vacuum advance

[wdwrlw]

Have always ran my mildly built 360 with no vacuum
Advance. I decided to hook it up and it wouldn't even make
It out the driveway. The popping was horrible. I have a
Comp h170. And edlebrock 750 carb. Timing was at 12 deg
Initial, then went low as 8 deg and up to 17-18 deg. It just
Popped the moment you lifted told off idle. What could cause this.
I currently just leave it plugged up and it runs just fine. But
Am very curious as to why it run so irratical when vacuum advanced.
Is hooked up. It's a jeep. I don't get into the total adv and all that.
Ant thoughts?

[tufcj]

Personally, I prefer no vacuum advance on a performance engine. Vacuum advance was created for drive ability and mileage. I run my AMX at 18 initial and 36 total (all in by 3000) with no vacuum.

Is your vacuum hooked to manifold or ported vacuum? Manifold vacuum will max out at idle and when you take your foot off the pedal. Depending on how much vacuum advance your distributor allows, you could have way too much advance for conditions. Ported vacuum (usually on the side of the cab) will increase as air flow increases.

Do a search, there's a whole thread on ported vs. manifold vacuum.

Bob
tufcj