82-T/A

Hey guys,

Sorry to create a new thread about this, but I was hoping to attract the attention of you CIS guys. I'm looking to buy a 928 sometime by April of 2008. I've narrowed my decision down by a couple of models. One of the models I am very much considering is the 78-79 with CIS injection. I've got some experience with that type of injection system because of a couple of older Volvos that I had.

I really like the system, and as I mentioned in another thread, it's the "beauty in simplicity" so to speak. Now, I'm aware of the rather painful timing belt setup... but that's something I just have to deal with regardless of which one I decide to buy.

1 - Other than that, how would you guys say the CIS on a Porsche 928 is different than that of a Volvo 240?

2 - Does it still use that same simple fuel distributor w/ air valve to meter the fuel? Is there still the same fuel pressure adjustment screw?

3 - What kind of performance could I expect from a totally stock 78-79 928 with CIS? How about a Euro Spec one?

4 - Is there any reason why I could not take a 4.7 (or maybe a 5.0) Porsche motor from the junkyard or off eBay and drop it into a 78-79 and use the CIS injection on it? (and just boost the line pressure)?

5 - Were there any major improvements from 78-85 in terms of suspension and transmissions. If so, can I easily swap them over?

6 - One last question which is about 928s overall. Several years ago I saw a 928 in the junkyard (looked like an early 80s) and it had split dual exhaust (an outlet on each side). Was this custom or was it some sort of an option? I haven't seen another one online that had this?



Thanks guys, I really appreciate any adivce.

hacker-pschorr

I doubt any parts are interchangeable
It works the same, not the same unit.
That has been done already - so yes it is possible
I don't see any advantage to CIS over L-Jet that would cause me to buy a CIS car and swap over all of the "S" suspension and brake parts from an 83-84 car. I would rather have an 83-84 car if that was my goal.

I'm yanking the CIS off my 79 hopefully this winter. It works fine, it was completly rebuilt a few years ago.
Why am I dumping it? Parts are getting impossible to find. Since this is a track car I would rather have a setup where there is a good supply of spare parts.

Vilhuer

Major gearbox change to '85 MY. New style much better syncro rings. This can not be mounted into '78-early '80 MY without changing or modifying torque tube.

Custom setup. All stock exhaust exit on left only. There is fuel tank in other rear corner so puting exhaust in there is not smartest possible idea.

'82 MY US cars had "S" suspension and brakes. ROW 4.5L got them in middle on '80 MY already.

If CIS is must then I think '80-83 ROW S is best option. It has "S" suspension already. Finding one worth buying takes some luck.

Airflite40

1. Most CIS systems I have seen on old Audi's and Merc's and the Porsche 928 CIS system are essentially the same. The components change size and such, but they all pretty much have a air metering plate, fuel distributor, warm up regulator, a cold start valve, and the mechanical injectors. EDIT like Enzo said.. not interchangeable

2. Yes, not sure about the fuel pressure screw, since I never messed with mine... didnt get that far.

3. The 78-79 engines put out 219hp/245tq in stock form.... the Euro ones get 229/250 but this is mainly due to emissions equipment. Best bet for the 78/79s is to get headers and a free flowing exhaust.

4. You can build a hybrid with a 4.7 or a 5.0, it has been done many times, look up Terra-Pistiris he is building a Euro 5.0 hybrid right now..
https://rennlist.com/forums/search.php?searchid=2170759

5. In 83 the US got the S which had better brakes, then in 85 the manual trans got better synchros, and 86.5 got the S4 stuff. From 78-81 (US SPEC) you can use adapters on the spindles and bolt on S4 or better calipers.

6. Not stock completely custom, not really a desirable way to go since the exhaust runs to one side since the other side is occupied by the fuel tank. Fuel leak on HOT exhaust pipe = KABOOM.

Since you want the CIS system I would look for 80-83 Euro S spec cars, like the one I had. Its a 4.7, with better flowing intake, larger valves, bigger throttle body, higher compression, most of all MORE POWER <cue Tim Allen grunt> stock form 300hp/263tq.
Now how to tell a Euro S from a regular Euro from a US Spec, I wont get into that here, that is a topic covered many times over in this forum. If you find a prospective car and you are not sure, you can PM me or just post it here and we will dissect it for you.
Basically look for the engine code!! M28-11 for 5spd and M28-12 for autos

82-T/A

Thanks guys, this is some REALLY great information...

Just a few more questions in light of what you guys have recently told me:

1 - Just HOW difficult are the CIS parts to find? Is the problem primarily with the custom parts? Are larger injectors and other generic parts still fairly easy to get?

2 - I JUST caught wind of some information on the 928 that really made me happy. Is it true that the 4.5 motor is a NON-Interference motor? I hate timing belts, and if I'm going to learn to change the one on the Porsche, I want the security of knowing that if I screw up, it won't destroy my valves. Are any of the other motors non-interference? Is the 4.7 an NI? How about the early 5.0s?

3 - Are all or most of the "S" upgrades for the Euro Spec cars interchangeable with the non Euro-Spec?

4 - What years exactly did they make CIS? I know about 78-79, but you guys are saying that the "Euro" version of the 80-83 models are also CIS? Would you guys mind confirming for me exactly what model years came with CIS?



