Different Model A Venturi
 

..
Found this at a Swap Meet today.

Same as Zenith but with brass insert.

Does not look home made.

What is it for.

Thanks


..

Re: Different Model A Venturi
 

Looks like some sort of aftermarket venturi. Put it in a Zenith carburetor and see if it runs.

Re: Different Model A Venturi
 

since venturi is smaller maybe it is for a British engine ...

Although Henry would have used all pot metal unless there was a manufacturing problem which required brass for the smaller opening.

Brass was expensive

Re: Different Model A Venturi
 

If the inside diameter of the venturi is smaller it will restrict power .

Re: Different Model A Venturi
 

Added some pictures

Re: Different Model A Venturi
 

Any foreigh help on this

Re: Different Model A Venturi
 

Si, No es Ford!

Re: Different Model A Venturi
 

The carburetor for the AF engines did have a smaller orifice venturi (and smaller jet orifices as well).

Here is an original, April 1931, document from Zenith, France indicating the size of the AF single venturi. See the blue arrow indicating that the venturi of the carburetor for the AF engine is "18" compared to the venturi for an A and AA engine is "21.5" (look under the "Diff" column):
https://www.fordbarn.com/forum/attac...1&d=1569812928

"Diff" = Diffuseur, the french word for venturi

So based on the measurements that you show of your mystery venturi, it seems like it is not a venturi for a Model AF engine.

Brad in Maryland

Re: Different Model A Venturi
 

Thanks for posting that info Brad

Re: Different Model A Venturi
 

Yes I concur with Brad the smaller engine was 18mm dia venturi ( approx 0.7 inch). Suspect that the venturi in the OP is someone's experimentation.

Re: Different Model A Venturi
 

Good one Davey!

Re: Different Model A Venturi
 

Just found this one in a pile of carburetor parts.

Re: Different Model A Venturi
 

I wonder if it was an aftermarket accessory to improve fuel economy since it was around the time of the great depression???

Re: Different Model A Venturi
 

Might this be a part intended for use on an air compressor conversion running on two cylinders? Or maybe just a restrictor to improve economy on some sort of stationary power unit that would run constant rpm? From what I can tell, the Ford industrial engines used the standard Zenith but other engines in things like combines used unique carburetors. This might have been a bandaid to make the Zenith work better for those applications.

Re: Different Model A Venturi
 

I can visualize the "double your mileage" ad in the back of a 1930s Popular Mechanics magazine.

Re: Different Model A Venturi
 

I can picture that as well. On second thought though, it might actually increase fuel consumption over the stock venturi. Smaller opening would mean higher velocity at a given rpm, which would pull more fuel through the jets. Might help low end and throttle response though.

Re: Different Model A Venturi
 

I'm going to take a good running carb and install it, I've got to see what it does.

Re: Different Model A Venturi
 

Isn't that a model B venturi?

Re: Different Model A Venturi
 

Could be 1 of them JC Whitney catalog miracle mileage gadgets they seem to have plenty of those in the 60s and 70s!!!

Re: Different Model A Venturi
 

A friend here in Mathews just found a brass one sitting in his show case. Now I've seen two in less than a week.