I am running two 2g's, and am having problems getting the vaccum advance to advance right off of idle. I have constant vaccum coming from both carbs, and so when you rev the motor off idle, there is a slight studder, and then it picks up. I thought that the carbs vaccum in the 2g's were supposed to be little to no vaccum at idle, and then get greater as the rpms increased. Any help would be great.
Sound like you need a little more initial timing to make up for the momentary drop in vacuum which is retarding the timing as soon as you open the carb.
I am already running about 8 degrees above top dead. I have tried to change timing up and down, but it doesn't seem to make a big difference with the vaccum gauge out of the carbs.
No that is incorrect. Even though the vac advance comes off of the carb body up high, the passage inside the body goes straight down and comes out below the butterflies. It is actually manifold vacuum. That is why it is necessary to disconnect and plug the V.A. tube when setting the initial timing with a light. There is a big myth about "ported vacuum" but there never has been a place to get ported vacuum from a Rochester 2bbl.
Thank you for the replies, one question that I have, is should I spend the money for a centrifical dist, or will the vaccum advance one work?
Your distributor should have both centrifugal and vacuum advance. You can choose not to use the vacuum advance at all if you wish.
If it's going to be predominantly a street engine, keep the V.A. and use the stock timing specs. Disconnect the V.A., plug the hose or tubing and then set the timing with a light. Then reconnect the V.A. and you are all set. The V.A. will give you better MPGs at cruising speeds.
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