80 to 83 SC, What's the diff?
 

I'm learnin' but I'm still a newbe. What are the major differences between the years of the SC's?

Westy.

Lookin' for an SC

The late model SC motor (late '83) had a little bit more ooomf than the others with higher compression(9.8 compared to 8.5:1) and a 3.2 case. Good for about 10Hp I think.

m.

US model SC's are generally grouped into two sets. The 78 & 79 models and the 80 through 83 models. The later models had a higher compression 9.3:1, a three way cat with an oxygen sensor, smaller intake ports and runners, better gas mileage, but probably slightly less power. The later model cars usually had a bit more equipment on them.

Early cars had the cam timing retarded for more power, bigger ports and intake runners, a 2 way cat and an air pump for emissions, lower compression (8.5:1?)and potentially less equipment.

In reality, there's not much difference between them. Just buy a good one.

ROW models were slightly updated in 80 with HP now rated at 188 DIN, then upgraded with Higher comression and revised cam timing to 204HP DIN in 1981.

Jerry Kroeger

Westy,

Welcome aboard!! There are small differences between '80 and '83 models, but there are almost none between '82 and '83. I would not say you have to stay within a certain year, a well sorted out SC of any year will do you well. Make sure you get a PPI and ask questions. Take photos and post here for opinions. Don't let out your source for the vehicle if everything is feeling good.

Very few of the very first ones you ever look at will actually be "the" car you should get. Look around, spend a couple of months (10 or so should do) and see what is in the market place. Post pictures, go to a PCA or Pelican get together. A well informed buy is better than jumping in feet first to test the water.

It may have been mentioned but, some early '83 cars (like mine 10/82) will have a sump plate at the bottom of the engine. Some of the SCs produced in '83 will not, i.e. they have a 3.2 carrera case.

SCs rule.

83 was the first year for a cab 911..

David

Let the car choose you.

Now that must be the most stupid advice I've ever heard.

Look around at a number of cars, choose one that looks in nice condition and is a nice color, then get a good PPI done that includes looking for broken head studs.

There's no great difference between the early SCs and the later ones, unless you're splitting hairs. Early SCs had wider engine intakes. Later ones had higher compression pistons but smaller intakes. The early ones are a bit lighter, but the later ones had somewhat better low and mid range power.

Horsepower and torque are the same for all models (sans smog equipment for the later ones, which sapped 8 horsepower). But you can make that up with driver experience...

They're all good. :)

You're all helping and I appreciate it. Now if Schuey would only answer my PM's. Take a look at Schuey's '83 SC and tell me what ya'll think. It's a long way to go, but if the car is right, the drive ain't nothin' to lose sleep about. Heck,,,,I've been looking for almost a year, and the stuff I see in So Cal is nothing to write mom about.

westy, i love schuey's car! i am going to look at one in concord tomorrow.

the changes from 80-83 were involved in trying to recapture the sheer magic of the '79 model year. Unfortunately they couldn't quite do it, and things really went downhill in '84...

ducking for cover...

Other things to mention:

The idler arm bases are wider in the later 3.0. That started in 80 or 81. That is very important to have. That idler arm base, in my eyes, is much more important for reliable chain tensioning than the oil fed upgrade. Even if you do the oil fed upgrade to an earlier engine, you must put the wider idler arm! Many oil fed tensioner conversions do not have that.

Nobody mentined the air pumps on the 78-79. Not an elegant setup. A belt and a gizmo under the decklid more to deal with.

Also, the way fuel is supplied at startup was changed in 81. Most of the backfire problems were solved by a metal insert to the air box that distributes extra fuel dumped in on top at start up to the runners better. A popoff valve is still mandatory even on an 81-83, but it's an improvement regardless.

The cams get a bolt in late 81 (this varies) instead of a nut. A superior setup, not in performance, but in ease of maintenance.

If you had equal cars of the entire SC year range, I would recommend you go for an 81-83. They were more mature. A feedback lambda sensor is a much more elegant way to take care of emissions than an air pump. Note that the lambda brain actually gives you the chance to tune the CIS if you use an innovate a/f ratio meter and wideband 02 sensor instead of the stock 02 sensor. You can measure a/f and then send an offset signal to the brain, having it enrich the mixture to optimize for performance! Can't do that on the 78-79.

