78sc engine wiring and injection control

[User-C3]

I have a 78sc that has been without an engine for quite some time. When I purchased it a few years ago it came with a renegade hybrids trans adapter and engine cradle for the LS1, and a 930 trans and clutch assembly. Since I already had an Ls on the stand in the garage I figured I would go that route. I have since changed my plans, sold the engine, and just last weekend purchased a supposedly fresh rebuilt 83 3.0 engine. I already have a crazy fast car, and want to keep this one relatively stock and just a fun driver that my wife can jump in and cruse whenever she wants.
My issue is because of the LS route of the previous owner there is no electronics remaining in the vehicle. The seller of the engine was nice enough to give me both the 83 intake/injection system as well as a complete 78 intake/injection system. So here is my dilemma. Do I go the route of sourcing everything to make the stock injection system work, go carbs with an MSD box, or all out and put together a custom efi setup and standalone. The efi would be the ideal, but I'm not trying to spend a ton of money and time getting it to work. I'm wondering if some of you wonderfully helpful pelicaners can help me figure out everything I need to make the stock system function and at what cost, or to just carb the engine. I should also state this is my first porsche and have no clue as to what should be there electrically. I've done some research so have a general understanding but just looking for input and some feedback.
Every bit is helpful and appreciated. A couple pics because everyone loves pics.
Also deliberating on whether I'm keeping the 930 trans or selling it because they are $$$ and getting a 915. If anyone has a good 915 with an LSD sitting around I may be interested.

[Flat6pac]

Pictures of the left side engine compartment. Include wiring harness, fuel lines, electronic control box,
Do you have oil tank?
Bruce

[Pazuzu]

Originally Posted by User-C3

I have a 78sc
supposedly fresh rebuilt 83 3.0 engine
both the 83 intake/injection system
complete 78 intake/injection system

Here's the main problem...
The 78 intake won't go on the 83 engine because the intake ports are different sizes.
The 83 intake won't go in your 78 car (easily) because whatever wiring you do have, won't be correct for the later, o2 sensor setup for the 83 engine.

What you DO have is a complete 78 intake system which would sell for several hundred dollars, and enough of an 83 intake system to turn into a stripped down Bitz or custom EFI system, and enough leftover 83 parts to sell for a couple hundred MORE dollars.

So, the $1500 basic EFI system is almost paid for with the parts you can sell. You have to custom wire anyways...


Or carbs. Sell both intake systems complete for about $700 each, and drop the $1000-1500 out of pocket and go carbs.

[timmy2]

Is the '83 engine US or ROW? Big difference as the '78 intake system will work just fine.
What wiring remains on the driver side rear?
You may even need a new through body harness!

[User-C3]

There are only a couple wires in the engine compartment, nothing else. It doesnt exactly look to be anything that would be hooking up to electronics. Nothing in the passenger seat location and I dont believe I have the through body harness either. No oil tank, but talking to someone local that has one and watching a couple on ebay right now.

What is the basic $1500 efi system your referencing to?

[Trackrash]

Nice project. Sounds like you are on the right track.

What is the wiring like in the trunk? How about any gauges? You should also post a picture of the wiring in the trunk.

Do you need to worry about a smog certification?

Here is what the engine electrical panel should look like. It is possible to fab your own if you have the correct wires, the ignition CDI and the CIS fuel module.
Relay ID - engine compartment

[timmy2]

Bitz kit is one EFI system that is relatively simple to install and reliable .
I've been running it on my car for almost 4 years. Haven't had to touch it once I got it dialed in.
The $1500 price is just for the basic kit, add another $1000 by the time you are done for the injectors, fuel regulator, and options like wide band O2 etc.

Post up a few photos of the engine bay.

[boyt911sc]

Originally Posted by timmy2

Is the '83 engine US or ROW? Big difference as the '78 intake system will work just fine.
What wiring remains on the driver side rear?
You may even need a new through body harness!

User-C3,

Please post the engine number located at the lower right area of the alternator mount. Looking at the picture of the '83 SC engine, it looks like it has the pre-'80-'83 CIS unit. Since you have two (2) different sets CIS units already, it would not take much to get this motor running.

Could you post a picture of the right and rear views of the motor? The plastic air box in the picture is broken and unusable. If your motor is a RoW model, it is a lot simpler to get it running with the parts you have now. However, if you have a USA model, you would need the ECU. Most likely a new set of engine wire harness, injectors, fuel lines, and CDI would be needed. Keep us posted.

