123ignition distributor install

[m5bb]

IIRC doesn't the 123 ignition have the ability to store a couple programs?
You could always have one for around town and another for long cruise on the highway.

Yes, many old timers use the advance it till it pings system. It does work and tells you what the max advance can be.
With the higher compression I will be running the advance will be limited because of detonation.

I have a Miller MAF system in my M5 and it actually stores a couple programs and with the flip of a switch you can change it.

I plan on running mine without the vacuum advance. Mostly because it doesn't work well with the Webbers and they don't recommend it.

Great info and thanks for posting.
You're getting me excited(not that way) about my new engine.
Gary

 

[sfdon]

Load- how open you have the throttle.
100% load is Wide Open Throttle [WOT]

 

[jamesw]

Fantastic project - thanks for the report Steve.

Cheers
James

 

[Stevehose]

Yes it can store 2, with a toggle switch you can activate either one. Once I feel comfortable with the whole realm of possibilities I will definitely take advantage of that feature.

IIRC doesn't the 123 ignition have the ability to store a couple programs?
You could always have one for around town and another for long cruise on the highway.

 

[rsporsche]

Since ignition advance is compression dependent....
The m30 model big six varies from the 7:1 early 745i all the way to the 10:1 euro spec dirty engine.
One map doesn't fit all...
If you would like a safe starter ignition timing map for a 9:1 engine let me know.
Keep in mind 91+ octane!

Don,

one of the advantages about not living in california. 93 octane - readily available.

 

[Luis A.]

Steve, thanks for documenting all of this. A great resource for the group.

When and why did you give up on the Zeniths? Am I just delaying the inveatible in trying to perfect my Zeniths?

 

[Stevehose]

I never gave up on the Zeniths and have always liked them. 30 years ago on my first coupe i replaced them for downdraft Webers because that was the thing to do and i didn't like the change. Nowadays i try to convince people to properly rebuild and keep the Zeniths, they are well suited to the e9 imho.

I did the triples for different reasons - to have a challenging project, their reputation for visceral feedback and they look exotic like ones fitted on contemporary Maseratis and Ferraris. And i could always go back.

I think if you're staying stock then keeping the Zeniths is the way to go.

Steve, thanks for documenting all of this. A great resource for the group.



When and why did you give up on the Zeniths? Am I just delaying the inveatible in trying to perfect my Zeniths?

 

[Tierfreund]

I never gave up on the Zeniths and have always liked them. 30 years ago on my first coupe i replaced them for downdraft Webers because that was the thing to do and i didn't like the change. Nowadays i try to convince people to properly rebuild and keep the Zeniths, they are well suited to the e9 imho.

I did the triples for different reasons - to have a challenging project, their reputation for visceral feedback and they look exotic like ones fitted on contemporary Maseratis and Ferraris. And i could always go back.

I think if you're staying stock then keeping the Zeniths is the way to go.

I agree wholheartedly. Bought my E3 with a very nice tripple weber 40s setup on a stock 9:1CR 3 Liter Euro Spec M30. Spent $$$ making it run as nice as possible and it did run very nicely. But my E3 is a daily driver and I wanted automatic chokes, the ability to floor the pedal in fifth and 1200rpm + the Zeniths really intreagued me. They are fabulous little masterpieces of mechanical fuel distribution.
So I went from tripples to freshly overhauled Zeniths.
No regrets. The little I lost in power and aural excitement I won in refinement and practicallity.

The Zeniths really have a bad reputation for the wrong reasons. Anyone capable of getting tripple Webs running well would probably get the Zeniths running fine just as well.
The downdraft Webers on the other hand are a bit of a compromise on the M30 and only worth considering if your Zeniths are really bad and you can´t be bothered...

The 123 looks really neat. I wnated to go that route years ago when I was tired of contact breakers but they we´ren´t really available for the M30 then. So I went Pertronics in my stock dist and am quite happy.

Maybe I´ll give the 123 a go once I´ve converted to L-Jet (my next project, have everything here and overhauled, just currently no time for it (because of the Jag))

So well done, and thanks for documenting, very neat!

 

[Stevehose]

Yes the triples require more user involvement. You have to wait for the engine to warm up before it will hold steady idle and will pop and protest until it is, you better like the smell of gas and be willing to occasionally eyeball the linkages and fuel fittings for anything astray.

That's once they are set up correctly...

The 123 distributor does add some civility to them from being able to dial in the timing they like, especially at idle.

The little I lost in power and aural excitement I won in refinement and practicallity.

 

[deQuincey]

Steve, thanks for documenting all of this. A great resource for the group.

When and why did you give up on the Zeniths? Am I just delaying the inveatible in trying to perfect my Zeniths?

nothing inveatible, keep the zeniths, luis

 

[deQuincey]

Yes the triples require more user involvement. You have to wait for the engine to warm up before it will hold steady idle and will pop and protest until it is, you better like the smell of gas and be willing to occasionally eyeball the linkages and fuel fittings for anything astray.

