Thoughts on a 3.0 SC engine in a 1970 911E

[BobNorman]

I’d love to find a 2.2 MFI. For it, but this car needs a lot, so the budget just isn’t there for the proper motor at the moment. Here she is:

[BobNorman]

Well, I bought the engine today. Not sure what I’ve gotten into, but bit the proverbial bullet anyway. He decided to keep the transmission, so I got it for less than I was planning to spend. Comes with the carbs and oil tank. Missing the distributor, one intake manifold, carb linkage and exhaust. I’m sure I’ll find out more stuff I need. On a steep learning curve now. Engine turns, valves move, so I guess that’s a good sign. Plugs are out, have been since the engine last ran about 3-4 years ago. I’m going to clean it and then come up with a plan. Full tear down? Just pull the heads? Try it start it as is (after installing missing bits)? See how it runs and then tear it down?

Me nerves.

[BobNorman]

All right. Day two. I cleaned it up a little, it’s looking pretty good…she’s a sexy beast for sure. Not that that means much.

However, I did manage to find the previous owner of the car it came from. He told a friend of mine that he had a bunch of work done to this thing just before he sold it. He said he spent about $7500 on it including the carb swap, and had replaced the cams. I’m not sure what else he did yet. But apparently the engine was running really well, my friend actually drove the car about 4 or 5 years ago, just before it was sold. All that said, I paid $3500 for it so I think I made out pretty well.

Also, he still has all the FI gear in his attic. So I guess that’s an option. For now I’m going to seek out the missing manifold and distributor.

Suggestions on what to be looking for in a distributor ?

[H-viken]

Originally Posted by BobNorman

All right. Day two. I cleaned it up a little, it’s looking pretty good…she’s a sexy beast for sure. Not that that means much.

However, I did manage to find the previous owner of the car it came from. He told a friend of mine that he had a bunch of work done to this thing just before he sold it. He said he spent about $7500 on it including the carb swap, and had replaced the cams. I’m not sure what else he did yet. But apparently the engine was running really well, my friend actually drove the car about 4 or 5 years ago, just before it was sold. All that said, I paid $3500 for it so I think I made out pretty well.

Also, he still has all the FI gear in his attic. So I guess that’s an option. For now I’m going to seek out the missing manifold and distributor.

Suggestions on what to be looking for in a distributor ?

Based on this, you did well!

Just buy a stock SC distributor, put a WTB ad here in the sales sections.

If the cams have been changed and the engine is otherwise healthy then clean it up, service it and the carbs. Put it back together and enjoy. Will be a fun package!

[faapgar]

The carbs have the taller diffusor from 46mm.Might be 46mm.You have done well.Ciao Fred

[BobNorman]

Thanks guys,
So, I’ll looking for a stock SC distributor. Not a distributor that would have come with these carbs originally. Were all the SC’s the same? Is there a particular number I should be on the lookout for? I’m assuming I’ll have to get it recurved.

I did notice the taller diffusors, hadn’t seen them on Weber 40 IDAs that I had googled so I was wondering about that.

They are stamped 40 IDA 3C1, so I’m not sure why the diffusers are like that.



Can anyone tell me what these carbs would have been used on based on that number? Thinking it would be nice to know as I go searching for the manifold and linkage.

Also, with regards to the missing manifold, is there any difference over time, or will any Weber 40 IDA manifold do?

Thanks again for all the helpful comments so far, as mentioned I’m new to Porsches, and on a learning curve here.

[drewr]

Fun project! At $3500, I think you did very well. Unless there is some serious unknown badness, the engine case alone will be worth that pretty soon!

Keep us posted on the project.

[Trackrash]

Congrats on your project. You will be happy with the results.
Here is my '71E with a carbed 3,0 SC motor. See my garage for more details.

[T77911S]

3500 for the motor was a good deal,.

send the carbs to 1quicks and have him rebuild them .
or as others said, go efi.

I love CIS but don't go that route. that car needs carbs or EFI.

the car itself is worth a lot,.
what ever you do don't go cheap.

I love green .

[BobNorman]

Thanks, yeah, I think I did ok on the motor after all, particularly with what I know about it now!

As for induction, I think carbs it is from the sounds of what I’ve read here. I could get the original CIS system back but it seems like performance could be better with the carbs and I like the old school look. Even though the car is an E so MFI would be more appropriate, I think between CIS and Webers, the carbs suit the car more. As someone said, I’m going caveman with it.

As for the car, I’ve always wanted an early 911 or 356, and this (project) is the only way I could ever afford to get one, at least if I wanted to stay married, which I do.

My plans? Well, my garage moto is: FAST, INEXPENSIVE, WELL DONE -Pick Any Two. Similar to that, and based on what I can afford, this build won’t be fast, but it will be well done.

I do want to do the car right and as correctly/stock as possible. Car was "updated" in the 80s or 90s, but I have been accumulating replacement parts for the past 9 months, and have about 75% of what I need, including rust replacement panels.



I’m currently halfway through another project that needs my attention though, so this may have to wait in its small corner for another year or two.

[BobNorman]

Originally Posted by Trackrash

Congrats on your project. You will be happy with the results.
Here is my '71E with a carbed 3,0 SC motor. See my garage for more details.

That looks fantastic!! I'm sure I'll be approaching you for more pictures and advice as this progresses. Cheers!

