Should I buy a 911SC?

[Mark Salvetti]

I think all things being equal, I would go for a 3.2 with the Motronic. But things are rarely equal, and if I found another SC that was the right color and was in better condition than a comparable 3.2, I wouldn’t hesitate to buy another.

Lately it seems that even the 3.2’s are starting to see broken head studs. To the point that I think I would also consider an SC with a recent rebuild and new studs as a better choice than a 3.2 with original head studs.

Mark

[87maniac]

I've owned a '83 SC and '87 3.2 G50.

I went throught the learning curve of how to adjust/tune CIS, and it was very reliable.
The big difference is the torque/power of the 3.2.
3.2 Carrera is more fun to drive.

Both are ultra reliable.

[boyt911sc]

Originally Posted by ksluna

Might be a stupid question but I thought you had to constantly adjust the mixture with CIS? So when people like the above poster who "threw in the towel" with CIS, is it not necessarily for adjustment but the wearing down of parts that need to be replaced?

Ksluna,

The people who starts tinkering the fuel mixture on the fly are the ones giving up on CIS. The lack of knowledge and understanding is the major problem for CIS owners. You don’t tinker the fuel mixture on the fly like you do with carburetors. That is the last thing you adjust. Once it is set, do no touch it. That’s the reason they put a plug to the access hole. So people who have no experience setting up the fuel mixture would only make the problem worse.

Look for ROW SC (‘78~’83) all have the larger intake runners and no OXS/ECU. However, the US/CAN spec late SC’s have better fuel economy and reliable like the rest of the SC family. If you are not handy, find a mechanic who understands and works with CIS cars. Or start to learn how to work with your CIS car. Do not make a comparison between CIS and Motronic. They are two totally different systems and introduced in different era.

Tony

[pmax]

Originally Posted by ksluna

I suppose I had a bad experience with a carbed motorcycle, and I know it's not the same thing as CIS, but the worst feeling in the world was trying to start your bike on a beautiful day and it won't start! I would hate for it to happen in my 911.

Compared to caveman carbs, the cap will vehemently disagree, CIS is an elegant, and basically linear, system. Get the knobs set right, and it will start.

It is ancient tech compared to modern day EFI, but amazingly Porsche still supports and sells replacement parts !

[SkiVT]

I have an 83 euro SC as Tony mentions. In Vt, you see temps ranging from the high 30’s to mid 90’s across the driving season. I installed an afr gauge mostly to see what is happening, not to constantly adjust the mixture. The main difference across the seasons is the transition time from cold running to warm running. If the engine isnt running properly, the cis components are mostly rebuildable or available new (airbox as one example). The testing for all the CIS components is very easy with assistance from this forum. Buy an SC and dont look back!!!!

[SCadaddle]

Originally Posted by ksluna

Thanks for all the info guys...

I think I will consider SCs or at least not be so scared of CIS.

Craig_D -- if you do a search on this forum or rennlist I would say A LOT of people have compared these two, and generally one of the main things they will say is that the Motronic > CIS.

Like I said, I don't care about the differences in performance or the 915 vs G50 debate. I just want a fun car that I can do the basics on and will start up every time (I do plan on driving it often, but not as a DD). What I'm expecting out of this car is to learn how to do most of the work myself, but of course the more complicated things I wouldn't have time or the skills for so I would want to take it to a shop. I just don't want to buy a CIS car and always be "tinkering"

I suppose I had a bad experience with a carbed motorcycle, and I know it's not the same thing as CIS, but the worst feeling in the world was trying to start your bike on a beautiful day and it won't start! I would hate for it to happen in my 911.

On another note, this car is interesting - 74 911 coupe

If you think the "worst" feeling in the world is a bike that won't start on a beautiful day, you're probably not ready for an SC, 3.2 Carrera or a 964 with broken head studs. It's not a matter of IF they will break, it's a matter of WHEN they will break.

[roblav]

SC's are heavy and CIS is boring. But I had multiple 1966 to 1972 cars as daily drivers. I admit to my biases.

[ramonesfreak]

Originally Posted by roblav

SC's are heavy and CIS is boring. But I had multiple 1966 to 1972 cars as daily drivers. I admit to my biases.

I sure would love one of those but I certainly don’t have 100k+ to spend on a nice original rust free one

And since I never owned an old long hood, my SC feels very light. It’s all relative

Of course I look at these issues as someone who only paid 12k for my car when they were cheap and not in the 30k-50k range that they are today.

Compared to most cars, my SC feels like a go kart and very nimble and never boring oh and the body is galvanized

As for broken head studs. Big deal. Plan for it. Once you fix them, your unlikely to have to address the issue again. If you start with a solid rust free car with a motor in good health there really are few major issues to deal with with the SC

Any vintage car is going to have some expensive inconvenient issues that will need to be addressed. The pain of this is reduced if your long term plan is to keep the car

[Coastr]

Should you buy an SC? Yes.

Is the 3.2 motronic a better engine? Yes.

Are 3.2 cars more expensive because of the better engine? Yes.

Is the CIS finicky and requiring constant fiddling? No.

Can you fit modern Efi to an SC? Yes. For less than the price difference to a 3.2? It’s close...

[HarryD]

I have a 1973.5 911T. It is the worlds first production CIS Car. I have had it since 2002. CIS was adjusted no more than 3 times during my (current 50,000 mile) ownership.

1-When I first got it to fix a surging issue;
2-When I replaced the worn valve guides;
3-When I needed to repair a damaged cylinder.

There is an old saying about CIS:

1) The guys with working CIS systems are probably out driving their cars so they won't reply.
2) The guys that tinker with their CIS systems and have them royally screwed up will keep you running in circles with suggestions.
3) The guys that have spent a fortune on Webers or aftermarket EFI will tell you they're great to justify their expenditure to themselves.

