Zenith carb ID

[Russell Reay]

I didn't want to hijack Thodge's thread, so here is a new one. Just bought this Zenith core at a swap meet, and have compared all its details to those found in Steve Schmauch's article in the Nov 2022 Restorer. I am not anal about knowing the exact model, but I need to know what I have in order to always order the correct parts and make the correct adjustments. My unit does not match any of SS examples. As shown in the pics the Zenith name is stamped, but there is no number 1, 2, or 3. Additionally, the throat does not have a stamped H or sideways H---it has a stamped Z, and on the back is a stamped E. The back of the bowl has a stamped G, and the back of the choke casting has a stamped D2. Some of SS details suggest this is an early model, and others suggest it is a late model. Anybody wish to venture an opinion ? Most importantly, does it make it any difference???

 

[Thodge]

That looks to be identical to mine. From what I’ve been able to find, the carbs with only Zenith on them are earlier, before they started numbering to identify the manufacturer. My car is a ‘30 but it appears that it was put back together with the drivetrain from a late ‘28/ early ‘29 donor car and this carb could very well be original to that engine. Anyway, it doesn’t really matter as far as parts go. If you were doing a fine point restoration it might matter if it weren’t from the right production window.

 

[Gary WA]

Early Model single venturi, The added numbers took place around mid 1928. The other letters are just a manufactures letters.Those all vary.

 

[fourfords]

Are the two jets in the bowl staggered or in line? If they are in line, it's a 1928 double venturi Zenith carburetor. If they are staggered, then Gary is correct-o

 

[Russell Reay]

Are the two jets in the bowl staggered or in line? If they are in line, it's a 1928 double venturi Zenith carburetor. If they are staggered, then Gary is correct-o

I think you would say these are staggered

 

[Steve Schmauch]

Hello Russell--The reason you can not find an exact match of your carburetor is twofold: first you are trying to use my Holley carb articles to identify a Zenith carb; second, you have a mis-matched Zenith carburetor. Some one had mated a Z10 (Jan-Dec 1930) top (dimple variety) to a Z4 (April-Aug 1928) single venturi bottom casting. One photo shows the brass float mechanism--a view of the air mixture boss would tell me for sure if it has a cup instead of a brass plug on the top casting. If it has a cup, then the top would be a Z11 (Jan-Mar 1931). Many carbs available today have mismatched parts as most Zenith, Holley, and Ford parts are interchangeable.

No Zenith or Holley carbs were identified with 1 or 2 until January 1, 1929, not "around mid 1928" as mentioned above. Please see my article in The Restorer in the July-August 2017 issue, pages 8 and 9 for the explanation of when and why these numbers were added.

I have not been able to find out information about manufacturers G or E. The E manufacturer started and replaced manufacturer G in 1931. The other numbers/letters found in various locations on the castings refer to internal manufacturer batch and mold numbers possibly for inventory or recall purposes.

 

[Russell Reay]

"a view of the air mixture boss would tell me for sure if it has a cup instead of a brass plug on the top casting." Mine definitely has a plug--your fig 2, and the bottom casting is H23 per your Fig 7. Doesn't surprise me that the carb is a combination of two old units. Thanks for the clarification

 

[Steve Schmauch]

H23 is a 1931 Holley carb. Your carb bottom does not say "Zenith-2", it says "Zenith" only, so your carb (top and bottom) are Zenith carburetor parts.

Look at the dowel pin bosses (critical feature no. 8) and the shape of the area below the GAV boss (critical feature no. 7) on your carb bottom. You will see that your carb bottom exactly matches my Z4 identification. Please look at The Restorer May-June 2017, page 9, figure 4.

Glad to help you out and thank you for your interest in wanting to correctly identify your carb pieces!

 

[dlshady]

H23 is a 1931 Holley carb. Your carb bottom does not say "Zenith-2", it says "Zenith" only, so your carb (top and bottom) are Zenith carburetor parts.

Look at the dowel pin bosses (critical feature no. 8) and the shape of the area below the GAV boss (critical feature no. 7) on your carb bottom. You will see that your carb bottom exactly matches my Z4 identification. Please look at The Restorer May-June 2017, page 9, figure 4.

Glad to help you out and thank you for your interest in wanting to correctly identify your carb pieces!

Steve,

Could you please list any issues of The Restorer or Model A News with your articles? I quite a few carbs halves that I would be interested in mating up to their correct other half.

Thanks!

 

[Steve Schmauch]

Here is the list of issues in The Restorer magazine that contain my detailed articles on Zenith, Ford, and Holley carburetors:

ZENITH CARBURETORS

V. 61, issue 6, Mar/Ap 2017 pages 8-14: 1927 Zenith Carburetor
V. 62, issue 1, May/June 2017 pages 8-9: 1928 Zenith Carburetors
V. 62, issue 2, July/Aug 2017 pages 8-11: 1929 Zenith Carburetors
V. 62, issue 3, Sep/Oct 2017 pages 8-11: 1930 Zenith Carburetors
V. 62, issue 4, Nov/Dec 2017 pages 8-14: 1931 Zenith Carburetors

The last 2017 issue includes detailed information on the Ford carburetors and the similar-looking post-production Zenith carburetors. The post-production (aftermarket) carburetors are especially hard to identify as they include early AND late features combined.

