3.0 sc engine swap 2.2
 

hi everyone,i have 1981 sc 3.0 with no engine and no trany,no engine harness...also 2.2 with 915 transmission and weber carbs laying around.im not that good on porsches,but mechanicaly minded so the questions are:
would sc fuel pump be ok for carbs with pressure regulator or should i change it?i have facet fuel pump for that engine ...
will brake booster operate normaly if i tape just 1 outlet each side or i need all 6?do i need check valve and vacuum tank?
also thats just long shot but would any off you guys draw me wiring connections out off sc pin plug?
would tacho work or i need to change it on early one?
do i need to change oil tank for what so ever reason or sc tank will do?
i have marelli distributor no vacuum advance
thats kinda it for now.any help would be cool.thanks in advance.

Stock SC fuel pump is high presure & will NOT work with carbs http://forums.pelicanparts.com/uploa...1352224488.jpg

thanks...the problem is i dont have any engine harness on 2.2 engine ,i hoped that someone might be able to tell me how i manage to make one. high pressure pump allright i knew that but if i put presurre regulator on the line ?
any ideas off the rest?

You can use the CIS pump on the carbs with the regulator (buy a good one, like PMO - dont go cheap) and use the return line on the system because that pressure needs somewhere to go. Quite a few people have done it on this site and you won't find a higher quality pump that FITS and lasts as long as this one. See this - instructions for PMO carburetor install including using the high pressure FI pump with a regulator:

http://www.pmocarb.com/installation.htm

You may still have the chassis harness that goes to the engine with the 14 pin plug. Alot of people stuff it behind the strut towers when they are doing a drop. You probably already checked, but thought I'd throw it out there just in case it was stuffed in with the sound deadener/dirt, etc.

angela

im afraid i dont have the engine harness...i will get a quality pressure regulator allright...you might think im stupid but do i need a pressure regulator with the return line connection or all of them has it?or should i connect the return line somewhere else?
would someone answer me the remaining questions?
thank you

You need a regulator with a RETURN line. They are made both ways (with or without). The PMO has a return line and even a gauge so that you can monitor the pressure.

SC tachs often do not work for the other engines (SC uses a different type of signal for the tach) and vice versa. I would try it first before commiting to replacing the tach. I didn't think it would work for my 3.2 motronic swap, but it seems to work fine, maybe you will have similar luck.

The wiring is going to be your challenge. If I'm reading your posts properly, the chassis harness is still there, but there is no engine harness for the 2.2 - which you have to make to mate to the 81 chassis - is that correct?

angela

good info from Angela.... I wonder if one of those aftermarket tach adapters could help matters? Like from MSD?

CIS pump works great and will only make about 2lbs of fuel presure without the CIS system. The PMO regulator brings the pressure up not down.

yes angela you got that right.i have complete chassis harness up to 14 pin plug in 81 sc.what i need to make or get is 70 2.2 harness .and then try to make it fit to sc pin plug.im gonna run webers at the moment so it cant be that much difficult to make the harness.later there is a plan to make it on tb's and ms with edis.i have another 2.4 engine with cis laying around with harness so i try just to eliminate cis wiring and will see how it goes.thank for your help.
buy the way green face gauge up to 8000 rpm.?what is out off?

Bosch FP.........
 

Vin-barrett,

A typical CIS fuel pump delivers atleast 90 psi. up to 100 psi. And the PMO fuel regulator reduces the extra fuel for carb application. Where the hell did you get this technical information? Keep us posted.

Tony

The system pressure is high because of all the restrictions in the CIS system itself. Once all that CIS stuff is removed you no longer have all that system pressure and you will only get about 2lbs even with the CIS pump.
The PMO regulator is not deadheading all that pressure down to 3-4lbs. It brings it up.

In other words the CIS pump "can" support high pressure but with carbs all the pressure goes away.

interesting...are the pressure regulator different in this case or one will do both ways?

Pressure is the resistance to flow, any resistance in the system brings up pressure.
Bruce

CIS and carbs use diffferent types of regulators. With the right fuel pump you can even run carbs without any regulator at all.
Sorry in advance if I didn't understand your question correctly.

no no i mean would any good quality regulator do or i need special one to get the pressure up?i would like to use sc fuel pump used for cis.i have naturally aspirated fuel pump but if i could keep the sc stock pump ....
the other thing that i need badly is to make wiring loom for 70 2.2t with webers that would connect to cs 14 pin plug and all the gauges would work...could someone help me....simple drawing on piece of paper will do.i cant figure out my wiring in the manual...i guess im just not minded enough.thats what i have in sc:http://forums.pelicanparts.com/uploa...1352776726.jpg

please help...i need my daily this friday

like angela said, any regulator with a return, the PMO brand as mentioned is your best bet. Sorry can't help with your wiring, although I bet you'd be miles ahead with buying a used harness one from a late SC in the classifieds. Especially if your trying to get this done by Friday... that's some deadline.
good luck

