Purpose of these holes?

[dcdoug]

Originally Posted by Gaz64

Have you taken the carb throttle body off for a look?

I'm thinking the added holes are something to do with creating an "air seal" with the throttle shafts.
In this case there would be intersecting holes going down to each throttle shaft.

It runs all the way through from outside to inside the venturi and comes out in the center above the butterflies. It's separate and above the throttle shaft. There is one for each venturi.

The air seal is sort of an interesting idea, but hard to know how well that woud work.

Mickmate thought they might be something to do with the casting process, but I don't know why they'd go all the way through in that case.

Someone here has to know the answer.

[Tommy]

What follows is an entirely wild ass guess. Is it possible they are part of a system to secure a special air filter or screen to the top of the carb? I can imagine a wire mesh screen (for racing only) secured to the carb with wire arms that hook into the mystery holes. .... As was mentioned earlier, the holes are above the butterflies, so all they seem to do now is let unfiltered air into the carb.

[Gaz64]

Originally Posted by dcdoug

It runs all the way through from outside to inside the venturi and comes out in the center above the butterflies. It's separate and above the throttle shaft. There is one for each venturi.

The air seal is sort of an interesting idea, but hard to know how well that woud work.

Mickmate thought they might be something to do with the casting process, but I don't know why they'd go all the way through in that case.

Someone here has to know the answer.

Yes, I can where it goes, but does it have a vertical drilling down to each throttle shaft?

If it doesn't, then it must be some "engineer's" idea of bleeding off part of the start of the main circuit.

[dcdoug]

Originally Posted by Gaz64

Yes, I can where it goes, but does it have a vertical drilling down to each throttle shaft?

That would be inside the walls of the casting and I can't see in there. Nothing to confirm or dispute this theory from just looking at the hole on the outside and inside of the venturi.