Originally posted by Diesel Dan:
The AVS series Edeldrock uses a 'quicktune' tunable springloaded air valve to adjust when the secondaries open. But the Q-Jet, Carter and 'original Edelbrock' all use spring loaded air valves, and the air demand of the engine opens them,
Dan the carb in question is a 1404 Edelbrock Performer. The secondary air baffle is a simple counterweighted arrangement. I've dealt with several dozen of them and have yet to find any kind of spring that is used to assist how they open. Maybe I haven't been looking close enough?
To delay the opening you have to lighten the baffle plates by trimming them or drilling small holes in them. To speed up the opening you have to lighten the counterweights. It sure would be a lot simpler if there is a spring to adjust this but there isn't one on these carbs.
The latest carb from Edelbrock is the Thunder Series AVS, Air Valve Secondary, and it does have a spring loaded adjustment so the baffle can be staged to open sooner or later than the secondary throttle plates.
