1974 Carrera 2.7 - Head Studs?

I am very close to purchasing a rare, 1974 Carrera 2.7. Unlike the Carrera 2.7's that were delivered to the United States, Australian delivered Carrera 2.7's came with the MFI 911/83 engine straight from the Carrera RS from the previous year, along with the same brakes, transmission and suspension geometry.

The situation I'm in is eerily similar to the topic authored by Shakenbake; '74 911 137k...original head studs possible?' (http://www.pelicanparts.com/ultimate/Forum3/HTML/000956.html)

The car I'm looking at traveled 111,000 miles before it was rebuilt with high compression (9.8:1) pistons. The owner responsible for the rebuild was (supposedly) an enthusiast and was appropriately involved in club activities.

Pardon the ignorance, but do high compression pistons increase thermodynamic rates inside the case? Is cylinder expansion exaggerated with high compression pistons compared with the standard compression pistons? If so, would it have been academic & necessary for high tensile studs and serts to have been used, apart from being an opportunistic and advantageous modification?

While the current owner of the car is not sure if the studs were attended to when the engine was rebuilt, by my reckoning, I'm sure if someone was inclined to use high compression pistons, they would have been well aware of head studs modifications, and would've been inclined to opt for that modification as well.

The car has traveled 45,000 miles post the rebuild. The studs have never pulled; the current (reputed) mechanic who has worked on the car for the last seven years says that he would be very surprised, even shocked if the studs decided to withdraw now or in the next 50,000 miles. I asked him whether it was possible to ascertain if a certain type of stud and sert combination was used. He said it was difficult, but given the history of the engine, unwarranted. Should I take heed of his advice, or should I continue to be wary? Is this just the calm before the storm? Are MFI 2.7's less prone to pulled studs as I've been told, or should I just listen to the guy who knows the car better than anyone and just relax?

The only reason I'm considering this 74' Carrera is that my otherwise pristine 76' CIS 2.7 has suffered from head stud withdrawal TWICE in the 18 months I have owned it, and the 6,000 miles I have driven it! There is cause for my paranoia, but I don't think I could a) afford or b) retain my sanity if it was to happen to me once more.

Any suggestions/wisdom/advice would be most appreciated.


-Matt Holcomb

Most of us MFI enthusiasts wish we had your worries about an RS 2.7 purchase! But, at the same time, have no experience with the engine to address your concerns. In general, the MFI has a tendency to run rich, rather than lean like the CIS systems, and not having any smog controls, in spite of the slight compression increase from 8.5 to 9.8, I really doubt if you have anything to worry about! At that age, I think I might be more concerned about the care and feeding of the 915 transaxle, because if it has been neglected ... it may be time for a rebuild, soon. Is the gear oil in the transaxle at the correct level at the filler plug hole, and is it fresh and clean? Congradulations on your acquisition of what has to be the most revered 911 in Porsche history!

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Warren Hall
1973 911S Targa

Warren,

I'm really not sure if the gear oil on the transaxle is at the correct level at the filler plug hole, or if it's fresh and clean.
I assume that because the car has been maintained fastidiously its entire life, that the levels and the cleanliness of the oil should both be fine. However, I will be giving the car the once over before I write out the check, and that's one thing I will have looked at. Thanks for the heads up.

Let me just clarify something. The 1974 Carrera 2.7 is a 1973 Carrera RS repackaged as an impact bumper 2.7. Yes, essentially, it's a 73' Carrera RS, but only if you take away the rear seats, electric windows; replace the panels with the lightweight panels, and add the duck fin and narrow bumpers. Until you do that, what you have is a heavier, more practical impact bumper 911, but with the heart and soul of the 73' Carrera RS. Perhaps, the best of both worlds.

But it's still no 1973 Carrera RS!


-Matt Holcomb

Hi Matt

I am a fellow Melbournian and early Porsche owner.

I can’t offer any advice on your potential purchase but I can provide a VERY strong recommendation of a mechanic who can help you should you require the car checked over.

John Gregory of Spyder Automobiles is, from my investigations, probably one of the most highly regarded early Porsche guys in the market (he has also serviced my car for the last 12 months). I understand he is who all the major service centres turn to for advice when things go “pear shape”, on their clients early cars. He is great for advice and is happy to talk through any issues, which he happily did for the 8+ months it took me to find the right car. Importantly he is one of the few Porsche mechanics who don’t have a “rape and pillage” pricing policy for your future servicing and repair requirements. If you have any doubts about this guy ask him about his Porsche background, which started as running “Hamiltons” service centre.

Best of luck with your potential purchase.

Paul,

Louis Giosis who IS MOTION AUTOMOTIVE has been looking after the car for the last seven years. I've only heard great things about Louis, but I've also heard great things about John Gregory of Spyder Automobiles.

I may give John a call next week and then contrast his advice/opinions/expertise with that of Louis's.

Thanks,

-Matt Holcomb

Matt

I haven’t heard of Lois, which isn’t to say that he isn’t knowledgable and can’t give you the right advice. My previous comments are only based personal experience and lots of research. We all know what these cars cost when they go wrong, and for mine, a second opinion on a purchase could only represent firm investment in peace of mind.

If you are interested John’s number is 9532 0246 and he is based in Cheltenham. I suggest dropping in, seeing him and at least getting him to drive the car and offer an opinion. He is what I think of as a real old style mechanic, who specialises and has a passion for the cars which, after restoring 2 MG’s to race and E type Jag, can attest is hard to find. Having extolled his virtues I should add that I have no interest in his business or its promotion other than being one of many happy customers.

Regards,


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Paul
911T'69

You should definetly have this car checked
over before you buy it, especially if you
have concerns about Head studs pulling.

Have a compression test and leak down test
done. Plus the overall condition of the
car should be checked out by someone objective. Do not bring it to the person that has been doing the work on the car.

Head stud problems is an expensive propostion. If the current seller balks at
having the car checked before you buy it by the mechanic of your chioce there is likely something wrong. Just walk away...

Just my opinion.
Good Luck
Joe A.