re-runs. Always have a PPI for any serious candidate you find.

Noel

Seinfeld re-runs? It's like you know my daily routine.
Thanks for your sharing your wisdom. I was convinced I wanted an SC, but began doubting myself after that conversation.

Many Thanks,

Noel

john brasfield

from my experience, it seems the SC's break studs when they sit for a while. I knew a guy who got 300k out of his and let it sit for a year. Brought it up again and upon getting tuned up, they found several bad studs. My engine sat for 4 years had about 50k on it and when I rechecked the torque before putting it it, 2 were broken. Corrosion is the problem and I bet Southern humidity makes the problem worse. I put racewares in and hope they last a good long time.
John

john walkers workshop

jjm, do a search and you will find lots of broken head stud problems on SCs. the 2.7s pulled them, the 3.0s broke them. search pelican too. it's not like every SC has the problem, but it's common enough that a PPI on an SC should include draining the engine oil and removing the lower valve covers to check them.

TYPE911

John~

How will a 3.0 engine perform if the headstuds are broken? Is there a noticeable
difference?

Thanks

Chris
82 911sc
just turned 40,000

emcon5

Anyone?

Kevin

Emcon;

The dilivar studs do break, don't stop at the carrera, the problem exists with the 3.6. It is wise to replace them with ARP or Raceware studs.

Chris Bennet

Here in the northeast 3.2L headstuds are not immune. They corrode through. (I'm in the process of fixing one now.)
-Chris

john walkers workshop

chris in colorado, some engines run fine and don't make any exhaust noise at all. (usually the ones with just one stud broken). usually the clue that there are broken studs is the "hole in the muffler" sound on acceleration. there is usually an oil leak between the head and cylinder in addition. heads loose enough to make noise cause a noticeable power loss, and damage to the head, cylinder, and possibly the case if let go long enough.

jlkline

I bought my 3.0 engine used from Canada from an 83cab. The mileage was claimed to be 48K, and this seemed accurate, but I had no documentation to confirm.

About a year and a half after the transplant replacing the original 2.7 leaky ***, stud pulling boat anchor with this 3.0, I broke a lower stud. It made the motor sound like a popcorn manchine. I suspect it was the corrosion problem charateristic of the dilavars. I replaced them all with the 993 factory studs(nearly completely threaded from both ends, and smooth in the center) didn't do anything else, and kept goin' for 7 years until it was rebuilt to a 3.2. It was nice not having the expense or worry of new studs in the rebuild.

Thom Fitzpatrick

My 3.6L broke 2 studs, and I was aghast, until I heard others had had similar problems. The data points that I have would indicate that on the 3.6's it's a potetial problem after a rebuild. FWIW, I went to RaceWare head studs.

Jdub

Noel:

The worst-case scenario for both the SC and the Carrera are broken studs and worn valve guides, respectively. I know we aren't talking Carreras, but you should include them in your search if po$$ible.

Your budget may decide for you. At 13-20K you have your SCs, and at 16-25+K you have your Carreras. I own an SC, and love it, but the Carrera has the 3.2 and many amenities and there is no substitute for HP!

Either way, the PPI is critical. Make sure they go through every electrical switch as well: brights to defroster (esp w/ a Targa). This is something that is not regularly done on a PPI so be prepared maybe to spend a bit more or give them the libations of their choice.

Good Luck,
Jw