Model A & B

Ford Garage

Aftermarket Cast Iron Intake Manifolds

The following pics show a couple of original era aftermarket cast iron intake manifolds for Model A & B Fords. The first is a Simmons Swan intake which is an updraft along the lines of a Model A, but with a slightly larger bore, and a higher turbulence balance tube. It was originally claimed that this would provide more even charge loading.

The second manifold shown is a Bendix Stromberg downdraft, though this particular one is not marked. I have another near identical one which has the name cast in.

Simmons Swan. This is a heavy manifold. Note the carb throat transition from round to square. Also has original style vacuum port for wiper. Original Zenith carburetors fit this manifold.

Original Model A style hotspot and exhaust mounting. Large size square runners.

The vertical tube is 1-1/4 inch ID compared to original Model A size of 1-3/16 and original Model B size of 1-5/16 inch ID.

Pictured above is a Bendix Stromberg downdraft. The vertical tube is 1-7/16 inch ID compared to original Model A size of 1-1/4 and original Model B size of 1-5/16 inch ID. It also uses a larger 2-11/16 inch bolt pattern to fit the Stromberg DCX2. The studs are 3/8 inch diameter. This has an original style vacuum port for wiper.

This pic shows the hard turns and also the through-boss for the throttle linkage bellcrank. Original Model A style hotspot and exhaust mounting also.

This is perhaps the most interesting feature. Both runners have a factory drilled 3/64 inch bleed hole at the bottom of the casting. Presumably to drain flooded gas. I wonder whether these holes stayed open or plugged up, and how it affected idle mixture over time?


More related information on Ford Garage:

  1. For more Model A & B related information, use the Site Search box at the top or bottom of this page.
  2. Model A & B Intake Manifold and Carburetor Mounting Flange Variations
  3. Model A & B Simmons Cast Iron Intake Manifold
  4. Model A & B Stromberg Cast Iron Downdraft Intake Manifold
  5. Model A & B Thomas Dual Downdraft Intake Manifold
  6. Model A & B Cragar Downdraft Intake Manifold

January 2004