Secondaries opening?

[fnaramore]

Hey, I have an edelbrock 1406 carb and I was curious if anyone knows how to check if the secondaries are opening properly? Also, between the distributor and timed port on the carb, there is this little black box that the vacuum connects to. Does anybody know what this is? what happens if I bypass and connect my dizzy straight to the carb? This is all on a 318 in a 73 swinger

 

[burdar]

The box is probably the vacuum control valve. It delays the advance for emissions reasons.

 

[fnaramore]

So there is no danger in hooking up the vacuum advance on my distributor straight to the timed port on my carb?

 

[rumblefish360]

On a Edelbrock carb, looking at the front of it, hook the distributors vacuum advance hose to the lower right nipple directly from the distributor. The black box is a delay box for emission reasons. IIRC, it delays spark advance by 15 seconds.

To check if the secondaries are opening all the way, with a friend and the engine NOT RUNNING, have your buddy depress the gas pedal to the floor. You will look down the carbs secondary side and open the secondary sides air velocity flap, the counter weighted door. A pencils eraser is a good help.

The AFB's are a mechanical operating secondary all the time with the counter weighted air door above it that opens upon demand of more air flow.

Should the pedal NOT open the secondaries all the way, adjust how the throttle cable sits in the clamp on the manifold. Move it rearwards towards the fire wall.

If your wondering if it opens all the way when your driving, it does so long as the above is working properly.

 

[fnaramore]

Okay cool!! thanks a lot rumblefish! Just to check though, so hook it up to the non-timed port on the carb? Because if I recall correctly, the left one is timed and the right one is manifold vacuum.

 

[burdar]

Hook it up to the timed port. It will be the one above the throttle blades.

 

[65Val]

Hook it to the port inside the orange circle....