Tony

[User-C3]

I took a few pictures last night. Car was up on the lift so I didnt get any of frunk area wiring, but believe if I remember correctly its all still there. It looks like the wiring is still there in the engine compartment but has just been cut. No gauges, but under dash wiring all seems to be there. Also have an original stereo in a box in my basement, if I decide to try and use it. I'm in the Detroit area so I dont need to worry about the smog cert, so that helps not limiting me on a decision. I have the engine number written down in my truck so will get that in a couple hours and post it.

[User-C3]

Here are a couple shots of the extra intake system

[User-C3]

Looking at the photos of both intake systems they basically look identical to me. Can someone tell me what the differences are between the 2 different types?

[boyt911sc]

Originally Posted by User-C3

Looking at the photos of both intake systems they basically look identical to me. Can someone tell me what the differences are between the 2 different types?

The '78-'79 SC have the larger intake runner ID of 38 mm and 34 mm for '80-'83 SC USA models. The RoW/ Euro ('78-'83 SC) all have the larger ID intake runners. So knowing your engine serial number would help. Remove one intake runner and measure the ID of the air box intake tube. The decel valve, AAR, WUR, and FD are also different for the USA SC models. A quick measurement of the intake runner OD would show the difference too.

Could you post the Bosch ID numbers of the WUR's and FD's on your CIS units? Thanks.

Tony

[Flat6pac]

The part number cast on larger tubes ends in 4R, the smaller tubes ends in 2R
Bruce

[User-C3]

Engine number is 64D4051

83 US 3.0 sc engine

[timmy2]

It appears the main front to rear harness has been cut removing all engine control wiring. Just the tail light wires remain. Rear fuse panel is gone too.

[timmy2]

FS: SC gauges, 964 tool kit, 964 cup holder
Gauges for a decent price in the classifieds. No affiliation.

[RarlyL8]

I have a 915 from my '78 SC rebuilt with WEVO gear that I will trade plus cash for your 930 tranny if interested. Also do CIS rebuilds if you find they are needed. We have a CIS Primer on our website Porche Enthusiasts Page that may help you with year specific info.

[pmax]

Originally Posted by User-C3

...supposedly fresh rebuilt 83 3.0 engine.

That engine obviously hasn't been run for a while and has the wrong CIS system and a busted airbox (really!!) on it.

Originally Posted by User-C3

I already have a crazy fast car, and want to keep this one relatively stock and just a fun driver that my wife can jump in and cruse whenever she wants.

Personally, I would sell the CIS systems and go modern EFI given reliability is a top concern and there's no smog issues. To go stock, you'll be spending money rebuilding the CIS components, replacing all the stock wiring, buying a new airbox and after a few months of fiddling, perhaps maybe end up with a reliable engine which will not blow up the airbox or have idling issues or fail to start when the weather changes. Why even bother ? The other pro for going EFI is lots more room in your engine compartment.

HOW many CORRECTLY running cars are there really?

[User-C3]

FS: SC gauges, 964 tool kit, 964 cup holder
Gauges for a decent price in the classifieds. No affiliation.

I saw this yesterday, very tempting, but trying to figure out everything I need and the most important order to buy everything. Thanks for the link

I have a 915 from my '78 SC rebuilt with WEVO gear that I will trade plus cash for your 930 tranny if interested. Also do CIS rebuilds if you find they are needed. We have a CIS Primer on our website Porche Enthusiasts Page that may help you with year specific info.

I may be interested in that trade. Send me a PM with amount your willing to put on top of the 915.
Thanks

That engine obviously hasn't been run for a while and has the wrong CIS system and a busted airbox (really!!) on it.

Thats correct, previous owner did say it has been sitting a while. I will be doing an inspection before running it.

Personally, I would sell the CIS systems and go modern EFI given reliability is a top concern and there's no smog issues. To go stock, you'll be spending money rebuilding the CIS components, replacing all the stock wiring, buying a new airbox and after a few months of fiddling, perhaps maybe end up with a reliable engine which will not blow up the airbox or have idling issues or fail to start when the weather changes. Why even bother ? The other pro for going EFI is lots more room in your engine compartment.

I do have the air box form the other intake, but even the cost of all the electronics to run this system doesnt make sense to buy when it would be the same if not cheaper to get a megasquirt and even piece together a sweet ITB setup. I do all my own work, so I dont have to factor in installation costs.

[targa44]

Where did you go? and... what did you decide to do?

thanks,

PM sent