Can anybody offer up a guess what these are intended for? This base is from a 3x2 primary carb, it has a single .105 hole drilled (see my plug gauge) The 2 end carbs have 2ea .085 holes drilled, see the plug gauges inserted in the drilled holes: These holes are ABOVE the throttle blades, they only see vacuum when the throttle is opened, what purpose are the serving? Thanks, Oj
To what purpose, what condition are they trying to correct? It wouldn't be a vacuum leak unless the hole was drilled below the throttle blades.
I have never noticed anything like that on any of mine. I am going to guess they should not be there at all. If someone wiser does not set this straight before then, I will inspect mine when I get home later today. I have a set of 3x2 bases from Charlie Price.
Those holes are NOT...vacuum leaks !! To be a vacuum leak, they'd need to be "under" the butter-flys, NOT above. As to the "exact" reason they are there, I was not part of the design team, so...I don't know. People can guess as much as they like, but I'd like to hear from a design team member... Mike
Had a set of original Pontiacs (avatar)and no holes. Guess: keeps fuel pressure even across the set, blades open and still even and smooth. JB weld cures teeth and these.
Holy shit, thats my own thread! damn, I do not remember that. Well, that answers that, yes this is a different set of carbs, very professionally done - well, other than not working (I've found that they had aftermarket floats that were too long by a few thousandths and wouldn't let the float shut off the needle & seat, the float rubbed the fuel tower for the accelerator pump).
See Doug Roe's Rochester Carb book, pg. 68. Those are factory holes for hot engine start vapor release. A vented gasket was also used. No more holes after 1970-71, emissions reasons . Leave as is or plug if you want.I leave them open.
The Jalopy Journal
