123 Ignition on 2L alfetta

[Fetta GTV]

Hi all

Is anyone else running the 123 ignition (replacement electronic distributor) on their 2L motor
What static advance should I be running
Mine is running well, idle is good, revs well, but pings under heavy load
I'm running premium unleaded

Cheers
Fetta GTV

[Fetta GTV]

Am i the only one with one of these distributors?
Changed to a different curve and it seems a little better
I think it needs a really good run to clear it out, only done a few Klms since rego

[Rigi]

Nope not the only one, i have currently got one. Which curve are you running to start with?? then we can figure the static advance.

[Fetta GTV]

I'm running the 'E' curve at the moment
Not sure if its the best option
The engine is standard and a little tired
My crank pulley is the double belt type and has 3 marks on it 2 close together and 1 quite a way around from these 2
I removed the air conditioning ages ago that the other belt was for

thanks for the help

[Rigi]

you will notice that many of the curves are actually the same, i've attached an excel spreadsheet showing the curves.

Curve E has a very quick advance, which i would have thought in an engine that is tired this kind of curve would be fine IF you set minimal static advance, like fractionally past the first marker. Though you may still have a problem with it advancing too quick. When is it pinging? when you are steady accelerating or when you jump on the throttle? and how have you setup the timing currently??

The best way to tune it is if you have a timing light, to get someone to hold the revs at 3-4K revs (when the ignition advance is at it's maximum) and align the timing mark to the M (maximum advance, the one by itself) mark.

[Fetta GTV]

I have set the timing to the second mark with a timing light at idle
It it pinging only under heavy load, going up hill in a high gear with a fair bit of accelerator and not changing down
Taking it up through the gears and not loading it up it revs with no pinging

[Rigi]

With that you have WAY WAY too much advance, if you do the maximum advance check you'll find that when the dizzy reaches maximum advance (say 4.5k RPM) it will be past the last mark on the pulley. Alfettas have around 30 degrees maximum advance. With that curve and on the static timing mark you end up with around 40 degrees. So first step I'd simply knock the static timing off a little, try half way between the first 2 marks on the pully. And just go from there if it still pings then maybe back it off a little more or that curve is still too steep and you could try curve A. Every engine is different especially older ones!!! 

Also If this timing changes causes it to idle a little slower, then you may need to bring the idle speed back up a little too.

[Fetta GTV]

Backed it off to half way between the first 2 marks
No more pinging, seems to start much better hot now as well
Thank you for all your help
Feel a whole lot better about the trip to Phillip Island now

Thanks Again

[Rigi]

Glad to help
i'll be going to PI too, Guess i will see you there then!!

[sportiva]

have you guys with 2l engines played with the cam timing, something i cant do with my 2.5 v6  with the nord engine you can retard or advance each camshaft individually so you can play with the valve overlap for different engine performance like more torque OR power the differences are not great but you can notice it
if you get the right combination of overlap and ignition timing you will notice
also try to get hold of a set 10548 camshafts inlet and exhaust ARE the same
these are pre pollution camshafts and do make a difference
If you work on your own cars and have basic tools its not hard to do BUTTTT
IF YOU MOVE A CAMSHAFT TO FAR EITHER WAY THE PISTONS WILL HIT THE VALVE
I dont mean to hijack the thread just thought you might be interested

[Rigi]

True, thanks for that. Changing cam timing and overlap with standard cams CAN give you more power, though as you said there are a number of BUTS. Unless you do change the cams to the 105 cams the difference in minimal VS the risk of bending valves if you get it wrong which is a genuine possibility. Also you really need a dyno to read the absolute benefits as if you get the overlap wrong, you can also loose power.

[carjunky]

I did mine in 1984. just can't remember if it was the inlet or exhaust camshaft retarded by 1 tooth only. An instant 10 hp gain, as Australia had pollution laws then and UK and Europe didn't so the timing on the exhaust or inlet was advanced by 1 tooth and we lost 10 hp.

[prova]

If someone knows exactly what do do I would be really interested and I'm sure heaps of other owners as well. 10hp virtually for free sounds good to me.

[sportiva]

i know how to alter cam timing but you are NOT going to get a 10hp gain
cam timing effects where in the rev range the engine will work best
the idea is to alter both cam and ignition timing to suite your preferences
if you are altering ignition timing and noticing changes in the way the engine responds
then you might want to alter cam timing as well
if both are setup up to work together the results can be very surprising