Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Confused about carbs, need help!
View Single Post
  #39 (permalink)  
Old 01-20-2013, 06:05 AM
cobalt327's Avatar
cobalt327 cobalt327 is offline
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by CHEVILLAC View Post
Ok, I know ported vacuum for the vacuum advance is hooked to the carb so I'm guessing it is operated in a similar way as the vacuum secondaries, otherwise a motor that has very little manifold vacuum wouldn't be able to operate the advance. If the motor runs well as it is, what would be the advantage of adding the vacuum advance back into the equation? Will it be better for for driving conditions between idle and WOT?
Ported vacuum (passenger side vacuum port on the Edelbrock carb) is only there when the throttle blades are opened. When closed, no vacuum. What that means when applied to a vacuum advance is there will be no added advance at idle. You already have a high enough amount of initial advance (or you should have, like 20 degrees-plus) for the engine to idle well w/that cam, so no additional advance is needed, or wanted.

The vacuum advance will only add advance to your engine at light throttle/light load conditions. This helps the engine to run smoother, maybe a tick cooler, and will use less fuel. There are no downsides to using it- as long as it's done as I've outlined.

Once you get it running, check the initial and total advance to be sure it's what it should be.
Reply With Quote
The Following User Says Thank You to cobalt327 For This Useful Post:
CHEVILLAC (01-20-2013)