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123 ignition curve for Spider 1600, 1988.

4651 Views 2 Replies 2 Participants Last post by  michalmarianek
I just bought the 123ignition ALFA-4-R-V for Alfa Romeo Spider (1988) with a 1600 litre engine and Weber carbs. Now I am looking for a fitting curve.

The ref-nr. of my original distributor is jfu4.

Unfortunatelly this Boshnr. is not mantioned in 123ignition for Alfa.

0, Giulia Nuova 1300 - 1600
1, Spider 2000, Bertone 2000
2, Giulia TI
3, Giulia TI
4, Duetto 1600
5, Giulia Super, Giulia Sprint
6, Giulia GT, GTC
7, JF-4 Giulia Super 1300-1600
8, Spider 1750
9, Bertone 1750
A, used by Alfa from ’72 to ’78
B - -
C - -
D, 006-’tuning’ for high compression, ’hot’ cams
static timing 12 degr. ; max. advance 34 degrees
E, Shankle-#4255 another popular curve amongst tuners
steep until 13 degr. @ 1300 rpm, then towards max. of 32 degr. @ 4000 rpm.
F, Marelli S103 & S166 steep until 13 degr. @ 1600 rpm, the towards
max. of 36 degr. @ 5000 rpm.

Can anyone help ?

Thank you very much
Michal Marianek
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1 - 3 of 3 Posts
What may be an issue is that the original 229 distributor has a vacuum advance in addition to the mechanical advance. Assuming the vacuum advance receives manifold vacuum (vacuum rises as throttle closes), then this is would aid fuel economy and emissions. If one disregards the vacuum advance, then curve 'A' on the 123 distributor is virtually identical to the mechanical curve of the 229.
If the vacuum advance receives ported vacuum (vacuum rises as throttle opens but only til about half throttle), then 123 distributor curve '5' or 'E' may be more suitable.
Hello Jim
Thank you very much for help. I selected "E" curve and my car runs like never before!
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