S2 engine into 1983 car

[tom_babbs]

Ok so having stripped the engine from my car i have commited to buy a 3l engine, ancilleries, clutch and ecu with new cam and balance belts from an s2.
Hopefully it will be a relatively easy job and i will get my car back on the road in the next month or so, with a bit more grunt!
So are there any pitfalls i should watch out for, and pointers for my rebuild?
Thanks in advance Tom

 

[Jonny944CS]

Sounds like an excellent project Tom.

For an '83 car, a few things come to mind off the top of my head:
- Proximity of the brake master cylinder to the inlet manifold (I believe '86-on cars had a different firewall, moving the booster/master cylinder up and to the right)
- I think the early multipin engine bay connector is different to the S2 (should just be a case of studying the wiring diagrams)
- Rev counter wiring (may also need some thought)
- The fuel lines come from the driver's side of the engine bay on an S2/ late models
- Provision for the larger radiator, oil cooler and airbox

I would be very interested to hear how you get on as I've been considering something similar myself. Good luck and please post lots of info and pictures []

 

[Mike_Pollock]

It is a bigger job than it may appear!

As Jonny says and you will need ALL the late cars engine electronics and wiring - lots of the sensors are different - several are even different on the pre and post 85 2.5 cars.

Good luck with it and I'll help if I can.

 

[tom_babbs]

Hey all thanks for the encouragement.
I didnt realize that i would need to replace the radiator, is it bigger on the later cars, does it still fit i the same space?
Where does the oil cooler mount on the later cars?
Will i need to fit the bigger air box or can i use the existing?
I have a friend who is an auto electrician i think i may try and recruit him (hopefully) for some help with the sparky bits!

Thank you Tom

 

[GlennS]

The S2's airbox normally lives in front of the radiator under the (removable) badge panel. Some other notable differences from an early car are the battery location (in the boot) and the location of the main fusebox (where the battery lives on early cars) which may cause you some wiring loom fun.

 

[tom_babbs]

Ok i have paid a deposit so there is no going back!

I am getting the loom with the engine as well so it is just a case of connecting the ecu into the rest of the car, could still be tricky!

Spoke to my mechanic friend who is willing to give me a bit of a hand but he is having all sorts of problems with his rally car so he is very busy at the moment.

I will look at the air intake when it arrives, i may stick a cone type ram intake on it if i cannot get my air box to work.

I will connect up to my existing radiator and monitor the temperature carefully and maybe upgrade later.

I will play with the tacho when i know what i have to go with.

Brake master cylinder could be a bit tricky i will get the engine in place and then see what room i have.

Oil cooler i will find somewhere to put hopefully where it will get a bit of a breeze!

Fuel lines i will play with once engine is in-situ.

Cheers i will keep you updated as it progresses, just got to wait for the engine now, which will propably take a week or two as i live on a bloody rock in the Irish Sea!

Tom

 

[Jonny944CS]

Where does the oil cooler mount on the later cars?

Here is the factory install in a 968:

This pic shows a retro-fit example in an '89 lux:

See below for some light reading, while you wait for SS 3litre to dock [] (968 engines, but similar in many respects):

www.944s3.com

http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/256169-i-swapped-968-into-924s-2.html

Engine loom connector pin-outs for later cars

 

[tom_babbs]

Thanks for the pictures and the links, very handy, looking forward to starting the fit now.

 

[peanut]

you'll need the S2 rad I should have thought. With so much more power in the S2 the extra heat needs to get dissipated.
The fact that the S2 have twin 2x speed fans should tell you something.[]

The other biggy is the ECU and the additional sensors, plus the ignition amplifier, hall sensor ,different crank speed sensor S2 has 1x, early cars have 2x I believe?
The early fuel pump might not be up to it and you will definitely have to increase the fuel pressure for the S2 injectors to work properly.

Crikey its not a job I'd take on tbh . []
I'd be tempted to sell my 83 for £1k or whatever I could get and buy a cheap S2 complete for £1k to £1.5k and do that up. That way I'd get to spend more time driving it than working on it lol[]

 

[Jonny944CS]

you'll need the S2 rad I should have thought. With so much more power in the S2 the extra heat needs to get dissipated.
The fact that the S2 have twin 2x speed fans should tell you something.

I believe (though I've not seen any parts side-by-side to confirm) that the S2 radiator is taller and slightly thicker. Can anyone confirm this?

To install it would probably require the S2 cross-member, that supports the bottom of the radiator, to be fitted in place of the early Lux L-Shaped supports.

The other biggy is the ECU and the additional sensors, plus the ignition amplifier, hall sensor ,different crank speed sensor S2 has 1x, early cars have 2x I believe?
The early fuel pump might not be up to it and you will definitely have to increase the fuel pressure for the S2 injectors to work properly.

I guess the key is to purchase a complete engine assembly, that is to say inclusive of the ECU, loom, sensors, 60-2 flywheel trigger, 3bar fuel pressure regulator, injectors etc. etc. etc. (which Tom has done if I understand his posts correctly).

The interesting bit is then making sure that the engine loom connects to the chassis loom correctly in order to provide:
- power inputs to the DME
- signal/power outputs to the instrumentation
Having done this correctly, the engine should look after itself, shouldn't it?

Good point about the fuel pump. Does it have a larger capacity than the early unit?

