Racing Fuel Systems

Mark,
Question is about Carter carbs. Posted here because I am not sure if you look at the other sections. Answer will be probably be of interest to all carb users.

Restoring a Carter 750 AVS that is OEM for a 1968 440 Dodge engine. The primary boosters. The booster leg, from the main body to the aux vent has an alum boss on the underside of it that is an open hole. There is a small hole from it, 0.020-0.040", [ did not measure it ] drilled into the brass discharge tube. Any idea of the purpose of this? Have seen this on other Carter models. Thanks.

Any photo of it? This is a primary cluster, right? and each primary cluster has the same hole?

Yes & yes.

You aren't looking at the idle ckt are you? It 'crosses over' in the cluster and feeds to an hole in the body drilled at an angle to intersect another passage going to the idle screw, the intersection has that rivet plug in the front of the carb.

No, nothing to do with the idle cct. If you want to PM me an email address, I can send you a pic.

I don't have much time with Carters, I'll see if I can get Tuner on the post.

is this what your looking at?

Nope.

If you look at the arm that connects the booster ring to the main body, you can clearly see a round boss in the aluminium about half way along the arm. Sometimes that boss is drilled, all the way up into the brass discharge inside the arm.

Picture of 1966 Chrysler AFB 4131s with .039" drilled into primary booster tube.
Picture of 1968 Chrysler Holley list 4166 with .030" drilled into primary booster. I have two of these here.
I think this is a Chrysler OEM deal. Can't explain it but here are my thoughts. An air passage into the primary booster may add air for better atomization but one would think this would also delay the start up of the fuel delivery to the primary booster. Maybe someone on here can can explain this

Yes, that is the hole: in the Carter booster.