advance curves 123 Ignition (16 preset version)s 123 Ignition (16 preset version)

[EJ74]

hey to all 02 friends out there!

 

i got a questions - as I can't find any information on that over here in Europe... or I may enter the wrong search strings in google

thinking of buying the 16 preset version of the 123 ignition and interested in what advance curves are offered there.

it starts at 3° at the static setting, and ends at 30° - but would like to know how that changes over the RPM curve.

 

and - if any of you already did the dynamic timing setting - what degrees did you put the 123 in advance at ca 1000rpm

thanks in advance for your input 

greetings from Austria

Ernst

 

 

[zinz]

For all the different curves on the switchable model, scroll to page 25 on the 123Ignition manual here: https://www.123ignitionshop.com/manuals/SWITCH4.pdf

 

You would likely need to cross-reference that information with the actual curve data found in the blue BMW Shop Manual or search FAQ

 

Here's a thread with some curves displayed: 

 

If you are using the switchable 123Ignition distributor, you would install it as a normal dizzy, select the pre-set you desire, and time the ignition (with a timing light) according to the manual... these timing points are given as a range of several degrees because some engines run better with a little more, or a little less advance.

 

Example - timing for a standard 2002 is stated as  21-25 degrees at 1000rpm

 

Here's the Haynes Manual pages for ignition timing  Haynes ignition specs.pdf

 

Hope this helps,

 

Ed

 

Edited February 22, 2017 by zinz

[EJ74]

Hi Ed

 

thanks for that input - I was just wondering if the 123 is doing the adjusting the timing on its own. I know that from an ignition in one of my motorbikes. there I time to a given degree advance based on the manual and it does up to 10° from there based on rpm.

 

so - if I install the 123 and put it on the static setting (green LED on at static TDC) i would still need to adjust to the 21-25° advance at 1000rpm

just want to be sure the 123 is not adding too much advance then.

 

thanks

ernst

 

[zinz]

I run a Tune Model and use a timing light to confirm the curve is where I want it. From my experience, the 123 acts like a regular dizzy in that, if I turn the body of the 123 by 5 degrees, it adds 5 degrees to the entire curve. 

 

Ed 

 

['76mintgrün'02]

I run a "regular distributor", so I do not know much about the 123... but, I do believe the following information applies to both.

 

Since the crankshaft rotates TWICE for every camshaft rotation (eg a 2 stroke cycle), then the distributor also rotates ONCE for every TWO times that the crank turns.  Distributor Speed = Cam Speed = 1/2 Crank Speed.

 

Since the flywheel is mounted to the end of the crankshaft, they turn together.  Therefore, since the crank turns twice for each distributor turn, if you turn the distributor by 5 degrees, then this will alter the crank timing by 10 degrees.

Tom

<<Edit>>

I swiped the last two paragraphs from this site

http://1931chevrolet.com/specs7d.htm 

Edited February 24, 2017 by '76Mintgrun'02

[TobyB]

For what it's worth, M10's seem to run best with 36- 40 degrees of advance, all in, over 4000 rpm.

That's a pretty safe number- I've never seen any evidence of detonation with that final timing point.

 

So if you wanted to safely experiment, you could time the 123 to that, and then see what the different curves

do for you at idle and part- throttle.

 

Some form of load sensing is very useful, be it vacuum, throttle position, plug gap resistance, whatever...

 

t