Man, that's going to be a wiring nightmare.
Using the 2.4 harness will probably be the easiest, but you will also need a 3 pin CD box and an early tach.

ok.regulator is not an issue.wiring on the other hand is...i spend few hours today on the diagrams...its seems to me its not that difficult.carburated engine has just two main things:ignition part of wiring and electrical part.i was able to figured out some...i will post drawing later on that you guys could take a look and correct me.also add what im not sure about...i think we will get that together...i mean is just the old car wiring....people landing on the moon ...

http://forums.pelicanparts.com/porsche-911-technical-forum/529476-cis-carbs-wiring-questions.html

http://forums.pelicanparts.com/porsche-911-technical-forum/575055-pmo-fuel-regulator.html

shane i saw this before...im not running msd not yet anyway...and don have any harness to butcher it.thanks anyway...
thats what i have come up with:http://forums.pelicanparts.com/uploa...1352863464.jpg
so far...
i dont need wire colors and sizes.just need someone electrically minded to confirm or correct if im wrong and add what is missing.

please please please

electical gurus come on ...is wednesday allready.i need car friday.please

FP pressure test........
 

Vince,

Do you realize what you are talking about? Have you ever pressure tested a CIS FP? This is a technical forum and such advise means you know it as a fact!!!!! Demonstrate that a good working FP delivers only 2 lbs. pressure and I'll buy you dinner for two!!!!! I spent a lot of time testing and checking CIS components including fuel pumps and I would say you are providing wrong information to the forum. Prove me wrong and I'll be more than happy to give you a free dinner and a public apology.

Tony

The pressure on the system is coming from the restriction in the iron fuel head.
You will indeed get an indicated 90lbs or so from the pump but only if you deadhead it.
If you loop the system like with carbs there will be no pressure like that because of little restrictions.
That little soda can sized fuel pump isn't going to make any kind of pressure unless you restrict the flow somehow like with the CIS parts, or deadhead it to a fuel pressure guage.
I think it's wonderful that you are testing these parts.

Thought I would add to this. Maybe I don't explain things well but I will do my best.

I did a search this morning on this subject and see that there is different thoughts on how the PMO regulator works.

Some people seem to think that the CIS pump will somehow push high pressure to the PMO regulator without any of the CIS system's restrictions, while somehow(?) the PMO regulator brings down the pressure to 3-4 lbs to run the carbs. That would be quite a feat for that little box.
Tony, you mentioned this in this very thread.

This is not how it works.

Like I've said, when you recirculate the fuel with the PMO regulator it's just looping back to the fuel tank.
And yes it will be around 2lbs.
The PMO regulator is pretty simple. It just connects the feed and return lines. At the return back to the tank there is the adjustment screw that increases fuel pressure. Tighten the screw down and pressure goes up.
Loosen the screw out all the way and the regulator does nothing. Doing this will show on the pressure guage ......yes about 2lbs...and yes with the CIS pump.

Im sure with all your experience testing you can understand why there is little pressure when the pump is not restricted with the CIS system in place. It's pretty grade-school logic actually. I'm sure your a smart guy that maybe put more effort into acting like a dick on the internet than thinking about what people are trying to tell you.

Here's a couple of threads I found for you.

Post #11
http://forums.pelicanparts.com/porsche-911-technical-forum/594417-adjusting-pmo-fuel-regulator.html

Post #19, 22, 27
http://forums.pelicanparts.com/porsche-911-technical-forum/575055-pmo-fuel-regulator.html


http://forums.pelicanparts.com/uploa...1352989952.jpg

Sorry buddy, you owe him dinner and a public apology.
I recently installed webers on a 3.0 using the existing cis fuel pump.
With the PMO regulator wide open, the pressure at the regulator was ~2 psi.
I cranked down on the regulator restricting the fuel flow until the pressure increased to 4.5 psi.

Pressure gets created by restrictions.
How could a CIS fuel pump deliver 90 psi without any restrictions?

it seems my thread became battle field...ok...i dont mind, only in discussion you gonna get some results...
but could someone fight about the wiring please... :)

You guys are correct!!!!!
 

Vince,

After further review and reading about the PMO regulator's function you are indeed correct and I was mistaken (wrong). Please accept my apology for contradicting your statement. I will PM for your address. I like people who could educate me. Thanks.

Tony