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The Place for Model-A Ford Carburetors


Venturi (Single and Double)
  • The Venturi is a tube, which narrows to a small size and then widens out again, which increases the speed of the air rushing through the carburetor, and lowers its pressure. The higher air pressure in the float chamber then forces gasoline through the jets into the Venturi.
  • The double Venturi was used from the start of production through June of 1928, and the single Venturi was then used until the end of production.
  • The original, single Venturi had a .843" diameter throat, but many of the original Venturies are now warped from heat.
  • Many of the newer Venturies, which are made of pot metal, measure .835 or less, and many have throats that are egg shaped by .010 or more.
  • I like the quality, dimension, stability, and performance of the Snyder's Venturi. They consistently have an optimal opening at the narrow point of .845" to .847".
  • Original Double Venturi assemblies were pinned into the castings. These pins need to be pressed out to extract the Venturi.
  • A Venturi can be difficult to remove from castings. Heating the castings in an oven or with a torch often loosens them up. Also, see Venturi Extraction Tool.

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