What the heck is this thing?

[Floydsbuick]

What is this rod and lever for? Its Chevy application.

[dcm422]

Dan,
You are probably looking at a 66 carb and that is the 1st generation vacuum break assembly. It is the predecessor of the the plastic one we are familiar with on the passenger side of the carb that prevents the air valve from opening too quickly and causing a bog.


Mark

[Floydsbuick]

Thats darn interesting. This is a picture of a 66 Carb of Ebay. What prompted the question though was somebody showing me a carb with this on it today. But the one I held today was dated 1971. Supposed to be off a 71 396 (402) Chevelle.

[Phil Racicot]

The picture shows a vacuum break on the upper left side, could it be something else?

[Nicholas Sloop]

The picture shows a vacuum break on the upper left side, could it be something else?

I believe on those carbs the vacuum break is still there for choke-related purposes, but does not have its secondary function (pun intended) of controlling the opening rate of the secondary butterflies.

[RAbarrett]

The arm in question is indeed for air valve damping. In the beginning, the vacuum breaks were not calibrated for use as an air valve damper. They were only used for opening the choke. This arm is indeed intended to slow and smooth the air valve opening. Ray