EARLY ZINC CARBURETOR CASTINGS

Many mid to late 1920’s carburetors are included in a group of auto parts (carburetors, fuel pumps, door handles, generator back plates, etc.) made from a zinc alloy (“pot metal”, “white metal”, etc.) that is chemically unstable and therefore not useable. We once submitted a sample of this metal to a metalurgist who tested it and informed us that there was about 4 times the amount of lead in this mix as in the later (about 1935) mix. This material cracks with age and heat.

CARBURETORS WHICH FALL INTO THIS CATEGORY INCLUDE:

Schebler model U

Johnson model H and model R

Marvel (all with zinc alloy bodies 1925~1930,31)

Stromberg model T and model U

Tillotsons from 1923 through 1935

Zenith model 105

THERE ARE NO GOOD ORIGINALS LEFT IN OUR SOLAR SYSTEM!

WHAT CAN BE DONE?

Depending on the application, there may be a number of options available; these options may include:

(1) Replace the castings with castings commercially made from a different metal. The only carburetor from the above list of which I am aware fitting this option would be the Stromberg U-2. New castings have been produced in Australia.

(2) Replace the entire carburetor with a similar model. An example might be the Stromberg UX-2. The UX-2 (zinc) replaced the TX-2 (also zinc), which replaced the OX-2. The OX-2 is brass. Another example would be using a brass 1926~1928 Buick Marvel to replace a 1929 Buick Marvel (zinc).

(3) Replace the entire carburetor with a universal replacement carburetor. This can be tricky, as it is necessary to match the carburetor from both a physical (mounting) and airflow (internal venturi size) standpoint. Also, as some original carbs in this group have rotated flanges (or so horribly inefficient that they may be replaced with physically smaller units) a flange adapter may be necessary. Space requirements of the new carburetor may also be different from the original.

(4) Remove and fabricate a new intake manifold to accept a carburetor that has the correct airflow, but cannot be made to fit due to space issues.

(5) Look at the intake manifold gasket. Some intake manifolds (some Buicks are in this group) may be turned upside down; and a downdraft carburetor (generally with a flange adapter) may be fitted.

(6) Take the old castings to a foundry that specializes in lost wax casting, and have new castings made from aluminum or brass.

(7) Epoxy all the cracks in the existing carburetor. IF THIS OPTION IS FOLLOWED; INSTALL A GOOD AUTOMATIC FIRE ESTINGUISHER, PURCHASE A GOOD LIFE INSURANCE POLICY, AND ATTEND THE CHURCH OF YOUR CHOICE REGULARLY!