 

[bertelli_1]

ORIGINAL: Jonny944CS

you'll need the S2 rad I should have thought. With so much more power in the S2 the extra heat needs to get dissipated.
The fact that the S2 have twin 2x speed fans should tell you something.

I believe (though I've not seen any parts side-by-side to confirm) that the S2 radiator is taller and slightly thicker. Can anyone confirm this?

To install it would probably require the S2 cross-member, that supports the bottom of the radiator, to be fitted in place of the early Lux L-Shaped supports.

The other biggy is the ECU and the additional sensors, plus the ignition amplifier, hall sensor ,different crank speed sensor S2 has 1x, early cars have 2x I believe?
The early fuel pump might not be up to it and you will definitely have to increase the fuel pressure for the S2 injectors to work properly.

I guess the key is to purchase a complete engine assembly, that is to say inclusive of the ECU, loom, sensors, 60-2 flywheel trigger, 3bar fuel pressure regulator, injectors etc. etc. etc. (which Tom has done if I understand his posts correctly).

The interesting bit is then making sure that the engine loom connects to the chassis loom correctly in order to provide:
- power inputs to the DME
- signal/power outputs to the instrumentation
Having done this correctly, the engine should look after itself, shouldn't it?

Good point about the fuel pump. Does it have a larger capacity than the early unit?

Will definitely need the loom as it is quite different (seperate injector resistors, ign amplifier & ecu plug, plus others...).

I think the only difference with the servo is the mounting bracket, which moves it further forwards.

The rad is indeed deeper on the s2 so some metalwork will be required to get it to fit.

The heater control is a very different setup requiring a manual valve & a longer bowden cable.

Its been a while since I did the swap to a 924s but physically fitting the engine is easy, all the ancilliary stuff which causes the headscratching. Oh, the revcounter wont work, you'll need an aftermarket one.

 

[tom_babbs]

I have indeed bought the wiring loom and all of the ancileries to go with the new engine so as stated the intresting bit will be connecting the ecu into the car after that it will all be s2 componentry.

With the radiator i will stick to the one for the car and if it runs hot i will fabricate something to fit the bigger rad.

An after market tacho does not appeal, but if it needs to be i shall install that after the rest of the engine is sorted.

The brake servo maybe an issue but as stated before i will address that when the engine is in situ, one of the websites that i have read were an american had undergone a similar process stated that the engine did, just fit, although it didn't leave much room around the servo.

I had not even considered the fuel pump, i suppose the 29 year old one on the car is propably not at its peak performance anyhow.

The heater cable was jammed on the car anyway so a new cable, longer cable would propably be a good idea.

As for why do this with the existing car is i intend to hillclimb the car so the older it is the sooner it will be eligible for historic classes and the engine that was in the car is toast so i would be lucky to get much for the car as it is! Plus an older lighter car with no power steering etc and more grunt appeals to me!

Cheers Tom

 

[peanut]

ORIGINAL: tom_babbs

As for why do this with the existing car is i intend to hillclimb the car so the older it is the sooner it will be eligible for historic classes

Cheers Tom

well I wish you luck, keep us informed of progress on this challenging project .Would the car be eligable for classic races with a non standard engine ?

 

[JamesO]

With the early car being lighter han the S2 and less effort to move around I would have thought you could get away with a smaller rad. I ran a 3l S2/968 engine in a late Lux with the single fan and it never ever ran hot, even on repeated back to back 'Ring laps and heavy London traffic.

There is actually a handy mounting point for an oil cooler behind the frount valance but you will need some way to duct air to it. My current engine has an S2 oil cooler, which I have mounted in front of the rad with a couple of home made brackets.

 

[Peter Empson]

ORIGINAL: JamesO

I ran a 3l S2/968 engine in a late Lux with the single fan

Same here, and that was with the original radiator (IIRC) and no problems with water temps (oil temps were a different matter []).

 

[944 man]

A build thread would be greatly appreciated.

 

[Jonny944CS]

ORIGINAL: Peter Empson

Same here, and that was with the original radiator (IIRC) and no problems with water temps (oil temps were a different matter []).

Was that with the oil cooler and pre or post supercharger Peter?

 

[bert gear]

you will need the S2 ECU, rad should be fine 2 fan cars were only for cars with AC

 

[Peter Empson]

ORIGINAL: Jonny944CS

Was that with the oil cooler and pre or post supercharger Peter?

That was before the supercharger, with the S2 oil cooler, but getting enough air flow to it seemed to be the problem, even with a hole cut in the standard bumper it didn't seem to flow very well. I'm still running the same setup (but with a lot more air flow thanks to the new bumper) but it's rather marginal as you'd imagine, a bigger (and better located) oil cooler will be fitted at the next oil change.

 

[Jonny944CS]

Very interesting, thanks for the feedback.

Baz's comments (here) on oil squirters are also 'food for thought'

'You can buy M96 oil squirters and drill reducing sized holes from where the shell fits upwards so they cannot fall out. We are experimenting with this in a 997 to improve cylinder lubrication but expected a reduction of oil pressure on hot tick over. Instead it went up because oil also cools the engine, lowers oil temperature overall and therefore improves viscosity - so good all round.

The 3 litre 944 mk 2 turbo engine we were building will similarly be fitted with squirters (it has a modified 2.5 block) it seems beneficial all round.'