A Quiet Boom

I finally got my 3.0SC engine today, and although its complete the harness was cut where it goes into the inside of the car, the harness for the smog computer is intact though. I have the haynes manual but the wiring diagrams are vague and hard to read at best, anyone know of a better diagram?

On another note is there any downside to removing the smog computer entirely, installing MSD in place of the CDI box and only hooking up the remain necessary wires to my 1969 harness (i.e. sensors, etc.) This would greatly simplfy installation for me and my plans call for aftermarket efi over the winter anyway. Besides I have an MSD 6al just sitting on a shelf in my basement.

Lastly, I'd like to temporarily use the 901 trans, will I need to swap clutches? it looks like I will.

As always any help is appreciated.

Chris Martin

Your swap is a little over my head, but there is a faq on the msd installation on pelican: <a href="http://www.pelicanparts.com/techarticles/mult_MSD_install/mult_MSD_install.htm" target="_blank">http://www.pelicanparts.com/techarticles/mult_MSD_install/mult_MSD_install.htm</a>

The Bentley manual for the SC has very good wiring diagrams as well, highly recommended.

Jeff Curtis

I took the O2 sensor and computer out of my SC a long time ago...it ran like a scalded dog! I constantly monitored the CO2 level and kept it around 2%.

The box I removed was the one underneath the passenger seat, and converted to Euro CIS...also had MSD, but eventually went to the Electromotive HPV-1 Crankfire ignition.

Your MSD 6AL will work great...as that is what I had.

Just don't run an O2 sensor and remove the box.

As far as using your 901 gearbox and changing the clutch...you may have pressure plate to flywheel issues - also the 901 uses a completely different clutch release mechanism. I'm not sure what a complete conversion would entail, or even if it's feasible. <img src="confused.gif" border="0">

A Quiet Boom

Thanks much, I'd really rather not screw with all that stuff for the stock CDI and smog computer. As far as the clutch goes if I can bolt my 901 clutch to the SC flywheel I assume I can make it work, the problem I'm having is fitting my late 915 into my shortwheel base car, I need a way to adapt the CV joints and of course a new electronic speedo. The 901 would get me by until winter when I can really dig into the car and do it right including aftermarket EFI. When you say Euro CIS what does that entail?

1980SC

The CIS fuel distributor that is on your motor requires the O2 control box to operate the frequency valve. The car will not run well at all without that control box. The european CIS is like the USA '78-'79 CIS, and does not have a frequency valve in the fuel distributor. I would replace your CIS with the euro or US '78-'79 version if you want to lose the O2 crap.

Rob
1980SC euro

Jeff Curtis

Well said Rob...I'll leave it at that!

A Quiet Boom

So what parts would I need to convert to euro-spec, just the fuel distributer or is it more involved than that?

Tom F

I think that you can run without the oxygen sensor, just fine. I don't see any problem since you've got an emissions exempt car. Also, I don't agree that you can't run the original fuel distributor without the lambda system.

1980SC

Entire CIS systems can be found forsale because their engines are often converted to carbs. Tom's statement above regarding the use of your fuel distributor without the lambda system is incorrect. You can leave the O2 sensor off, but without the computer, relay, and harness, your control fuel pressure will be way off.

Rob
1980SC

A Quiet Boom

If I wanted to sell my entire CIS with the brain, Bosch CDI box, wiring harness etc. what would it be worth? I'm considering this so I can just pop some webers on it until I build my EFI system. Another alternative I have is to buy a complete 3.2 EFI system from my brother.

Jeff Curtis

Tom, Rob is correct in saying that you cannot run his original FD without the Lambda Sensor...but please forgive me as I owned my modified SC during a period in which I DID NOT own a digital camera...so I'm going to go from memory here...although I own several manuals for the car, Bentley, Haynes, Bosch CIS "Bible", etc.

...but at present, I am at work - and believe it or not, that's when I do my best work...on Rennlist, and for my company.

If I remember correctly, there is a third inlet for fuel, that is controlled by the frequency valve that is "inline" with the fuel supply...although I may be wrong.

I recall undoing this mess, leaving the frequency valve, which is an electronic injector for all intensive purposes...just hanging...I didn't even have to cap the line off.

I just installed a Euro FD and WUR and wallah! I then paid close attention to my air/fuel mixture as I knew this would be important at this point.

I kept it around 1.5-2%...and it ran like a scalded dog - as I like to say.

I also had an enlarged throttle body, Webcam 20/21 grind performance cams, a FULL B&B setup, headers and all...and an Electromotive HPV-1 SINGLE plug ignition setup, fired off the crank pulley...distributorless!

So, Silent Boom, all you need is a Euro FD and WUR...the correct Euro CIS SCs had larger intake runners and larger intake ports on the heads...but I wouldn't worry too much about that as it would hurt your low end torque quite a bit.

A Quiet Boom

Hmmm, been looking on Pelican for CIS parts mainly the FD, I didn't find a Euro one though. Also what is the WUR? All in all it seems like a lot of money to spend on something I'm going to remove over the winter in favor of EFI. I'm thinking at this point to just install the CIS as is and start building the EFI system. For the cost of EFI (around $2000) will I see much gain vs. your method? Gotta bug ya for one more question though. I need to sell my 2.0 engine (or wife will kill me) and I'd get a better price with the headers left on it. I was looking at the exhaust on the 3.0 and thought about a cat bypass pipe. Can I expect much HP increase with a cat bypass vs. early style "dual" exhaust headers?