After owning several BMW and Audi's with Motronic, some of them new and one of them had some 175.000 miles on the meter, I never ever had a problem with the Motronic system. I don think that is an issue to consider.

915 or G50? I test drove several Carrera 3.2, mostly G50's, before buying my car earlier this year and I can honestly say that none of them felt better than my 915 gearbox. I did drive some really horrible 915's as well where it was very hard to find gears and even harder to shift from third to second gear without making horrible sounds. Anyhow I think that a good 915 is as good as a G50 but a bit slower when trying to shift fast.

My advice is that a well maintained SC is a much better alternative than a neglected Carrera 3.2 that you have pushed your budget over the limit to buy.

Best regards
Anders

 

yes, 136K is awfully low mileage for these engines to go about with a rebuild. if you are going to buy a car with a rebuilt engine, the rebuilding mechanic should have a very *very* good reputation. i'd verify the state of the engine and offer something much lower, ie in your budget, if the car is clean otherwise.
good luck!

 

DM.......I have a black/black 88 carrera for sale, let me know if interested

 

I cant answer the question directly cause I dont own an SC....but I wanted to concur with Jeremy on his point about the O2 sensor. I just replaced it on my 86 and notice quite an increase in off-the-line excelleration...it just pulls harder. The old O2 sensor was covered in foul/white crap... a new one is a good upgrade.

 

* At 146 K and with a rebuild to its history...I think that price is overly optimistic on the part of the seller. As I buyer I would offer $14K and possibly pay $15K if all checked out properly.

See...these days you can get a G50 with under 100K for not too much more than $17K.

Check out the ongoing thread up on Pelican Parts board right now to see what others are paying.

 

ked,

I could be wrong, but I don't think any SCs had thermal reactors.

BTW, I've had my '81 SC since '94. I bought it with 39,000 miles, and it now has 68,000. I have not experienced a single mechanical problem with the engine. In fact, my total expense for unscheduled repairs to the entire car in 9 years and almost 30,000 miles is less $600. It's a truly great car.

 

Speed,
According to Leffingwell's "Porsche 911 Buyer's Guide", the '78 & '79 CA cars had EGR that includes thermal reactors. Plus, when my friend's '79 (CA version) engine was rebuilt, it was noted there was heat related damage which accelerated the need for the overhaul (which included eliminating the EGR components).

For '80, 911's in the US became "50 state models" with the introduction of O2 sensors. Perhaps many CA cars have been subsequently modified.

Btw, some 3.2s exhibited early valve guide wear (due to overly effective seals, it is said, cutting down on lubrication of said guides) that might be a good reason an engine was rebuilt at 70-130K miles. When considering a used car, always try to trace its history to birth via previous owners & service records.

I have had no non-routine issues w/ my '87 as well (knock wood!). IMO, a good 911 is a good sports/GT car, regardless of MY, though "known problems" must be sorted. Generalizing across all years & examples by refering to small samples ("service dept. filled w/ 911s" or "complaints noted on the web") is an incomplete pov. Cheers!

 

todd you are correct in that none of the 3.0L sc's came with thermal reactors. my 78 sc is one of the 1st 50 imported to the US and its got a cat. well not currently due to the fact that i just had my smog check and the test pipe is back on. it was the 2.7's that had the reactors, 75, 76, & 77.

additionally the 78 and 79's had no oxgyn sensor, but had the belt driven air pump.

 

I only know what I have seen (a 1 owner CA '79MY) & what I read (Leffingwell, Anderson & Paternie). All confirm that the CA SCs of '78 & '79 were equipped w/ Air Pump, EGR AND the 50 State Cat. Exhaust Gas Recirculation is a subsystem that performs the function known as "thermal reaction". Perhaps it looks a little different than the 2.7 version. Perhaps your car is not an unmolested CA-specific example. Who knows?

 

ked,

EGR is not the same thing as the thermal reactors. They both are emission control devices, but the thermal reactors used on the 2.7 liter cars were not used on any of the SCs. It was the 2.7's thermal reactors that are "credited" for their relative lack of durability/longevity. k911SC stated exactly what my recollection is.

