MTFCA Forum

I bought one a few months ago from my friend Bill which was already restored and was really too nice to mess with. So intrigued was I with the one Bill sold me, that I then purchased this one, was a very sad thing with every screw corroded to nothingness and the venturi totally falling apart as they often are.

None of the fasteners can be purchased (that I could determine with lots of research), so were all fabricated as was the venturi. The best thing is that now I have specialized tooling and mechanical drawings of all of the bits that go missing or get dorked up. After looking at this, I realize now that the fuel line is not installed for the picture, but it was fabricated as well.

I'm suspicious that this was NOS despite being filthy as almost all of the original lacquer (?) is there protecting the bronze, which I discovered after the initial cleaning, and I chose to keep for this one. Additionally, the throttle had zero wear and the float and needle looked pristine (good stuff is still out there!). For whatever reason, the center of the casting directly below the idle circuit vent screen had lost it's coating, and that surface represents what it would look like if it had gotten "the works". Perhaps the next one will get the Full Monty as they really look sharp that way. I think this one will patinate very well naturally.

I think this turned out well. I just wish I had a good camera as this doesn't do it justice...

What brand it it? It does not fit a standard T manifold. When were they made and what cars were they made for?
Norm

It's a Zenith S4BF, made specifically for "T"s. They came with a special manifold which I would have pictured, but it is out getting powdercoated.

Real beauty. Are they known for performing well on a T? How would you compare to other known carbs?

They were specifically made to make a stock "T" get up and go...and they do. They have a true idle circuit which is fully adjustable for mixture richness, as well as an acceleration well for instant "OOMPH" on demand. The only (minor) drawback is that they are tuned to a specific displacement engine via the selectible venturi and main and compensating jets. Any work done to the engine today may knock the factory settings out a bit, so you can make an adjustable main jet to compensate for that and it really helps dial in the carb to a massaged engine without having to experiment with different numbered jets (though that will work fine, too). I did not add an adjustable jet to this one but will on the next one.

Scott_Conger wrote: ↑

Tue Sep 28, 2021 4:19 pm

They were specifically made to make a stock "T" get up and go...and they do. They have a true idle circuit as well as an acceleration well for instant "OOMPH". The only (minor) drawback is that they are tuned to a specific displacement engine via the selectible venturi and main and compensating jets. Any work done to the engine today may knock the factory settings out a bit, so you can make an adjustable main jet to compensate for that and it really helps dial in the carb to a massaged engine. I did not add an adjustable jet to this one but will on the next one.

Excellent, adjustable main jet option.
Have that on an A type iron zenith fitz all carb. Works well.

I have two of those with manifolds. One was rebuilt by Stan Howe and the other is untouched. Have not put either one on a car yet. Might use one on the 11 open run about and maybe the other on a 14 touring.

Thank you for the information. It looks and sounds like a very good one.
Norm

I’ve found several over the years, most had a shattered Venturi. Stan Howe made a bunch of venturis for them. I sold a NOS one years ago for a pretty penny.

http://www.mtfca.com/discus/messages/33 ... 1381924692