123 ignition to replace 051 distributor

[bracurrie]

I apologize if this has already been discussed, but I was unable to get search results specific to my question.
I am replacing the stock throttle body with one from a 1969 M130.980 engine so that I may use a 123 ignition distributor w/ TUNE to emulate the mechanical advance curve and vacuum retard/advance characteristics of the 0 213 116 051 distributor.
I was curious to know if anyone else had done this and what their experience was like.
Specifically I am looking for the MAPs that others may have loaded that utilize 051 style vacuum and if it is a good idea to use dead cold starting inputs to make starts easier.
Thanks
Brad

[thelews]

I just replaced mine (same stock dist as yours) with the merc 6-r-v.  Works on recommended curve 8 to factory specs advance and retard with vacuum.

[Pawel66]

There is a lot about it on the forum, e.g.:
https://www.sl113.org/forums/index.php?topic=23210.msg214532#msg214532

https://www.sl113.org/forums/index.php?topic=25879.msg185440#msg185440

If you use search function and search words like "map curve", "051 curve" etc. I am sure you will find a lot of material to study.

[Tyler S]

Brad, these are the curves I use. I have experimented a bunch. Though I have a 250sl the curves on the earlier 280s were the same with the 051 distributer. Having the mechancal advance set at 8 degrees @ 500 rpm does aid in starting.

[dirkbalter]

Brad,
I have the same car as your and did the same. I bought the Bluetooth 123 and love is. No comparison (in my case) to an actual 051 dizzy.
My programmed  curve is supposed to mimic the 051 and works great.
However, I will try Tyler's modification to see what is does.
 

[thelews]

No comparison (in my case) to an actual 051 dizzy.

In that case, you had issues with your 051.  The difference between a properly set up and functional 051 and the 123 at the programmed curve is close to imperceptible.  Being mechanical, the 051 will wear and have issues over time and miles.  Being electronic, the 123 will fail completely unexpectedly, if it happens.

I made the switch to preserve my 051 and not have to mess with points in the future and have timing change as the points wear.

[stickandrudderman]

I don't understand why people feel the need to swap throttle bodies from retard to advance.
The net result is always the same: 38 degrees at 3000 RPM with everything connected.

[Benz Dr.]

I don't understand why people feel the need to swap throttle bodies from retard to advance.
The net result is always the same: 38 degrees at 3000 RPM with everything connected.

You would normally have to match the distributor type to the throttle body being VA or VR.  With electronic,  apparently that has no effect?

[dirkbalter]

@ John,
I agree with you that there should be no difference between a properly working mechanical distributor and a 123. I have two rebuild 051's that I believe are working as good as they can. The other components however, points particularly, are not manufactured to the quality they used to be. I drive my 108 quiet a bit,5-6K per year. After I installed all new components (051) first, the car ran good for about 3-4K. After that I noticed occasional cut outs at idle and once in a while it would stall at a light. I re-adjusted (points)  and checked everything again and I would be fine for a while. Not thinking that it necessary was the ignition, I went through the fuel system, linkage adjustment…...
Not really understanding what is causing the problem and why it is coming back, I bit the bullet and installed a 123. The car instantly ran better, great consistent idle, starting....Now in the car for 2k and not a single issue. (Fingers crossed.)
That's where I am coming from.

@Stick
I believe the issue is not advance versus retard. Its about the (faulty or broken)elimination of the electronics of the late US 280's with emission control. These have a different trottle body that either needs to be modified or replaced

[stickandrudderman]

@Stick
I believe the issue is not advance versus retard. Its about the (faulty or broken)elimination of the electronics of the late US 280's with emission control. These have a different trottle body that either needs to be modified or replaced

My comments are not aimed at anyone in particular, rather a general observation.
In all my years I've never yet had to overcome the US emmissions installation (I've seen plenty of US import cars but no late ones with this system) but I have fitted hundreds of 123 distributors with great success. Presumably the US spec throttle bodies will have either adv or ret. and that can be managed in the 123 settings.
My point is that some people seem to be under the misguided inpression that fitting an "advance" throttle body will somehow improve performance. It doesn't.

[kampala]

Stick,

The issue with late USA 280's (with vacuum all-the-time at throttle body) and a standard 123 with pre-programmed curves is that the 123 docs suggest to use program "E" with these late USA cars (distributer 062 I think?)  The 123 program "E" expects that all items in the chain are working properly, especially the two-way valve that controls the vacuum between the throttle body and the distributor. 