There are 15 recognized varieties of Zenith, 3 Ford, and 21 Holley carburetors, used during production of the Model A Ford.

I think the most helpful article is titled "The Holley Carburetor's Critical Features", published in The Restorer V. 67, issue 4 Nov-Dec 2022, pages 14-20. In this article I explain and show how each of the 8 Critical Features I used changed throughout production. Once a person becomes familiar with those features, one or two of them can be quickly observed and makes for rapid identification. Note this article is on Holley carbs but almost all of those same features apply directly to the identification of Zenith carburetors, just slightly different time periods of use.

As a side note, when I was conducting my research I looked at 32 differences that appear on the carb castings. It was a difficult process digesting all that information to come up with 8 features that make it easy for a person to learn and use for rapid identification. It is just like when the hobby learned the difference between an early 1928 (AR) wheel and a later 1928 21 inch wheel. Once you know what feature(s) to zero in on, you will be able to identify the year or range of months a particular carburetor was used.

I think the Holley Identification Chart (on page 20) combined with the generic carb I used for showing the locations of the 8 Critical Features will be most helpful to you. The Zenith Identification Chart is found on page 8 in the 1931 Zenith article.

HOLLEY CARBURETORS

V. 67, issue 4, Nov-Dec 2022 pages 14-20: Holley critical features explained
V. 67, issue 5, Jan-Feb 2023 page 20: 1927 Holley Carburetor
V. 67, issue 5, Jan-Feb 2023 pages 21-24: 1928 Holley Carburetors
V. 67, issue 6, Mar/Ap 2023 pages 12-14: 1929 Holley Carburetors
V. 68, issue 1, May/June 2023 pages 14-17: 1930, 1931 & aftermarket Holley Carburetors

 

[dlshady]

Here is the list of issues in The Restorer magazine that contain my detailed articles on Zenith, Ford, and Holley carburetors:

ZENITH CARBURETORS

V. 61, issue 6, Mar/Ap 2017 pages 8-14: 1927 Zenith Carburetor
V. 62, issue 1, May/June 2017 pages 8-9: 1928 Zenith Carburetors
V. 62, issue 2, July/Aug 2017 pages 8-11: 1929 Zenith Carburetors
V. 62, issue 3, Sep/Oct 2017 pages 8-11: 1930 Zenith Carburetors
V. 62, issue 4, Nov/Dec 2017 pages 8-14: 1931 Zenith Carburetors

The last 2017 issue includes detailed information on the Ford carburetors and the similar-looking post-production Zenith carburetors. The post-production (aftermarket) carburetors are especially hard to identify as they include early AND late features combined.

There are 15 recognized varieties of Zenith, 3 Ford, and 21 Holley carburetors, used during production of the Model A Ford.

I think the most helpful article is titled "The Holley Carburetor's Critical Features", published in The Restorer V. 67, issue 4 Nov-Dec 2022, pages 14-20. In this article I explain and show how each of the 8 Critical Features I used changed throughout production. Once a person becomes familiar with those features, one or two of them can be quickly observed and makes for rapid identification. Note this article is on Holley carbs but almost all of those same features apply directly to the identification of Zenith carburetors, just slightly different time periods of use.

As a side note, when I was conducting my research I looked at 32 differences that appear on the carb castings. It was a difficult process digesting all that information to come up with 8 features that make it easy for a person to learn and use for rapid identification. It is just like when the hobby learned the difference between an early 1928 (AR) wheel and a later 1928 21 inch wheel. Once you know what feature(s) to zero in on, you will be able to identify the year or range of months a particular carburetor was used.

I think the Holley Identification Chart (on page 20) combined with the generic carb I used for showing the locations of the 8 Critical Features will be most helpful to you. The Zenith Identification Chart is found on page 8 in the 1931 Zenith article.

HOLLEY CARBURETORS

V. 67, issue 4, Nov-Dec 2022 pages 14-20: Holley critical features explained
V. 67, issue 5, Jan-Feb 2023 page 20: 1927 Holley Carburetor
V. 67, issue 5, Jan-Feb 2023 pages 21-24: 1928 Holley Carburetors
V. 67, issue 6, Mar/Ap 2023 pages 12-14: 1929 Holley Carburetors
V. 68, issue 1, May/June 2023 pages 14-17: 1930, 1931 & aftermarket Holley Carburetors

Steve, I really appreciate the list. Looks like a few of those were published during the years I let my membership lapse, so it's off to eBay I go!

Thanks!

 

[Steve Tx]

Thanks for thise articles. I purchased a full set of 2017 issues just to get the carb articles. Worth every penny.