Carl Fausett

Talking about the differences between the standard Euro and US (200 and 220 HP) CIS cars to the rare 300HP "Euro" CIS cars.

Most folks seem to know that the upgrades include the big-valve heads, camshafts, larger throttle body, and bigger intake runners.

But, we may have just found a little more. There were differences in the size of the fuel distributor outlet orifices too - they were small, but the fuel distributer for the 300 HP Euro definately had larger outlets.

This led us to inspect the individual fuel lines themselves. Look what we found!

http://forums.rennlist.com/upload/fuellines.jpg

Now, the injectors are the same (we checked Bosch part numbers), but the larger fuel line could possibly be a benefit during top-end and WOT.

Incidently, the Porsche part numbers for the fuel distributor and the injector fuel lines are also the same across these years and models. Yet, they are different. The product was changed without updating the item number.

Lizard928

do the new parts have the big hole in the end or the small hole if the part #s are the same

T_MaX

Heres another one for you

Take a look at a Mercedes Benz V-8 Bosch CIS fuel distributor and compare it to yours.

Carl Fausett

I know what you mean, Curtis. The Benz fuel distributor is adjustable for flow per cylinder for each of the 8 cylinders.

Like this: http://forums.rennlist.com/upload/ad...istributor.jpg

T_MaX

When are you going to drop one on a 928?

Look at how close the 84-85 MB 500 CIS system (Pre-CIS-E) is to the CIS system in your Porsche 928.

NOTE:see below post on 01-23-2004

Don Carter

Wonder why MB stuck with CIS so much longer than Porsche did. Obviously the "smart" systems were available from Bosche at the time, seems like they would have used them.

Lizard928

that would make tuning the merc a bitch

bcdavis

My guess is that Mercedes wanted to stick with what they thought was the most reliable, rather than what was better for performance, emissions, etc... CIS is pretty simple, and mechanical, rather than electrical. I am guessing that at the time, electronic engine management was just getting started, and they did not want to risk their reputation for reliability, on an untested system. Porsche, however, probably went with EFI sooner, because they wanted to use it to extract additional horsepower, and be on the "cutting edge". Mercedes is more conservative that way...

T_MaX

I think it's something to keep in mind as a possible retrofit for those with aging CIS systems.

Keep in mind that the MB 500 (5.0L) and 560 SEC (5.6L) came with an all aluminum V8 engine

bcdavis

I wonder if the Mercedes part is any cheaper?

The Porsche CIS fuel distributor isn't cheap...

Lizard928

due to the fact that the technology was discontinued and no longer made makes the price alot more

Jim Nowak

"Look at how close the 86-91 MB 560 CIS system is to the CIS system in your Porsche 928."

It's not from a 560. The 560 is CIS-E. The fuel distributor is from a CIS Mercedes V8.

"Keep in mind that the MB 500 and 560 SEC came with an all aluminum 5.0L V8 "

The 560 has a 5.6L and the 500 has a 5.0L. They also had a 4.2 and a 3.8L V8.

Ask me how I know:

Jim Nowak

Just so no one is confused........but they usually hear the blower:

T_MaX

Jim don't be so nit-picky, there is not that much difference between MB CIS and CIS-E in principle. CIS-E gives up some of its control to a few electronics boxes for better fuel economy and emissions.

Your right, 84-85 500= 5.0L (w/CIS) and 86-91 560 = 5.6L (w/CIS-E) sorry I mis-typed!

Hey Jim, I've seen that picture somewhere else, Hum? I just can't put my finger on it

You from Florida by chance?

Jim Nowak

Yep, from Florida.