CIS Guru Question

[Pkaaso]

Could someone please explain a few things regarding 78-83 US and ROW CIS parts usage.

1. Did Porsche use different metering plate assemblies for U.S. and Euro?
Or, did they use the same one for all these years?

2. Did Porsche use different Fuel Distributors between the U.S. and Euro in 78-79 and on thru 83? Has anyone figured out the part numbers?

I searched Pelican's PET but didn't find part #s on the metering plates, and I've been told conflicting info on the FD.

Why I'm asking:

I started with a U.S. 81' 3.0 engine. My goal was to get as close to a 78-79 Euro motor as my budget would alow. I changed out the stock runners/airbox with the large (78-79) ones. I ported the heads to match. The fuel distributor was a xxx.031 (I believe is from a 78-79) the W.U.R. is a xxx.045 which should be a match.

The car runs very strong at this point but is leaning out as the RPM's increase. I'm thinking that the metering plate (stock 81') is not right unless they are all the same.

Thanks in advance for any information,
Paul

[Bobboloo]

Not a Guru here but I have heard from a respected P-car mechanic that CIS motors have a tendency to go lean in the higher RPMs.

[munsonbw]

How do you know it is going lean? I am no expert, but I have a '81 ROW that I have recently done a head stud replacement. In the process of tearing it down, I went through the parts to learn more about the motor that I have. What I found is that, contradictory to BA and Wayne's books, all ROW cars had 39mm intakes and ports. Since your US car is an '81, you should have 9.3:1 compression. I would say you need to try and replicate a 930/10 motor, i.e. a '81-83 ROW, not a 78-79 ROW... or at least somewhere in between (looking at compression ratios). Have you thought about adjusted the cam timing? As I understand it, the cam timing, higher compression, and 39mm runners and ports all contribute to the extra 24 hp. You are mostly there with the 9.3:1 CR and 39mm ports. Adjust the cam timing and you should be getting a little better top end power.

Back to your specific questions 1 and 2. I am sure the FD is different between the '81-on cars, but I can't remember if it is for 78-79. I think so. I have my CIS off of the car and would be happy to verify any part numbers to compare with yours.

[boyt911sc]

Never been a CIS Guru but starting to understand the principle......These data were taken from the Bosch Parts Application Table and might be of help.

Fuel Distributor------Application --------- Notes

0-438-100-010------- '76 - '77 ------------ 3.0 liter Carrera (Euro)

0-438-100-031------- '78 - '79 ------------ SC

0-438-100-031------- '80 ----------------- SC (until June '80)

0-438-100-097------- '80 ----------------- SC (July '80 on ward)

0-438-100-097------- '81 - '83 ------------ SC

Not exactly sure but it might be also applicable to '78 Euro (if any). Hope these help some readers. Thanks.

Tony

[Scott R]

Originally Posted by Bobboloo

Not a Guru here but I have heard from a respected P-car mechanic that CIS motors have a tendency to go lean in the higher RPMs.

Not sure if they really do, this is my 80' on the dyno

[munsonbw]

Just confirmed my 81 ROW fuel distributor to be a 097, if that helps any.

[1982911SCTarga]

Tony, I think the last three digits on a '81-'83 U.S.-version fuel distributor should be 077.

Brian

[Jim Williams]

Ben,

Don't forget to check the Bosch number on the airflow sensor housing on your '81 RoW engine, and pass that on as well.

Also, you should find that the Warm Up Regulator will have the part number xxx.089.

[Gunter]

Originally Posted by boyt911sc

Never been a CIS Guru but starting to understand the principle......These data were taken from the Bosch Parts Application Table and might be of help.

Fuel Distributor------Application --------- Notes

0-438-100-010------- '76 - '77 ------------ 3.0 liter Carrera (Euro)

0-438-100-031------- '78 - '79 ------------ SC

0-438-100-031------- '80 ----------------- SC (until June '80)

0-438-100-097------- '80 ----------------- SC (July '80 on ward)

0-438-100-097------- '81 - '83 ------------ SC

Not exactly sure but it might be also applicable to '78 Euro (if any). Hope these help some readers. Thanks.
Tony

Are these Euro numbers?
Bosch USA states that the US '80-'83 SC's have 0 438 100 077 fuel distributor; the '78-'79 have 0 438 100 031.

[Gunter]

Originally Posted by Pkaaso

Why I'm asking:

I started with a U.S. 81' 3.0 engine. My goal was to get as close to a 78-79 Euro motor as my budget would alow. I changed out the stock runners/airbox with the large (78-79) ones. I ported the heads to match. The fuel distributor was a xxx.031 (I believe is from a 78-79) the W.U.R. is a xxx.045 which should be a match.
Paul

Paul:
The WUR and FD match for a US '78-'79 CIS.
Since you ported the heads on the '81 heads to 39mm, I suggest that you time the cams to 0.9 - 1.1 mm.
That will match your '78-'79 CIS and give you some extra HP with the 9.3 : 1 CR.
The cam timing on a US '81 engine is 1.4 - 1.7 mm.
You may also consider re-curving the distributor; the '81 distributor is too advanced in mid-range RPM.

