[elefantrider]

Is running good! This is on a original, low mile CA car. Vacuum pod works.







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[Jack Gifford]

The '57 vacuum linkage closed too slowly- very irritating. Was it better in '59?

[Tom Vaught]

Vacuum Linkage closing too slowly is typically caused by the mechanical Vacuum Switch on the center carb not bleeding the signal line fast enough.

I used to make my own steel vacuum tube to the vacuum pod. I would drill a calibrated hole in the steel tube that would delay the vacuum pod slightly from opening as soon but would also bleed the pod a bit quicker so people did not feel like that had no control of the throttle after an acceleration.
Learned that trick from the WW-II Master Mechanic.
They did make precision vacuum "tees" with a calibration bleed built into them (specifically for emissions calibration devices) in the 70s/80s.
Wish I had kept 100 of the Calibration Tees of different sizes, Jack.

Tom V.

[elefantrider]

It closes OK. Not as fast as a mechanical but it doesn't open too fast for the motor either. Chevrolet used huge Vacuum pods up on the ends of their 427 Tri-power Holley carbs up to '69. I kind of like them.

[Tom Vaught]

Originally Posted by elefantrider

It closes OK. Not as fast as a mechanical but it doesn't open too fast for the motor either. Chevrolet used huge Vacuum pods up on the ends of their 427 Tri-power Holley carbs up to '69. I kind of like them.

They also used a bleed circuit in the end carbs to slow the opening rate of the carbs to a given time then use the same port to open the pods fully.

Let off of the throttles and the bleed circuit helped remove vacuum quickly.

By the way, I have the original Dodge 6-Pack Dyno VACUUM carbs used to set the HP number for the 440 6-pack HP rating.

Tom V.