Thread: Vacuum advance
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Old 02-15-2023, 03:57 PM
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Kenth Kenth is online now
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Quote:
Originally Posted by Formulajones View Post
I've found that with a good custom ignition curve I don't need to get as aggressive with carb adjustments, even on today's fuels. In fact most cars I deal with complaining about carb problems are fixed with a good ignition curve. I always start there first and won't even begin carb tuning until ignition is dialed first. A good ignition curve especially helps tip in and off idle transitions so I don't have to go crazy on pump circuit changes.

Then I'll drive into enlarging idle feed restrictors and what ever else might be needed.

I see people all the time approach this the other direction and really get the carb so far out of whack it's a whole bunch of effort to fix. Most of those instances the carb gets blamed.
I have found igniting a too lean A/F mixture with timing out of the scale the engine wont reach itīs full potential.
I prefer to use close to factory ignition curves as they are a part of engine design parameters and add the required amounts of A/F mixture needed for best performance, driveability and economy.
The timing settings out of the scale or "all in" at 2000 rpmīs, usage of multispark systems are all remains of the past.

Over the years, it has always been more difficult, as well as the lack of knowledge among the general public, to modify the carburetor's low-speed circuits, many have not known how this worked or even that they existed. Instead, they have gone to the ignition, as it is easier to turn the distributor, and mount weaker springs at the weights.

FWIW

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Last edited by Kenth; 02-15-2023 at 04:05 PM.
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