Zenith B Carburetor Diagram

R

Richard Lorenz

Senior Member
Paul Moller presented a drawing / diagram of a Model B carburetor, but it has an error in it.

Has anyone else made a sketch of the internal construction of a B carburetor?
 
Re: Zenith B Carburetor Diagram- Error in Model B diagram corrected in 2004

Gordon Biggar and Rex Reheis found an error in a diagram in 2004 while researching their book.

This is discussed on page iv in the forward to their book.

George De Angelis corrected error in the diagram as published on page B-3 in this book.

The corrected version has "G.D. 04" in lower right corner under the bowl. See page B-3 in Biggar / Reheis book along with text on page B-2.

Two passages are / were reversed.

The error appears in several books over the years.

additional info added since original posting ...
 
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The Moller diagram has the Main and Cap Jets joined directly together by a line that should be cut off close to the main jet. The main jet then needs to be shown with a fuel supply directly from the bowl.

The De Angelis drawing as shown on page B-3 of the Bigger book looks good except that it would be nicer if a line had been shown going directly from the bowl to the bottom of the main jet. There is room for this line to be drawn in by hand, probably with a red-ink pen so that it will show up.
 
Richard Lorenz said:
The Moller diagram has the Main and Cap Jets joined directly together by a line that should be cut off close to the main jet. The main jet then needs to be shown with a fuel supply directly from the bowl.

The De Angelis drawing as shown on page B-3 of the Bigger book looks good except that it would be nicer if a line had been shown going directly from the bowl to the bottom of the main jet. There is room for this line to be drawn in by hand, probably with a red-ink pen so that it will show up.
Click to expand...


It was 14 years ago that I looked at this but as I remember one thing wrong was that the Comp and Cap jet were reversed in original De Angelis diagram.
 
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There is a serious error in the De Angelis drawing G.D. 04 on page B-3. The Cap Jet is drawn completely wrong. There are no side holes in the Cap Jet, and the "restrictor" (Jet) end should be at the top.

As far as I know, the Cap Jet for the B carburetor is the same as that used in the Zenith-1 and Zenith-2 carburetors that are standard with the Model A Ford.
 
Most of my experience is with the Model A carbs but rennerscorner website clearly shows the Model B Cap jets to be different from Model A.

FYI:

All Model B Cap jets I have seen are different from Model A ones.

http://rennerscorner.com/carburetor.html

see SECOND JET set RC-9501-32 on the page above. click on photo to enlarge.



Richard Lorenz said:
There is a serious error in the De Angelis drawing G.D. 04 on page B-3. The Cap Jet is drawn completely wrong. There are no side holes in the Cap Jet, and the "restrictor" (Jet) end should be at the top.

As far as I know, the Cap Jet for the B carburetor is the same as that used in the Zenith-1 and Zenith-2 carburetors that are standard with the Model A Ford.
Click to expand...
 
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I have 25 cap jets in my "extra parts" collection. They are all the same and they fit both the B carb and the Zenith 1 and 2.

I will ask my grandson to help me learn how to transfer pictures into Ford Barn. Do you know of a good explanation how to do this that is posted somewhere?
 
this help?
 

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Gary: Thanks for the pictures. The first figure is identical to the Moller drawing that I mentioned above. Even though it is from a 1932 Service Bulletin, it is wrong. The comp and main jets are not joined. The full picture has an Index on the left side which states that item "I" is the feed to the main jet, but the drawing shows it feeding the GAV.

The third figure (view from above) shows the location of I correctly. You can barely see "I" at the bottom of the picture. It is an unrestricted opening to the main jet, and is not joined to the GAV / Cap Jet System. Also, the Cap Jet is shown upside-down in the drawing.

I blew some air through some of the openings in one of my B carburetors. This blowing agreed with what I said above, but was not good enough to actually prove everything that I said.
 
Gary WA said:
this help?
Click to expand...


The plot thickens ... !

AS I mentioned above the Cap jet and comp jet names in the Model B carb appear to have been changed compared to Model A carb.



1. The third diagram in post #10 from 32 SBs shows H as the "Cap jet" this is the location of the comp jet in Model A carb isn't it ?



2. The third diagram in post #10 from 32 SBs shows F as the "Compensator Tube" this is the location of the CAP jet in the Model A carb isn't it ?


Seems that Zenith changed the names of the two jets / "tubes" ... Ain't so? ... beaucoup dien cai dau !
 
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Benson: You are correct about the jet identifications that the 1932 Service Bulletin diagram shows.

The De Angelis drawing that I mentioned previously uses the traditional names for the jets. It will take me at least a week before I can get help to post pictures.

In the mean time, I hope that someone else will join this discussion.
 
I apologize. I was just now in the process of assembling a "B" and discovered that the Caps are not the same as in Zenith 1 & 2. I then looked around and found my container of spare B Caps. Sorry for my error. Richard Lorenz
 
Zenith B Carburetor by George De Angelis. Red lines show improvements or correction.
 

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The first picture shows an unusual Zenith B-2 circular Idle inlet along with the notched throttle plate. This carburetor has a smooth bowl top. Most tops have depressions in the top of the bow. The second picture shows a comparison of the two tops.

Sorry. The pictures did not come up. I will try again in a few days with my grandson's help.
 

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As I remember from many years ago.

The B carb type B-1 has a hole in throat like Model A AND requires the notch in the plate.

THe B carb type B-2 has a brass plug with a slot instead of a hole where idle port is. This B carb does NOT use a NOTCH in throttle plate.

A number of B carb types have the wrong plates installed in them.
 
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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.
 
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