Not only did the carburetor design change often, it was manufactured by three corporations.
Who manufactured this carburetor?
- The carburetor was manufactured by the Zenith-Detroit Corporation, Holly Corporation, and Ford Motor Corporation, for use on Model A Ford vehicles produced in the United States and Canada. It's not too well known that this Zenith design was also manufactured in England as the Kayce carburetor and in the USSR as the GAZ carburetor. However, the Kayce and GAZ carburetors are almost never seen in the United States. So, we are ignoring them on this website.
- Zenith manufactured the carburetors for Ford from about August of 1927 through 1931. All of their top castings were marked with a "Z" just below the throttle. The bottom casting were marked on the front of the bowl area with "Zenith" from the beginning through 1928 and with "Zenith-1" from 1929 through the end of production.
- Holly manufactured the carburetors for Ford from about August of 1927 through 1931. Their upper castings were marked with "H" from the beginning until about September of 1928. Thereafter, they were not marked. The bottom castings were marked with "H" from the beginning to about June of 1928. From about July through December of 1928 they were not marked and from January 1929 until the end they were marked "Zenith-2".
- Ford manufactured carburetors from 1930 through the end. For a while the upper castings were marked with "3", but it was soon dropped. The bottom castings were marked "Zenith-3".
- Other than the above markings there were some miscellaneous foundry markings
- Photos of the variations in carburetors made by these manufacturers can be found on some of the websites, found at Model A, Zenith Carburetor Photos.