 123 Switch Distributor, Which curve? |
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| NotLance |
 Nov 11 2025, 05:35 PM
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#1
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Member  Group: Members Posts: 94 Joined: 4-February 21 From: Northern California Member No.: 25,165 Region Association: Northern California  |
Hello! I've got a carbed -4 2.0l and have the 123 distributor with 16 curves.
When engine was set up it was set using standard timing for these cars (Which I think is 10 to 17?) Can't remember off the top of my head but whatever the mark on the fan is at) Which setting on the distributor should I use? I cant find any solid sources for this distributor. It was at B when I got it - and has been left at that since.  And while I'm asking all these questions, does anyone know what DEGREES NEGATIVE VACUUM !!!!! is and if I need one of those settings or not - it was set on one so I assume I do but idk. I do not know anything about timing, but want to learn! |
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| emerygt350 |
Nov 11 2025, 07:29 PM
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#2
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Advanced Member Group: Members Posts: 3,383 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
Yikes..since you have a 70 and it is a carbed 2.0 4 I have no idea what is actually in your engine bay, however, b is probably not what you want. That degrees negative is a retard used on later engines at idle and decel to reduce emissions. And if your 123 isn't hooked up to a vacuum source (please tell me it isn't) it doesn't really matter.
Set it to 1 and if you do have ported vacuum on one of your carbs you could attach the vacuum to that but be sure it is ported. At idle you should feel no vacuum on that line (from the carb). Don't feel like you have to use that advance though if you are unsure about ported vacuum. These work great without it. 1 shouldn't feel any different as long as you were not running vacuum to the distributor. If you were, and it was ported, 1 will feel like a new car |
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| NotLance |
Nov 11 2025, 07:50 PM
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#3
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Member Group: Members Posts: 94 Joined: 4-February 21 From: Northern California Member No.: 25,165 Region Association: Northern California |
Should have specified a year! Its a GA case
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| emerygt350 |
Nov 11 2025, 08:21 PM
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#4
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Advanced Member Group: Members Posts: 3,383 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
QUOTE(NotLance @ Nov 11 2025, 07:50 PM)  Should have specified a year! Its a GA case Then absolutely 1 is what you want. Are you running a vacuum line? |
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| JamesM |
Nov 11 2025, 09:03 PM
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#5
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Advanced Member Group: Members Posts: 2,150 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
QUOTE(NotLance @ Nov 11 2025, 03:35 PM) And while I'm asking all these questions, does anyone know what DEGREES NEGATIVE VACUUM !!!!! is and if I need one of those settings or not - it was set on one so I assume I do but idk. " DEGREES NEGATIVE VACUUM !!!!! " Is their way of saying vacuum retard. Stock injected 914s are all setup this way , it is used to bring down engine speed at idle. Also gives faster response off idle as stepping on the gas results in immediate increase in advance regardless of RPM. |
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| NotLance |
Nov 11 2025, 11:32 PM
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#6
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Member Group: Members Posts: 94 Joined: 4-February 21 From: Northern California Member No.: 25,165 Region Association: Northern California |
Good info - and no, I’ve got the one without a vacuum line, I believe it’s 4-R
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