Zenith B Carburetor Diagram

[ursus]

I Have 3 of the carburetors that use the small circular opening for the idle outlet. These 3 have large
Z" embossed on the throttle side. I just discovered that the were built to use the round B-1 style float. The rectangular float cannot be used. I also have 9 other "Z" carburetors that can use either style float and all 9 have the common brass-slit style idle opening.

This suggests that the style with the circular idle outlet might b the first B-1 type.

I believe you are correct regarding the idle port design on the first B-1 type. What is still confusing is that your revised drawing shows the "missing" passage to the main jet from the float bowl reservoir yet this is actually the "I" passage depicted on the original Ford drawing. The flow rate via this passage is controlled via the GAV but your rendition seems to neglect this factor. The DeAngelis drawing is a bit cattywompous as it shows two aspects of the float bowl that are out of alignment with the passageway and jet configurations. I still think that the Ford drawing is basically correct except for the false passageway linking the main and cap jets to the same 'I' drilling, which is not the case in an actual carburetor.

 

[Richard Lorenz]

I have 3 of the "small circular hole"type carburetors, but I have 9 B-1 carburetor bottoms. This suggests that the "hole" type carburetor lasted only part way through the B-1 duration.

Gordon Biggers discusses the B-1 idle "hole" type on pages B-1 and B-2 of his book, but he states that the "hole" type was not changed until the B-2 design was started. I believe that some B-1s used the brass slit type idle entrance design.

I have assembled a "hole-type" B-1 carburetor and will try it on a car when I get a chance. I could not find any information about setting the float level. Does anyone know where the float level should be set?