list it on craigslist or ebay for 100$ obo if its completely rebuilt (not just cleaned up with new gaskets) and see if anybody talks to you about it and then take any offer above 50$
they aren't worth much but there are the right people out there, i've got 1 just like yours i can't get rid of and 2 late 70's model non cc i dont know what to do with
Quadrajets are a dime a dozen, because most people favor the Holley or Edelbrock variety of bolt of performance carbs. Truth is, the Quadrajet is the best of both worlds, granting both efficiency and performance. Granted, they are more difficult to tear down and rebuild than the basic Holleys or Edelbrocks, but well worth the effort. Just my opinion, members, don't go off on me.
It's probably a non computer controlled variable venturi with electric choke, would be my guess, and more than likely from a pickup. But that's just me guessing...........
Yeah, the variable part is the butterflies for the secondaries. They open only enough to give the engine what it needs so far as air/fuel mixture, rather than just dumping in a bunch of gas and sucking in air in open ports, like the "performance" carbs do.
That isn't "variable venturi", that's "air valve". All q-jets have the air valve feature, whether computer controlled or not, electric choke, hot air choke, divorced choke.
NOUN:
pl. ven�tu�ris
A short tube with a constricted throat used to determine fluid pressures and velocities by measurement of differential pressures generated at the throat as a fluid traverses the tube.
A constricted throat in the air passage of a carburetor, causing a reduction in pressure that results in fuel vapor being drawn out of the carburetor bowl.
Thus, as the butterfly valve on the secondaries opens per engine cylinder requirements, a variable cfm of air pulls the appropriate amount of fuel through the venturi, regulated by the metering rods attached to butterfly. Has nothing to do with the choke.
The first function of the air valve is to restrict air flow until the fuel flow catches up. After that, it's basically a mass air flow system - the more air mass flowing through the secondaries, the more the valve opens up, and the more fuel is added to the air stream.
Ford had a true variable venturi carb in the 70's smog era. It was even called "variable venturi". It was also very troublesome.
Since all quadrajets have it, it's completely, totally, and utterly moot to describe it as a variable venturi carb, since we can assume it is a q-jet from what the original poster called it (and if that was in question, we could ask for a description of it, using the above-linked sticky as reference - in which case, we would be asking if it had the air valves, not if it was variable venturi secondaries).
For the record, you brought up the choke ("variable venturi with electric choke"), not me.
And, for the record, the choke pull-off (vacuum break) does also restrict the opening of the air valve. But, again, that isn't limited to any particular type of q-jet.
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