Ford Holley 94 Carburetor question

P

psogden

Member
On the top piece of this carburetor (the one that receives the fuel), there is a small rectangular hole below where the air cleaner attaches. It is at the top of the fuel chamber. I assume this is an overflow hole. I was bothered that sometimes gas spews out of this hole and might pose a fire hazard. I removed the top piece from the carb and cleaned out the needle valve. This stopped the “spewing” which I assume was caused by a high float level. On a 94 carb core that’s been kicking around in my basement for years, I observe there is no such hole. Can any of you 94 experts clear this up? Why is it that some carbs have this hole and some don’t? And what purpose does it serve? Thanking you all in advance.
 
The hole you refer to is a vent, and should not be plugged under any circumstances. The vent location was changed due to the same observation you had, that being the fuel spewed out at times. The first change was to a location on the opposite side, a horizontal hole angled slightly inward, through the upper accelerator pump housing, directly into the upper float bowl. As this location also proved less than perfect, the final location was by way of a tube angled upward within the air horn itself. These changes occurred over a period of several years, all air horns interchangeable with each other regardless of where the vent is.
 
Yes X 3. Don't plug it. Carburetors do not have overflow holes. It's part of the bowl vent system.

Sal
 
To clarify...if this is the external vent it is a vertical slot (actually a long oval) through the side of a sort of rib going up the front of the air horn. many later carbs have a shallow cast depression there marking the location of the early vent, unopened.
 
I now understand and very much appreciate everybody responding. Also, Ken Isidor, who responded by email, was very helpful. Lot to learn about these old V-8s. Good to have this forum. Thanks.
 
There are a few variations on the vent. The reason it finally went internal was because the float level was affected by air pressure changes around the carb (caused by fan wash etc as the fans became bigger and more efficient)
 
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