Thread: Qjet vacuum ports question

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Thanks Denny, I did not mean to second guess what you were saying, I'm just trying to learn it for myself. I super appreciate the help and walking me through it.

OK, so the choke pulloff is incorrect, I will fix that.

I do have light advance weights on my HEI, yes.

Here is how I understand vacuum advance, correct me where I am wrong: As rpm's go up, ported vacuum goes up, manifold vacuum goes down. When the vacuum advance unit on an HEI gets vacuum pulled, the timing is advanced. When the unit sees no vacuum, there is no additional vacuum advance. Therefore (I thought), that as the rpm's go up, you need and want additional timing (above and beyond the weights).

I am perfectly willing to try using manifold for vac advance as long as I understand why. In fact the guy who rebuilt the carb is coming over this weekend to help me dial it in, and he suggested Manifold vac too.

So if I were to switch over to manifold vac for distributor, should I keep the light weights? (my prime powerband is 2000-4000)

Edit: I found these pics on Ebay to see some more vac examples of pull -off (as you said).