If nothing else, an 83 SC will be 5 years newer than an 78! ;)

Cheers, George

You cannot go wrong with any of the SC's. There is a group of us that have from 79 to 83 and we take turns making performance changes. They all seam to run about the same with the same modifications. I wouldnt go past the 1983's though. The performance and dependablility really goes down after 1983. One thing we did notice as a difference in modifying the different SC's is that the SSI's heat exchangers seem to give the earlier SC's a little better throttle response than the later SC's.

yeah...too bad...but on the bright side, a '74 would be 4 years older than a '78 if you keep looking...;)
ryan

George is right, and I'm glad he posted. The vastly superior chain wheel carriers (idler arms) are on the later SCs but not the earlier ones. Also, the later SCs have 'hard' injector lines. I like them better. In general the later SCs are "improved" over the earlier ones, albeit subtly. But here's another thing to think about:

The earlier SC fuel system, with the larger intake runners, also have a different sensor plate, fuel distributor, etc. They lack the silly Frequency Valve which is part of the emisisons system, which only impacts idle anyway and has the potential to screw up. So, if you're going to unhook your O2 system (good idea), and particularly if you're going to want better pistons, then the earlier SC (78 and 79) are your best bet. A very slick upgrade is to put higher compression, HI PO pistons in the early SCs (less expensive if you have Nikasil cylinders). Apparently, they go like stink. Early SCs have good bottom end torque, or at least you can make them have very good bottom end torque (mine is very fun to drive as a street car because it has a power band like a V8), but an early SC with the J&E 10:1 piston upgrade will smoke me.

The earlier SCs (78-79)are better..... if you want to mod it to 300HP!! :)

The '78-'79 cars are also better for people who live in states that currently have a 25yr cutoff for emissions testing.

Lots of good info here. I would go for the 78-79 SC because of the larger ports and CIS runners. They respond better to upgrades than the later SCs, and they're lighter cars overall. On the other hand, Schuey's car is gorgeous. One of the best looking SCs I've ever seen. A good example of any of the years will be a real pleasure to own.

Sorry couldn't resist:
http://forums.pelicanparts.com/uploa...1081955052.jpg

I believe the late model (204Hp) Euro models use the early cars' larger intake runners.
81-83 Euro is the king of the SC's:D

Westy:

You could spend a few more dollars and hold out for the very, VERY late 83 SC with the factory "M3.2" Code. Like all of the "Porsche Specials", it did cost more. But, you got that same classic 911 with: bigger brakes for improved stopping power, a leap from the standard 180bhp to 207bhp, better gas mileage, and vastly improved performance (C&D Magazine tested the "M3.2" at 0-60:5.3sec, 1/4 mile 13.9 sec). These "M3.2" 911s were, in fact, the fastest production cars sold in America at the time!

The even later models ("M3.2/G50") got bumped to 217bhp.

The "M3.2" Code 911s were introduced to the public in late 1983 as the 1984 model Carrera and continued through 1989. They are distinguished visually by a "Carrera" script on the rear hatch. You may want to add them to your list

Why settle for the base model? Reach for the brass ring.

(flame suit on)

Mike

Mike,

You almost had me with that one! ROFLMAO!!

But, your weak Carreras will always fall to the SCWDP!!! It is written in the Book of Porsche, and The Gods have deemed it so!

(where is that flame suit....)

MOMO 3.2

If you're saying the late 83's had a 3.2, then it's not what I want. Thanx, but 3.0 for me or nothing. I've done waaaay too much reading on this motor to ignore it.

No flaming here. Carreras are nice cars, too. Just heavier and more complicated. SCs are more spartan, so I guess it depends on what a driver wants.

Jim (Superman), touched on an interesting scenario that I've been bantering around: a hybrid 3.0, which would be an '80 to '83 engine, but with early intakes from the '78-'79 3.0 that has its cylinder heads ported to match the intakes. Box this up with 20/21 cams, heat exchangers/headers or SSIs and a good muffler, and there supposedly is a substantial power increase.

I've heard this combination of early and late SC parts can yield over 240 horsepower. :eek:

I'd argue that the Carrera is less complicated. The Motronic system is more efficient and alleviates 90% of the problems that pop-up with the relatively complex CIS setup.

Westy:

That was all tongue in cheek. The 1984-1989 Carrera 3.2 is the "M3.2" option code to which I was referring.

On a serious note, I flat out love 911 SC's and would be every bit as pleased owning one as my 1987 Carrera. I was attempting to demonstrate that I have developed a sense of humor about posts like Nostatic made in this thread. It is in fact humorous reading posts that try to put a spin on the FACT that the SC is the base model, lower achieving brother of the Carrera 3.2.

It is kind of like a 914 to a 914-6, a 911T to a 911S, a Carrera 4 to a Carrera 4S, etc...

Mike

I've heard this, too. Which is why I might consider a 3.2 if I ever went through another engine transplant. It's just that little rod bolt issue which makes me hesitant, as I like to rev my SC motor up to 6,000 RPM more frequently than just "now and then."