This is the issue - Since Program E expects the two-valve to turn the vacuum on and off based on rpm and such (since these late USA 280's have vacuum all-the-time from throttle body),  the problem is that many folks want to put the 123 to bypass all the black box control units that manage this two-way valve as its a huge amount of work to get all those electronics to function as they used to. 

By changing the throttle body to an earlier type (one that would be found on a car with a 051 dizzy) where vacuum is cut-off by the throttle body, one can install a standard 123 and use program 8 and in turn bypass the control boxes and two-way valve.  One can also modify the throttle body - if you know what you are doing.

Now, due to the somewhat new fully programmable 123 units, one can probably make a curve to work with vacuum all the time - I would guess - and leave the original throttle body.  Too much computing for me.

[dirkbalter]

Oz,
Nicely said. We should add that to the tech manual for future reference. The subject comes up frequently.

[stickandrudderman]

Thanks Kampala, that's clearly an issue I wasn't aware of.

[Tyler S]

Oz, You are correct in that there are 2 different 123 Ignition units being described in this thread. The latter is a fully programmable unit that can have a map written any way you choose. I did an experiment about a year ago in which I connected my 123-Tune programmable bluetooth distributor to manifold vacuum behind the throttle plate. Just like on the later cars with emissions switching. There just so happens to be a plugged off grub screw. I was able to create a map that worked well with this setup. This seems to be a way to go for the later cars without changing the throttle body. The key here is you need the latter Bluetooth programmable 123 distributor. The earlier units with the selector switch set to curve 8 wont work correctly on the later cars with disabled switchgear.

[kampala]

Tyler

One day in the future, if COVID really goes away, I would like your help to try that fully programmable unit on my 280 that is currently running the standard 123 with a modified throttle body.  I can just plug the vac port I drilled and unblock the original port.  If that works well I can move my standard 123 to the 250 as that car is running a 051 with pertronix.  Hey it’s only a 100 mile drive south for me —- I’ll buy lunch 

and dinner if we don’t get done.

And of course I would bring a tune 123. 

[dirkbalter]

And I buy drinks if you guys let me join.

[mrfatboy]

As soon as Covid is over we are planning our Pagodas & Beer event. Perfect time to do it👍👍

[Harry]

Where are these distributors sold in the USA?  I am in Tennessee.

Thanks,
Harry

[thelews]

Where are these distributors sold in the USA?  I am in Tennessee.

Thanks,
Harry

www.123ignitionusa.com

[bracurrie]

I know this is old, but I wanted to thank everybody for there reply posts to this thread.
I did want to add that an additional benefit of the 123 programmable is that once I set mine for as much advance as my engine will take and not ping on 93 ethanol free gas I want to be able to back off the timing in case I am traveling and can't get high octane gas.

[Tyler S]

Brad,
How did those curve maps work out for you?

[Nicolas Aristodemou]

I have been using the 123 Bluetooth for the past 6 months on a 1970 280SL with working emissions controls. (Actually it wouldn’t have mattered if they didn’t work). I have kept the original throttle body and programmed the 123 unit to ignore vacuum inputs completely, in other work the vacuum curve is programmed to give 0 advance to any vacuum input it gets from the throttle body.

I use only the centrifugal curve - in name only since the 123 is fully electronic- to start from 8 deg BTDC at 500 rpm and to advance gradually to 38 deg at 3500 rpm (15 deg at 1500, 25 dec at 2000, 30 deg at 2500, 35 deg at 3000)

I have used the car for almost 6 months now it runs perfectly and has a lot of pulling power and no pinking. I have done over 3000km with his setup.

I know people would probably say that vacuum advance gives a more rapid response by advancing timing at low throttle settings but I haven’t noticed any problems myself. The car pulls very well. Besides emission control cars are programmed to remove any vacuum at over 2400rpm  by the activation of the electric vacuum valve.

[MarkCan]

I just replaced mine (same stock dist as yours) with the merc 6-r-v.  Works on recommended curve 8 to factory specs advance and retard with vacuum.

Enjoy some pictures at this link:
http://www.flickr.com/photos/8292359@N06/sets/72157603240571101/show/
I did enjoy looking at your car. My 230 project was originally red as well. I was thinking white and now I’m not sure.🤷‍♂️