Fronkenstein

Hey R'listers:

Ok so I've searched, dug and lurked and I cannot find a direct answer to a relatively simple question:

What are the differences between a US CIS versus and ROW CIS systems?

From what I have read thus far all I can find is ROW intake runners are larger. So Taking major components are there any differences in:

1) Fuel pump(s)
a) Are there always dual pumps (pre-pump) in 300+ HP systems?
2) Fuel accumulator
3) Fuel filter
4) System pressure regulator and topping valve
5) WUR
6) Airflow meter
7) Sensor plate
8) Throttle body and butterfly
9) Fuel distributor
10) Outlet nipples
11) Injectors
12) Intake runners

It would be great if we could get this answered in a single short thread. Especially for guys like me who are putting an m28.22 into a 1978 ROW car

Thanks,

Fronkensteen

ROG100

US CIS was only 78 & 79
ROW CIS was 78 to 83

US & ROW 4.5L 78, 79, 80, 81 & 82 practically the same
ROW 4.7L 80 to 83 - different cams, heads and spider - made the difference in HP

M28/22 was never a CIS engine it is LH-Jetronic 84 to 86 16v - lots of differences and more akin to a 85/86 S3 32v car

Fronkenstein

Ok well let's say I'm going to convert from LH to K Jetronic, which I am; what do I need to make CIS work?

ROG100

Top end - M28/11-12 spiders or convert the M22 spiders to take the CIS injectors.
My head hurts just thinking about what needs changing.
A M28/11-12 would be a much easier swap IMHO.

Fronkenstein

Unfortunately I don't have an M28.11/12 just kicking about. Hard enough finding the 22.

I guess I am just going to megasquirt the darn thing

The Forgotten On

You should have much less trouble than the CIS with it and you will get much better fuel economy.

Fronkenstein

Sorry Roger I didn't realize that was you On my Android and I dont see the sig or the avatar all the time.

Fronkensteen

karl ruiter

I know for sure that the throttle body, intake runners, and spider body are different and I think they have to be used as a matched set (i.e. you cannot connect euro S runners to a US spider body) I'm also pretty sure the WUR is a little different, at least as far as settings. I'm pretty sure the fuel lines, pumps, injectors, fuel dist can be mixed and matched. I think the dual pump thing is an attempt to make sure the car does not get vapor lock, which it does not anyway. Other, prior, Porsche models do, though, so I think they just wanted to make sure. If you are worried about sufficient fuel delivery there is a test for that in the WSM and if you meet the test spec you should be fine. If your short term mission is just to get a car that is running and on the road you can put either complete system on either motor.

Fronkenstein

Karl,

Thanks for the info. My intention is to go Mega eventually once Allan makes me some brackets and such. Until then I would like to run the can without leaning it out and losing a cylinder. I guess my AFR Guage will help me keep it from burning down.

Fronkensteen

Fronkenstein

So here is my interim fuel delivery solution for Inga until I can get all my MS3PRO stuff lined up :



Attachment 851246













So use your imagination. The great thing is that dimensionally the K vs LH injectors are very similar most importantly the diameter is equal. The mounting perches for the LH injectors make a very convenient place to hang a mounting rail. Using basic machine tools and some aluminum bar stock we'll be in business next week!

Oh and the WOT flow of the metering plate is plenty adequate to support the 90mm TB. The issue will be fuel flow but then again I'm not looking to hammer on her before she gets the MS3PRO. Just want to thresh out any chaff in the mechanicals.

Comments?

Fronkensteen

Fronkenstein

Euro RoW vs US CIS ;-)

danglerb

I love these, minor factory issue so I will "just" convert to megazquirt threads, but not in a good way.

Fronkenstein

Not enough info to understand your point. Converting the 78 RoW to LH-Jetronic was NEVER an option. To much hassle for no real gain other than to say it is "Porsche" and it is still wrong for that year car. If we're going for EFI in a 78 we're going mega.

However, if you will notice this is CIS and it is Porsche and it is bolt on. Better still it looks like it belonged there from day one to the casual eye.

Fronkensteen

hopwood

I have an M28/22 (Euro S2 LH-Jet 310hp) motor in my Euro 79 using the original CIS system. From memory it needed an "S" M28/11 spider, plenum and throttle body. Used original dizzy. Makes good power and torque (320hp with S3 manifolds and 3" exhaust). The M28/22 is a great motor.

Fronkenstein

Good to know!