RonnyÅ

Hi folks. Is there anyone here who have done this conversion?


I'm wondering about if it's possible to use the complete ecu and sensors from the 8v on the 16v to have it working. What kind of problmes would i run into? Is the flywheel and the clutch the same (or fit)?

Is the trigger system the same or do i have to change something there?

I have the upper exhaust header for the s2, but would that one fit the old downpipe?

What can be done with the trotthle wire?

-Ronny

TurboAngel

Hi. Yes I've done it (89' S2 engine into 86' 944).

I used the S2 engine wiring loom and also an S2 engine compartment wiring loom.

The S2 engine harness has 2 knock sensors. These sensors are controlled via the ECU. The S2 also has a cam sensor.

The flywheel has a 60-1 timing setup (teeth cast into the flywheel). Only 1 sensor is used.

Porsche for some reason rotated the exhaust header flanges so your existing 8v downpipe would need some attention to make it work.

What year is your 8v?

RonnyÅ

My 8v is an 1982 modell. I dont have the ecu for the s2, so if possible, easiest for me would be to use the old computer with triggering system from the old engine.

I guess that the ecu run on map based on VE and not on MS opening of the injectors, and since the bore of the 3.0 is bigger, the timing wouldnt be to far off. Or would it? And i can also run the car on 99 octane gas.

Dimi 944

I will be doing the same conversion (89' S2 engine into 86' 944) in a month or so. I have pretty much everything needed. I might need some assistance with the wiring though. I am almost positive that a S2 DME is needed for the conversion. The wiring is different and there are additional components needed for the ignition if the motor is from '89-'90 S2. The throttle cable has to be from the same year S2 well.

RonnyÅ

Do you really HAVE TO use the s2 ecu? I mean.. both engines are 4 sylinder with low imp injectors witch are regulated in "batch fire" and the fireing order is 1-3-4-2.

I do know about the throttle and that it would need som ajustment.

If the mixture is too far of, I can ajust it with a wideband O2 sensor and a ajustable fuel pressure regulator.

TurboAngel

Obviously the S2 has a longer stroke - even the 2.5 16v ECU doesn't work in the 3ltr because of this fact.

The 16v engines also have an external injector ballast pack , again driven via the ecu.

My 92' S2 has brown tops (high imp. injectors) I think this was a change made from 90' onwards so probably irrelevant.

murrayg

I too will watch this space closely. I'm about to buy a junker S2 for the drive train to swap into my 84 944. This should be easy for me since I will have the entire car. Any good info or sites is appreciated.

Where is everyone doing this from??

Gord.

Arominus

You need the ECU, they are out there, you need to get one. Keep it simple and you will actually be able to complete the swap. You need every bit of wiring from the S2 engine compartment, the ECU, S2 engine w/ sensors, and the S2 flywheel/clutch.

RonnyÅ

Dont i need 2 ecu's on the engine (and i miss the air flow meter)? And how could i make the rev counter working?
I would like for the car to be as original as possible with the wireing etc, to save time and work.

I guess the s and s2 uses the injector ballast since the ML 3.1 cant handle low imp injectors? Anyway i intended to use the old loom for now.

Of course i know that this is far from optimal, but i need the car running. And later i anyhow intended to use a stand alone ecu.
If mechanically possible, i was hoping to temporary use the old electronics. And adjust the fuel a bit with an adjustable fuel regulator.

RonnyÅ

Is it possible to find an original ignition advance table on the 2 engines online?

Grandpa#3

RonnyA, you have been given great advise on what you need for the conversion. A Big "BUT" you fail to listen. Keep your car as is for now and save up the money for a complete change over, ECU, and Wiring Harness's plus the Clutch. Don't do a half a$$ job as you will not be satisfied, nor have a good running engine and will be right back here wanting HELP.

Cheers,
Larry

RonnyÅ

the thing is that my cambelt broke, and all 8 valves and 4 pistons is broken. The old engine is ****ed and i need the car running. I'm not stupid when it comes to engines, and tuning ignition and fuel. I've build several engines from scratch and adjustet stand alone ecu's. And driven maby 3-4 years with Megasquirt on a daily car (from minus 25 celsius to + 30).

This is temporarly because i need the car running, and not to swap for a s2 because that was the idea. It was the engine i got hold of.. thats why.

Apparently no one can tell me if the sensors or triggering system would fit. I guess i would have to find it out myself.
And no one seems to know the original spark advance on eighter of the engines.

Btw. i HAVE both the harness and the clutch. i miss ecu's and air flow meter. And would the rev counter work?

MAGK944

Really, ALL the valves are bent and what is "broken" about the pistons? I only ask because I never heard of such damage from a cambelt failure before.

If you pistons just have contact marks from the valves they are not broken. Many 944's, including me 951, are running with these marks on the pistons. If a piece of valve broke of and damaged the bore then that's another story but it's unlikely that happened, they normally just bend.

Even if all your valves are bent (unlikely) you just need the head rebuild, valves/guides and you are good to go. Save a bunch of time and money and get the car running again which seems to be your priority.

RonnyÅ

All 8 valves is bended. So i would have to change all of them and the valveguides in case they are damaged. All 4 pistons have marks from the valves, witch can create "hot spots". The engine had 283 000 kms on it, so its stupid to only rebuild the head.

I took the engine out yesterday, today i've changed the triggerwheel and most of the electronics. Hopefully I would start tomorrow with putting the s2 in the car, and work out fuel lines, throttle and exhaust. I hope It's possible to turn/twist the flanges on the downpipe by heating them. They don't look welded to the pipes.

RonnyÅ

Also, it looks like someone either have been putting 16v pistons in my old engine, or the 8v pistons uppside down..