That's once they are set up correctly...

The 123 distributor does add some civility to them from being able to dial in the timing they like, especially at idle.

hi steve, excellent work that of yours !
will keep this thread stored for the future,...hope i will never need it ;-)

 

[Stevehose]

Update

The vacuum anti-pulse valve arrived so I tested it out with a vacuum gauge and it indeed reduces the pulses, not as much as linking all barrels together but enough that it works with the distributor. I bought this from Dellorto Carbs UK but I think aircooled.net has them also.

So I now run the manifold vacuum off the rear most barrel and capped the other ports, the carbs prefer to not be linked together.

I took it out for a test drive to see how the now single-port manifold vacuum behaves during various driving conditions, especially at load. When I floor it the vacuum under load drops to the 4-0 range so I recurved my dsitributor to have the vacuum advance drop out no later than 5 as a safety buffer. I have the vacuum advance programmed to add 6 degrees at all conditions except load so idle and cruise get advance. This gives the engine a nice smooth idle, especially when cold (I don't need to wait as long for it to hold steady) and some fuel economy (hopefully) at cruise (34 mechanical + 6 vacuum = 40 total advance at cruise). Here is the new curve map:

Since the advance function and this distributor work so well I decided to try dropping an idle jet size to see if I could lean up my idle and cruise AFR's. I went from a 60F17 (with enlarged air bleeds) to a stock 55F17 and it has made a lot of difference. Before the 123 my engine would not accept the smaller jet but with the new advance etc it not only handles it but it has made a big difference. I get a nice lively idle note and the intake noise has gone up a note or 2 in pitch (intake noise, I have determined, is also an indicator of lean or rich running conditions, rich will be more muffled and lean will be more hollow sounding). Now my idle AFR is up a half point or so and the rest of the range is up a point with no popping or other ill effects like before.

For those of you with triples, it is clear that these carbs like a lot of advance not only at idle but early on in the rev range. So if you are runing a stock distributor you are missing out on a lot of potential so I suggest to get it recurved or buy one of these. I am now just realizing this in my thick head after reading about it on many weber sites and from 61Porsche here previously.

This will be my final curve to fool with before some dyno time at some point. I am not sure that I will need to program a second curve to switch between, I don't track this car so I am not certain I will use this feature.

It's like a new engine now.

 

[deQuincey]

interesting, i just ordered a vaccuum stabiliser valve, thanks

 

[Stevehose]

FYI the arrow on the side of it points to the carburetor (source of vacuum). Also you may not need it because your zenith will be receiving 3 cylinders of vacuum each which will already be smoother than one barrel of a weber side draft.

interesting, i just ordered a vaccuum stabiliser valve, thanks

 

[deQuincey]

FYI the arrow on the side of it points to the carburetor (source of vacuum). Also you may not need it because your zenith will be receiving 3 cylinders of vacuum each which will already be smoother than one barrel of a weber side draft.

i had never thought of it, but indeed my vaccum is not smooth
when i synchrotested my carbs with vaccum gauges it was needed to strangle the hoses to get a steady reading, this clearly means that vaccum can be improved
so your great find might be of some use
thanks

 

[Stevehose]

Ok so I wasn't done messing around with the timing, it's easy to change scenarios so I did some seat of the pants testing today and it feels like it responds better to a little less timing at full load (with accel jets blasting fuel etc) and more vacuum advance under light load. I upped the vacuum advance to 10 and dropped the mechanical advance curve across the board, maxing out at 32. I eased the slope on which vacuum advance drops out as load increases. Idle timing is the same, just different addition. Cruise all in is now 42 and the engine seems to like. It will be interesting to see what the dyno says. It's really cool to recurve the distributor on the side of the road in a minute or 2 then test it out right away. It's also good practice so I don't waste dyno time.

I also found a use for one of the hex wrenches in the tool kit-the middle size fits the USB port cover screw.

 

[m5bb]

Following closely Steve,
Great info and sure will help me in a couple weeks.

Thanks,
Gary

 

[tmason]

Nice reporting Steve and your cars is amazing! Thanks again for the tour around New Orleans! Priceless...

 

[Nicad]

I am late to seeing this thread Steve(have been busy studying the permutations of Subaru parts interchangeability) Congratulations on doing this valuable R&D. I have a feeling you are enjoying the process.
Just wondering if a knock sensor is something that either integrates with the 123 system or you have thought about?

 

[Stevehose]

No knock sensor integration. Just my ears and fat ass to go by! Under load it's max 32 which is within the stock amount anyway.

I am late to seeing this thread Steve(have been busy studying the permutations of Subaru parts interchangeability) Congratulations on doing this valuable R&D. I have a feeling you are enjoying the process.
Just wondering if a knock sensor is something that either integrates with the 123 system or you have thought about?