I belong to group 1.

Downside of CIS is that it will not tolerate a hot cam and you do not get the cool induction sound of individual throttle bodies/carbs.

Upside, it that it just starts and runs.

[HarryD]

For your consideration:

K-Jetronic debuted in the 1973.5 Porsche 911T in January 1973, and was later installed into a number of Porsche, Volkswagen, Audi, BMW, Mercedes-Benz, Rolls-Royce, Bentley, Lotus, Ferrari, Nissan, Peugeot, Renault, Volvo, Saab, TVR and Ford automobiles. The final car to use K-Jetronic was the 1994 Porsche 911 Turbo 3.6.

[RSBob]

Originally Posted by HarryD

I have a 1973.5 911T. It is the worlds first production CIS Car. I have had it since 2002. CIS was adjusted no more than 3 times during my (current 50,000 mile) ownership.

1-When I first got it to fix a surging issue;
2-When I replaced the worn valve guides;
3-When I needed to repair a damaged cylinder.

There is an old saying about CIS:

1) The guys with working CIS systems are probably out driving their cars so they won't reply.
2) The guys that tinker with their CIS systems and have them royally screwed up will keep you running in circles with suggestions.
3) The guys that have spent a fortune on Webers or aftermarket EFI will tell you they're great to justify their expenditure to themselves.

I belong to group 1.

Downside of CIS is that it will not tolerate a hot cam and you do not get the cool induction sound of individual throttle bodies/carbs.

Upside, it that it just starts and runs.

I belong to group 3 and spend every waking moment of every day trying to reconcile/justify the $ Spent versus better throttle response, mo power and that insane intake sound. After a year the $ side is losing, but tomorrow is another day...

[tirwin]

I’ve owned my SC for 8 years. When I bought it I knew less than nothing. It is a totally different car since I bought it. Get in. Turn the key. Fires right up every time. So, yes, once CIS is working properly, it is a great car.

If I were in the market today, the only thing that would keep me from buying an SC is if I wanted to hot rod the motor, the SC is not a great choice. 3.2 or 3.6 is a much better starting point in that regard.

[Rawknees'Turbo]

Originally Posted by HarryD

. . .

There is an old saying about CIS:

1) The guys with working CIS systems are probably out driving their cars so they won't reply.
2) The guys that tinker with their CIS systems and have them royally screwed up will keep you running in circles with suggestions.
3) The guys that have spent a fortune on Webers or aftermarket EFI will tell you they're great to justify their expenditure to themselves.

. . .

It might be an old saying, but it is definitely no less full of hogwash than when it was new.

[DonNewton]

I've owned my '83 SC since '83, yes, original owner. I have over 135K on the clock and except for head studs popping when I came home from Desert Storm, my SC has run like a German tank. I can tell you that if the system is set correctly, you'll have no problems. The car has been from California to Rhode Island, California to Virginia and back to California. Runs perfectly.

[nene]

"And there you go, well said!"

Originally Posted by DonNewton

I've owned my '83 SC since '83, yes, original owner. I have over 135K on the clock and except for head studs popping when I came home from Desert Storm, my SC has run like a German tank. I can tell you that if the system is set correctly, you'll have no problems. The car has been from California to Rhode Island, California to Virginia and back to California. Runs perfectly.

[Superman]

I have owned and driven several German cars with CIS. Three of them were 911SCs. Others were VWs and Audis. Starting in the early 1980s and continuing to the present day. None of those cars had fuel system problems. Every single one of them started quickly and easily, and immediately ran as if they were already warmed up.

That said, I understand CIS systems are somewhat complex and can fail. If my current 1978SC needed expensive repair to the CIS system, I would consider switching to EFI or carbs.

Yes. Get thyself a G-bodied Porsche. Funnest car I have ever driven.

[uwanna]

Originally Posted by tirwin

I’ve owned my SC for 8 years. When I bought it I knew less than nothing. It is a totally different car since I bought it. Get in. Turn the key. Fires right up every time. So, yes, once CIS is working properly, it is a great car.

If I were in the market today, the only thing that would keep me from buying an SC is if I wanted to hot rod the motor, the SC is not a great choice. 3.2 or 3.6 is a much better starting point in that regard.

Hey Tim,
You're not quite telling the whole story. Don't sell yourself short. When you pulled your motor you pretty much restored your whole CIS system with WUR, injectors, etc etc. You did a magnificent job and your CIS system runs like new and will probably run like a top for years to come. You did it right, like everything you do with that beautiful car!
Cheers,
Grant

[G450X]

I’ve had a high mile (160k+) ‘82 for about 10 years with only one CIS problem - a backfire blew the pop off valve off inside my air box and I had to epoxy it back in.

This thing starts immediately and runs well, only mods are SSI’s and an M&K 2/1. If I had to put money on which one of my several oddball vehicles will start, it would be my SC or ‘79 Scout...

[da Vinci Dan]

Ksluna, you and I are similar in our mechanical background, skill set, and use of our cars. The most important factor in the enjoyment of my 911 ownership is access to a reliable Porsche specialist. After 12 years of 911 ownership, I now have two whom I could text anytime. My most recent purchase has been a completely mechanically refreshed ‘88, done by the prior owner. For me, this is the best way to go.

I have only owned ‘84 or new models. Even with these “more reliable” models, I have had multiple issues with engine management - all very minor. However, a no-start or stumbling situation can be very challenging and frustrating for a novice to handle.

You are buying your car for fun. Get one that has been well maintained, even if it has higher miles. As stated prior, headstuds and trans issues are much more expensive and problematic. Rust, suspension, exhaust, interior bits and pieces... the list goes on. IF it runs well, has been cared for, and is in your price range, go for it.

Make friends with your specialists.