[Flojo]

show sidepicture auf flares at rear please.
was it just SC-updated or proper RS-widenend
the RS edge of flare is indeed different than the SC/Carrera flares.

further, was it upgraded to Aluminium/SC- trailing arms?
if yes you may rethink to backdate to narrowbody.
a) wheels will stand out (track width)
b) you won't fit 8s or 9s under a narrow flare anymore (with regular et10/11 or 15)

what about brakes? was it upgraded to SC/Carrera brakes?

both a possible brake and trailing arm upgrade are a plus if running a tuned and carbed 3.0 with possible 200+HP

[911hutch]

Instead of buying a SC distributor and sending it out to have it recurved ( unless you find a 78 - 79 ROW distributor) you might try to buy a used Electromotive single plug crank fire set up.

Since you probably have a cam with specifications (you should check the end of the cam for a designation/identification stamp or take physical measurements, important info you would want to know) designed for carbs and you have carbs already set up (correctly????) for the engine I wouldn't even consider reverting back to CIS for an early car application. Your current parts should make for a pretty close to plug and play induction scenario.

[BobNorman]

I don’t think this car was turned into anything special when it was updated in the 90s. The car did come with this Momo? steering wheel though.


Hard to see the fender flares where she’s currently boxed in, but here they are:






I really wouldn’t know what the difference would be. Also here is a shot of one of the rear trailing arms. Looks like steel to me.



I’ve gone back and forth about the rear flares, I want to put the car as close as I can back to stock where feasible, and I know it would be worth more as a “correct” car, but I have to say, the flares have really grown on me.



I love those hips!

[BobNorman]

Found another side shot showing one of the rear flares.

[BobNorman]

A call for advice once again. I thought I’d just post it here rather than starting a new thread.

I’m getting ready to install the engine in the car. I have secured the proper clutch plate and disc to mate the 911 transmission to the SC motor, and have gathered pretty much everything else that I think I’ll need.

I have a wiring harness and fuse panel from a 1970 911S, and have mostly sorted out what wiring is needed. With no FI system things are much simpler. I do have a distributer from an ROW SC, which I’m told will work well with the carbs.

The only thing I’m confused on is the CDI. I was told somewhere along the way that I would need a 6 pin vs the 3 pin that the car would have come with. I have a 6 pin unit, but am unsure how to wire it up to my existing set up. There are two wires (Blue/Yellow & Brown) in a three pin female connector on the panel which I think go to the old (3 pin) CDI unit.

I guess my question is twofold:

1. Do I need the 6 pin CDI, or can I just use the 3 pin that would have played well with this harness?

2. If I have to use the 6 pin unit, does anyone have a simple wiring diagram to show me how to wire this? I have the two wires in the three pin female plug mentioned above, I also have the green wire from the SC distributor, that I know comes into play, and I know there would be a red power wire in there somewhere, as well as a wire from the coil. On my engine harness I have a purple black wire that the 70 wiring diagram tells me goes to the distributor, and then to the tach? I think this come into play as well.

Any advice here from anyone who may have done this before is most welcome.

Thanks,
Bob

[Trackrash]

Yes, you will need the 6 pin CDI to match the distributor. I am assuming the euro dizzy has the magnetic pic-up and not points. Two different technologies.

You will need to create a new ignition harness and re-do the wiring below the engine compartment electrical panel. Including re-doing those 14 pin connectors to do it right. Porsche changed the way the CDI box was wired to the dizzy between '71 and '78.

I did a write up on this many years ago. I'll post the link when I find it.

I can post the wiring for the 3 pin, but it will do you no good.

The HOPEFULLY you have the tach adapter on your car. If so you can just wire your tach to the coil and your original tach will work.

The silver can to the left is the infamous "tach" adapter used only on '70.

[Trackrash]

http://forums.pelicanparts.com/porsche-911-technical-forum/946047-14-pole-connector.html

http://forums.pelicanparts.com/porsche-911-technical-forum/982031-82-engine-into-71-ignition-wiring-questions.html

[Schulisco]

Bob,

here you'll find the wiring diagram of different 911's:

https://classickabelboomcompany.com/wiring-diagram-porsche/

If you want to stay with the stock SC distributor then you have to stay on an ignition box capable to handle with inductive pickup. Porsche introduced CDI on the 911 in 1968 afaik to make them more reliable. But in the beginning the ignition was triggered like with normal breaker setup. These were the 3pin boxes. Inductive pickup came with the SCs and 6pin boxes. Either you change the 1970ies wiring harness to use the 6pin CDI box or you change the whole ignition.

In general the engine itself can be managed with breaker or inductive pickup, this makes no difference. It's more a matter of your personal choice and what you want to achieve. Is the SC dizzy in good condition, does it still advances and retards as it should? Did you checked it yet?

The 3pin CDI box won't work with the SC dizzy because the 3pin boxes are managed as a breaker ignition as said. SCs started to have inductive pickup from the beginning. You can replace the 6pin CDI box to e.g. a MSD6 or Permatune box or similar. But the SC dizzy is always inductive pickup. The MSD6 can operate either with inductive or breaker setup.

I personally use an 123ignition tune USB version dizzy with a Permatune box. My 123ignition dizzy is the older version with a breaker setup intended to be used on 911's up to 1977. I use it with a Permatune 3rd gen GS (=general service) box which is basically a breaker triggered CDI box being used in many other vehicles too.

You can waive the CDI box when using a 123ignition and connect the tachometer to it's output and 123 coil, but then you have to protect the tachometer, beause the bursts coming from the coil will damage it for sure (you connect both on output of the dizzy). The spark of the combo 123 with a fitting coil might be as strong as them from a CDI by todays standards (IGBT FET transistors simply switch faster/quicker than older simpler tranisstorized ignitions).
My choice was to stay with CDI paired with a modern and programmable ignition curve beause of some changes on my engine, see my footer. Pretty happy with that.

Thomas

[Trackrash]