Edelbrock Performer Carbs do not have vacuum secondaries!
I see the Edelbrock Performer carbs called vacuum secondary carbs all the time. They are not.
For info here is a good article on how four barrel carbs work. Below is how the Holley vacuum secondaries work from this RodandCustomMagazine.com article (Click here to see better pic) :
The Edelbrock performer does not use the vacuum method. The secondary butteryflies are controlled with your foot in a progressive linkage. There is an additional butterfly called an air valve over these that controls the rate air tips into them. This air valve is weighted in the standard Performer Carbs to acheived this effect.
From Edelbrock.com:
The Edelbrock AVS series carbs give you the ability to adjust the air valve tension with the turn of a screw.
From Superchevy.com:
The primary side of the Edelbrock carbs do have a vacuum metering affect. The metering rods have 2 tapers on each rod. The fat part of the rod is normally in the jet at high vacuum. The high vacuum holds down the rod against the rod spring which are available in different colors with different strengths. When you open the throttle and get a low vacuum the spring pushes the rod up so the thin part of the rod is now in the jet and allows more fuel to flow and get a richer mixture for better performance.
In conclusion, the Edelbrock Performer carbs are more correctly a Vacuum Primary carb and are in no way a vacuum secondary one.
How well you or a friend sets up the carb will determine your ultimate success. They all seem to have their problems and virtues. Plenty of successes and failures for any carb you can find.