 

Comparisons between the SC and Carrera are tough. And if I could figure it out, then I would sell one of the two 911's I have right now since I only need one. But I don't think I will be arriving at a conclusion any time soon. Though I do have some preferences. Some of them will seem outright dumb, but when one cannot come up with a conclusion, one starts to look at the idiotic things. For one, I have never liked the fifth gear ratio in the 915 Carrera. It is too high. The SC's 5th is much better. I like the aesthetics of the heater fan arrangement in the motor of the Carrera better. I also like the smoother running of the Motronic. But I love the adjust-ability, reliability, and better throtle response of CIS. I also love the simplicity of CIS and still marvel at how something so simple can work so well. And while I find G50 easier to drive, I have no problems with the 915 when it is in good working order.

Performance-wise, this is very tough. Even though I have read road test results, the SC's I have driven do feel stronger down low, while the Carreras feel stronger at the top. I cannot use my SC as a gauge since it is gutted and is pretty light. It is much faster than either my 88 or an 84 targa my sister owns. Though my sister's targa is misteriously faster than my Carrera coupe. All in all, the differences are tiny since I run very often at the track among stock 911S's, 964's, 993's, and 996's and find that in the end, they all lap pretty equally. I have also noted is that not all SC's and Carreras are the same. Some were faster from day one. Remember these things were hand-built at that time. When I bought my SC ten years ago, cosmetically it was one of the worst I saw. But it was by far the fastest stock SC or Carrera I had driven. And this was a car with no books and records and a lousy maintenance record. I also suspect the SC's original hp numbers. The SC was produced in the era when Porsche used to consistently downplay hp figures. I have seen this in my own SC which regardless of having over 210,000 miles without a rebuild once put out a rear wheel hp number close to what the flywheel should be. Still a mystery to me, though not to my friends who say "I told you so." Oh well.

But in the end, I could never just easily pick one out over the other. I usually pick out the one that is closer to me in the morning. To me, any one of them will do. Though if I could have a Carrera Clubsport, the choice would be a lot easier. Then again, a really nice unmolested SC with a 930/10 motor having the 9.8:1 pistons and large intake with no sunroof in the form of an 81-83 euro, would be great too. Such a car, I know would be faster than a Carrera. What has always attracted me the SC/Carrera series is my rule of thumb for buying a 911. First, find the earliest 911 possible. That's right, forget the usual one-size-fits-all rule that say buy the newest you can afford. Because the older a 911 is, the more fun it is to drive. Not to mention ease of maintenance. Second, find the most durable one possible. When one mixes those two mindsets, they will arrive at the SC/Carrera since any earlier will sacrifice durability, and any newer will sacrifice driver involvement. But if one sends me any flat-six car without water in the motor, I would never kick it out of my garage.

 

Todd, thanks for clarifying this point. Let's not overlook that a subsystem that introduces or recirculates heat into an engine that has reached operating temp. is probably a bad thing. For myself I would be wary of a CA spec SC from '78 & '79 because of the EGR. Many early pollution control systems were rushed into production, brute force approaches that had to manage the over-rich cold start / cold running period. One other point, aren't there other reasons that the 2.7 engines were less than ideal in design? Head studs (mismatched thermal expansion) and mag alloy block have been pointed out.

 

ked,
The 2.7's problems are often attributed to its having outgrown the magnesium block. The pre-2.7 cars with the mag block have fewer problems, but they also don't have thermal reactors. Interestingly, the RoW 2.7s seem to be more durable than the thermal reactor-equipped US cars, but even the euro 2.7s are far less durable than other 911 engines. I've always thought it interesting that the 2.7 engine problem issue never seems to come up in any discussion of that most-revered of 911s, the 2.7 Carrera RS.

Ed,
Well said. FWIW, a friend of mine ran a side-by-side rolling acceleration comparison between his '86 Carrera (915 box) and a G50 Carrera. Both cars were completely stock. The 915-box car was considerably quicker than the G50. He has weighed the two gearboxes and says the 915 is significantly lighter, though I don't recall the number. Looking at the old road tests, the 915-box Carreras do seem to be quicker than the G50 cars in general. Perhaps weight (from the G50 and other added equipment that the later cars acquired) has something to do with this.

Ed, would you kick a 959 (water-cooled heads) out of your garage? That's one flat-six car I'd keep! And I take it that you'd keep a Corvair...

 

Damn, Todd, you got me there. Yeah, that one I would put in. After all, the wipers on that car have a 180 degree sweep and park on the driver's side, which is a requirement of mine.