[Pkaaso]

Very cool guys.

"Air Flow Sensor" This is the name I was looking for. This houses the "Metering Plate."
Part numbers for the different (IF DIFFERENT) Air Flow Sensors, is what I'm looking for.

Bobboloo: I have heard that too so I checked before beating up the motor on the track.
MunsonBW: First ran it unloaded on a smog machine and got very lean #s.
I then ran it again (not completely warm) loaded (wheels on dyno) and got this:
HC: 126,
CO: 0.13
CO2: 12.90,
NOX: 435
02: 2.70
@ 3 - 4 Grand RPM's

I did this just before closing last night next door at the smog shop so just a quickie.

I guess the better way of stating my intentions would be:
I have an 81 U.S., I had the Euro/larger runners/airbox, the F.D. x.031 and the W.U.R. x.045
I ported the heads to match the runners. I believe they are 37mm but you may be right on that and the 9.3:1 compression.

My concern is that the lean condition is coming from the possiblity of the "Air Flow Sensor", or "Metering Plate", or the geomitry inside the part is different from the 78-79 and the 81 that I have. i.e. bigger throats, plates, ratio of plate movement to F.D. plunger/rod movement.

Thanks and YES, what are you F.D. and W.U.R. numbers? The wur # is a little hard to see so don't go nuts for me.


Boyt911sc:
Thanks for the parts #s. I'm trying to determine if 78-79 EURO used the .031 as the U.S. Model. I have been told 2 different things.

1. Euro used the .031 in 77-83 and U.S. only used in 78-79 then switched to the .097.
2. Euro used an exclusive F.D. (part # unknown at this time) for the 77 - ?? (83 im guesing)

It's this "unknown" F.D. that is suppose to be very rare and no one really knows about it.
ANY ONE, Bueler, Bueler....

ScotR:
Thanks for the #'s
My guy next door does not have the dyno capability on his smog machine. SUCKS!

1982911SCTarga:
This backs up my theory on the "EURO" using .031 77-83 and the U.S. switching to the .097 in 80.

Jim Williams:
Yes, numbers, numbers, numbers. I don't have my numbers (yet) off my air flow meter. But, will next time I'm in there.
Also, I want to research the .089 F.D. in Porsche's PET.


Thanks all for replying.

Paul
P.S. I WILL get a pic of the engine and post ASAP.

[Pkaaso]

Gunter...

Posted same time as yours. GLAD to hear from you. I was hoping you would jump in. Thanks for your past help and the car is still running very strong.

Cams timed when I was building. Spot On the #s there.

Check my last post.
I'm off to San Diego to spend the night the Air Craft Carrier with the kids. So, I'll check back tomorrow.

Thanks everyone
Paul

[MBEngineering]

HI Paul
some thing for the weekend for you to translate, could be of some use to you ?????

[munsonbw]

Originally Posted by Jim Williams

Ben,

Don't forget to check the Bosch number on the airflow sensor housing on your '81 RoW engine, and pass that on as well.

Also, you should find that the Warm Up Regulator will have the part number xxx.089.

I was afraid that I was going to have to get the number off the plate itself... but found the number on the housing.

Air metering housing = 0438 120 143
WUR = 0438 140

Jim, this doesn't jive with what you were expecting. I'll have to dig tonight and see what this means. I just took a lunch break from being arms deep in a rebuild of the engine.

[MBEngineering]

and the rest,





the photo is not to good on the one below and the righting also, if you think it could be of any use let me know and I will see if I can make a better copy.







regards mike

[Pkaaso]

MBEngineering
Are these Euro numbers? This supports that the F.D. was the same on 78-79US and Euro.

Is that what I'm seeing?

Paul

[Pkaaso]

MBEngineering

I posted before your second post showed up. WOW! Yes indeed time to translate.

Anyone Sprecezy Duoich?

Paul

[MBEngineering]

HI Paul
I hope thay are , as I am quite a way from you and I work on "EURO" cars most days(7).
if you need any more info , let me know .

regards mike

[Gunter]

Me thinks:

Mengenteiler = FD
Luftmengenmesser = Airflow Sensor housing
Warmlaufregler = WUR
Bosch Kennzeichen = Bosch numbers

Most of those numbers look like Euro

[boyt911sc]

Originally Posted by Gunter

Are these Euro numbers?
Bosch USA states that the US '80-'83 SC's have 0 438 100 077 fuel distributor; the '78-'79 have 0 438 100 031.

Gunter,

The data were taken from a Bosch Application for 911 (specific to engine designation). The info I furnished are very similar to MBEngineering's data. The CIS components for my '78 Targa (US version) are the same as specified in the Bosch Application Table (the table includes FD, CSV, WUR, AAV, fuel injectors. fuel pump, etc.).

Please refer to MBE's info and it will show a column for early & late SC's FD as -031 and -097 respectively. Same as the Bosch Table.

Tony