DD74,,,,'splain your last post about the rod bolt, please

Westy

The rods in the 3.2 are supposedly weaker than those in the 3.0. Porsche did not enlargen the rods when the engine was increased from 3.0 to 3.2. They were, in fact, thinner than those on the 3.0. So at higher revs, they were more prone to failure on the 3.2s than 3.0s. This is one reason why many wrenches I've talked to like the 3.0 engine, particularly the later one with the turbo case over the 3.2.

dd74 -

Thanx. Once again, everything I read and hear points to the 3.0L . Heck, I liked my 2.4 (or was it a 2.2) with carbs on it. I'm sure the 3.0 will suit me just fine.

I find that 240 HP number hard to swallow when you compare those numbers with the factory built 3.0 RS of 1974. Those cars had big ports & valves, someone corrct me if I'm wrong, but a 9.8:1 or so compression requiring premium fuel, early S cams, MFI, a good free flow, tuned exhaust and they were rated at 230 DIN.

Regards,

Jerry Kroeger

"M3.2" at 0-60:5.3sec, 1/4 mile 13.9 sec?????

and over 240HP????? Yeeee! haaa!

Man, I'd be on my second beer by then!!

Go early, mod it up, go fast! :)

They're about 230 if the late euro p&cs (9.8:1) are used. Mine: 9.8:1, 964 cams, 78 heads, SSis, ansa exhaust (cheapo OEM 2 in 1 out copy). 195 at the wheels. Was 204 at the wheels with headers/open exhaust.

That was great! I have the M3.2 option and love it. :D

As someone who has worked on my particular 85 M3.2 car and many SCs, I would love for someone to explain the "heavier and more complex" comments to me one day, because I don't see it. They're nearly the same car, except for Motronic vs. CIS. And I doubt anyone will ever convince me Motronic is more complex than CIS.

The rods were redesigned in the 3.2 to make up for the larger stroke. It isn't the rods that are weak, but the fact that there wasn't room for a beefy enough rod bolt! This can easily be fixed with a $1600 set of Carrillo rods. :) Or for the street, just install some ARP hardware.

The other things speaking against the 3.2 is problems with valve guide wear. I do not know which 3.2s had this, but it sure was not an issue on any of the 3.0s. I know some folks with 150k mile 3.2 engines that smoke like chimneys. There isn't even an indication of such wear on my 3.0 with the same mileage.

I would not even THINK about putting a 3.2 in my SC. I would also stop attempting to get more out of the 3.0 as soon as I hit internals beyond cams. It's not worth it. If you are going to upgrade, go for a 3.6! Total cost may be about 3k over the 3.2 coversion or an involved upgrade (large p/c etc.) of the 3.0. I have ridden in 3.6 conversions. There is no replacement for displacement. And 250 horse is the plain jane 3.6 stock rating. It's fairly easy to get to 300 from 250. That's only 20%. :D

I agree that Motronic is much superior to the CIS. Just the reduced amount of clutter on the engine is nice. The CIS is just as reliable, however if you drive your car on a regular basis.

The SC remains the best bang for the buck on the current 911 market, followed by the 964 and the early 996. (All going up the price ladder).

Cheers, George

Westy, i believe that nice moss green SC coupe is still for sale at Jack L Hunt Auto in San Rafael, CA. Something like 43K original miles. Rare color, beautiful car. Asking around $18K. Give them a call.

i posted this awhile ago.
http://forums.pelicanparts.com/showthread.php?s=&threadid=150342&highlight=moss+g reen

Do you remember when I asked of <i>actual experience</i> on rod bolt failure. If I recall correctly one person replied with "I heard from a friend". I'm not saying it doesn't happen but it's less likely than some make it out to be.

Regarding valve guides, as mentioned a million times before, if it doesn't happen by 60k miles it's most likely fine for quite a while.

You ever feel like I opened Pandora's Box? OK guys, lets stop the arguing and FIND ME A CAR!!!!

I'll check the green one, but green realy isn't my color. Or at least that what my hairdressor says. Ooooops!!!!

Rod bolts don't fail like in snap. They yield / stretch. They don't stretch in daily use, even revving high, if you stay under redline. But what happens if you miss a shift at the track or on the back road? The assembly may see much higher than redline rpm. The pistons may not hit the valve yet, but the rod bolts stretch and end up a bit longer than they should be. Then the nuts aren't torqued any more and will come loose, slowly over time and before you know it, your bottom end grenades.

Will a 9mm bolt stretch quicker / more than a 10mm bolt? You answer that question! :D

It is splitting hairs. Back to finding a car: Buy any engine you like, 3.0 or 3.2, they are all very good. Find a car you like (color, condition) and buy it regardless of drivetrain. 78-89, who cares! :D

George

Westy- what about a C4? I saw a 110 000 mile coupe advertised for $16,000 :eek: