Old Mercedes distributor info request

[jonsey]

Would any one on here now if this distributor runs as a stand-alone unit, or is it controlled via an ecu? It’s off a W123 (I don’t even know what that means). My brother is looking for a distributor to run with carbs on a Mercedes 2.3 16v Cosworth engine. He just wants something that is plug and play as he doesn’t want the complications of the standard ecu driven distributor.

Thanks

[madmog]

According to the part number that's a distributor for the Mercedes 4 cylinder 2.3 M102 engine . I can see it has a vacuum line but can't see if it is running points or not. If it has a set of points it doesn't need a module, if it's some contactless setup it does need a module.

But the ignition curve may be different between the sohc M102 and the Cosworth headed variant.

Here's a link to a cheap 2nd hand one. The supplier, 3 pointed parts will probably be able to advise as to suitability. No connection to me.

www.ebay.co.uk/itm/MERCEDES-W124-IGNITION-DISTRIBUTOR-0031583101/312601433454?epid=1213889994

[tofufi]

Looking at the one in the OPs post, it looks very similar to the one fitted to a friend's 500SEL (except the wrong number of cylinders, obviously). It is not a points distributor.

The 500SEL has the same green lead/wiring plug, and has an ignition module. Something like this: www.ebay.co.uk/itm/292228788825

From memory, that ignition module only has 4 connections to it - +ve, -ve, a wire to the coil, and one other one I don't recall what it does. The green lead goes from it to the distributor, with a plug similar to a radio aerial, and nothing else.

The 500SEL has K-Jet and no computer controlling the fuelling, so the ignition should be a standalone setup.

I think it'd be easy enough to make it run as a standalone distributor for carbs with the correct ignition pack. Certainly worth looking into for the improved reliability over points/condensor IMO.

[Woofwoof]

Jan 7, 2020 14:30:53 GMT jonsey said:

Would any one on here now if this distributor runs as a stand-alone unit, or is it controlled via an ecu? It’s off a W123 (I don’t even know what that means). My brother is looking for a distributor to run with carbs on a Mercedes 2.3 16v Cosworth engine. He just wants something that is plug and play as he doesn’t want the complications of the standard ecu driven distributor.

Thanks

I can't really comment  on that particular distributor but you can bet you're bottom dollar it's not suitable for a high reving, twin cam, big valve M102 . i.e the 2.3-16. As a side note, he'd be 100% better off saving up and fitting a standalone injection/timing system (even better with throttle bodies) , carbs and a mech distributor are not really ideal for an engine designed to run with fuel injection.

[jonsey]

Thanks everyone. I have been messaging the ebay seller mentioned and it looks like it will get the engine running. The module he says goes with it does have a built in rev limiter of 6200rpm which is a bit of a bummer but maybe there is a similar one without the limiter

[carat 3.6]

Jan 12, 2020 19:15:13 GMT jonsey said:

Thanks everyone. I have been messaging the ebay seller mentioned and it looks like it will get the engine running. The module he says goes with it does have a built in rev limiter of 6200rpm which is a bit of a bummer but maybe there is a similar one without the limiter

That's no good for what you want to do. Any reason you cant use the original setup from the 16v?

[jonsey]

The original distributor is empty, other than a rotor arm. The whole ignition is run from an ecu that my brother does not want to fit. When it comes to electrics a 13A plug is pushing his capabilities. With it being a rally car you want to have readily available spares. I’ve tried to convince him to use Nodiz or similar but have not succeeded yet

[Woofwoof]

Nodix is £250, that incorrect distributor is £190...need I say more?

[carat 3.6]

Jan 12, 2020 22:07:44 GMT jonsey said:

The original distributor is empty, other than a rotor arm. The whole ignition is run from an ecu that my brother does not want to fit. When it comes to electrics a 13A plug is pushing his capabilities. With it being a rally car you want to have readily available spares. I’ve tried to convince him to use Nodiz or similar but have not succeeded yet

Unfortunately you've only got two options, as even if you get it to fire up on an old m102 dizzy the characteristics will be way wrong for the 16v.

The original ignition system doesn't use the main ecu, it is all done via the ignition module and it's self contained circuits. The wiring for this is actually fairly simple, and spares are easy to get. This setup has been used many times when the engine is running bike carbs.

The better option as Jhon pointed out is to use an aftermarket ignition setup, which can be fine tuned to suit your engine.

[ChasR]

FWIW, a friend of mine where his car had a similar thing done is now onto engine rebuild no 2 on his car.

For the record, his car was a Nissan DR30 Skyline RS. It went from EFI to carbs. In short, on a set of Dellortos, it overfuelled and killed his engine from bore glazing, and that was despite having the car setup from a well-known East Midlands tuning outfit.

For that reason alone, I'd go EFI with the stock dizzy to run that.

[welshpug]

being a rally car the reliability of a DTA S40 on a set of bodies is hard to beat, fit, get it mapped, forget about it.


good enough for £30k+ Millington engines.


on top of that, get it mapped by someone that knows their stuff (my go to is sandy brown in cornwall) it'll make more power and torque than carbs, and also use less fuel, run cleaner and last longer between rebuilds.

[jonsey]

Thanks everyone for their input. He has ordered H&H distributor with the advanced curve modified for the carbs. It can be sent back and adjusted if further mods are made.

[indyz12]

I'm late to the party! Havent logged in for ages.
That dizzy cap pictured is standard on the older 4 cylinder mercs. The green cable is actually the crank angle sensor for the ezl module (ignition module)