Thanks!!!

karl ruiter

The injections systems are pretty simiilar. I have acually used a volvo WUR on a 928. I have not seen any problem with parts, but then I am just getting them off ebay. You can get a complete spare system for something like $100. The cars you are looking for are something like '78 to '81 US (I don't think they made the transition very cleanly, so in the first few year of the 80s I think there are a mix of cars) and '78 to '83 euro). The most important upgrade in the S package is the improved brakes, but even though they are a little bit better they are still not that loved and many people want to upgrade to S4 brakes. Thus you can buy the whole S brake and spindle package for around $100.

Airflite40

1 - No idea I had stock injectors.

2 - The 4.5 are for sure non interference. I have read in the past that US & Euro 4.7 are non-interference too, but dont remember anything definite. 4.5's are non FOR SURE. I guess it depends on the condition of the engine for the 4.7's since I have seen 4.7's for sale with bent valves.

3 - You can swap any CIS engine into any CIS car, Brad (checkmate1996) swapped a Euro S plant into his 79.

4 - Here is the Breakdown:
77-79 US - CIS
77-82 EURO - CIS
80-83 EURO S - CIS

80-84 US - L-Jet
85+ US - LH-Jet
84+ EURO - LH-Jet

If you get a 78-79 it would be a little silly to upgrade to S brakes since S4 are simply bolt ons...

Dennis Wilson

The 78-79 CIS did not have an O2 sensor so the system is a little simpler than the later CIS. The air/fuel adjustment is the same as all other CIS in that a 3mm allen is used to make adjustments. The down side of that is your adjustments need to be acccurate since there is no other system to compensate (no ECU or frequency valve). The up side of the CIS is that it is normally rock solid if not allowed to become plugged. Also, the 78 and 79 cams have a longer duration and higher lift to effectively use the CIS.

Dennis

F451

This is great information, you guys are a great resource. Ok, enough a** kissing.

I'm trying VERY hard NOT to buy a local '79 US spec 5 sp. Its been for sale for months now, and the price is steadily dropping, and now has the hard to resist - must sell, make offer - note. From the ad, its looks to be in excellent shape.

I've been wondering about the injection setup of this year vs other yrs and models. Also the performance upgrade potential for the car as a whole.

I really need to stop looking at for sale ads and persusing threads like this. My wife is going to freak if I so much as mention buying another 928.

Anyway, keep the great info coming. -Ed

Airflite40

linky?

F451

Hmmm, you wouldn't snap this up from under me would you?

I'm planning on going to take a look at it, but don't want to get into a bidding war with someone is determined to purchase it.

http://seattle.craigslist.org/sno/car/490552217.html

docmirror

Yummmm, phone dials. I wouldn't look for CIS as a beneficial thing, although the L jet and certainly the LH has it's faults too. I like the green. Bonus, it's a stick. Offer $3500 see what happens. These cars just don't move well, obviously.

I've had trouble getting stuff for my CIS, and it's a dying breed, so I would look for the newest you can find unless you're stuck on an OB. Enjoy!

Airflite40

no I'm not, I'm looking for a track car candidate, that one is too nice, and yah what doc said offer $3500...

largecar379

the CIS stuff is easily purchased, the exception being the Euro 4.7L "S" model engine parts. the later L-Jet Euro (16v) parts do appear from time to time, but not as often as the earlier CIS Euro parts (a friend of mine just found a complete Euro L-Jet set up in Europe for $300).

you can (I have--injectors) use some other CIS parts from MB, Volvo, etc., in the Porsche units.

Upside is you can make hp with CIS and not involve electronics.

Downside is you must keep it clean, and if the system goes south, it's pricey to fix.

---Russ

largecar379

Todd,

answers to your questions:

1. Volvo system is basically the same, but with fewer cylinders

2. pressure adjustment can be made using an adjustable pressure regulator and shimming the pressure relief valve (in the fuel distributor)

3. US spec performance (4.5L CIS/ according to my Dad, who just spent big $$$ to get his CIS working up to spec), is really something to behold, meaning that he could not believe that this little motor has so much power---his perspective. Euro spec is the way to go if you have a choice---more HP/torque, less vehicle weight, lower rear gearing.

4. all 928 short blocks will interchange with the earlier cars (yes CIS will "fit" onto the 5.0L), but if you use a 5.0L or 5.4L engine with 16V heads--you will need to flycut notches in the pistons for 16V. Be aware that later (87 and newer) will have a reduced compression ratio, below 8.5:1, when using 16V heads.

5. Suspensions were relatively unchanged--exception is steel ball joints and bigger brakes on 86.5 and newer. the suspension/brake upgrade seen on 86.5 OB, S4 models, and newer is a direct swap to OB (I did this on my '80 Euro). transmissions were better with the 4 speed slushbox or the Euro spec 5-speed.

6. the junkyard car you describe would have been a customized set up--I know of no split exhaust outlets (rear) offered on 928. *there's a gas tank to deal with on the right*

There are other things to consider, but hopefully this will help your decision.

This is by no means complete, and others should feel free to chime in on their opinions and more knowledge than I have......

--Russ