Zenith carburetor identification

[David31dlxslant]

Has anybody ever seen a raised zenith without any #'s following the word Zenith? This carburetor is all original, the upper half is missing unfortunately. In the Judging standards is does not list a raised letter "zenith" without the 2, I've got several carburetors and am in the process of restoring all 17 variations in the judging standards but need some info on this carburetor if anybody knows anything about it.

[johnbuckley]

New one on me. Is there a secondary well? Are the main and cap jets in line or off-set?
Any name on inside of bowl?

[Rowdy]

I do not have any info on it, but I beleive I have in my parts stash somewhere. Will look next time I go out to the farm. Rod

[David31dlxslant]

Originally Posted by johnbuckley

New one on me. Is there a secondary well? Are the main and cap jets in line or off-set?
Any name on inside of bowl?

It has a replaceable secondary well as most of them do unlike the double venturi carburetors, which in turn it does have the offset cap and main jets like the single venturi carburetors. I have run into some holley carburetors with holley stamped on the inside of the bowl but thats usually on the raised zenith 2's. This bowl looks like a holley bowl by the casting, holleys usually had a little rougher casting than the zeniths is the reason i say that. Another reason i say holley is bc it has a passage plug on the bottom of the housing by the main bolt that ive only ever seen on the holley carburetors.

[Ron in Quincy]

I have been rebuilding carburetors for over 30 years and do not recall ever seeing only a raised Zenith on the bowl; it is no doubt a Holley.

I recently had a Zenith-1 and the upper housing for the back side of the throttle shaft was cast solid like the Holley's ; after researching found this was a Zenith-1 that was built after 1932 as a replacement. Zenith got smart and changed there casting so they did not have to use a brass plug to close off the back side of the throttle shaft.

Ron

[David31dlxslant]

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This is the passage plug I was referring to

[David31dlxslant]

Another picture

[David31dlxslant]

I think this carburetor was made between the plain no name Holley while they were transitioning into the raised zenith 2's, any thoughts?

[Joe K]

Originally Posted by David31dlxslant

I think this carburetor was made between the plain no name Holley while they were transitioning into the raised zenith 2's, any thoughts?

It has credence. I was first (before the Holley thought) going to say it might be a carb built by Ford in the period directly AFTER the Model A era as a service replacement. (and before Tillotson took up that position) But by then Ford was pretty much all Zenith and the exterior appearance and the holley plug kind of rule that thought out.

Or possibly an Argentinian copy? There are absolutely PLAIN (no name) carbs that resemble Zeniths, are rough, and were made in Argentina.

Some of these Argentinian plain carbs have evidence of grind-off of SOMETHING that was cast on the bowl. Maybe this one that got away?

I wish Purdy were here.

Joe K

[David31dlxslant]

I will say this, by the judging standards the 28-29 carburetors had a replaceable GAV needle seat made of brass, the 30-31 carbs did not have the replaceable brass seat but instead the housing had a machined integral seat that was not replaceable and this carb has a replaceable seat like the 28-29 carbs so I'm thinking if this was a post production carb that it would be like the 30-31 carbs without the brass seat but to me seems like it was made in 28-29 since it has the replaceable seat but I could be wrong, it's just weird no one else has ever seen one, I've been buying and building these carbs for about 11 years and have never seen one either

[Joe K]

am in the process of restoring all 17 variations in the judging standards

The judging standards are good - VERY good in fact - but they don't know everything.

Likely an 18th Version as yet unidentified?

Your rationale on the seat seems spot on. Argentinian carbs have integral seats IIRC. (cheap)

Maybe this thought will send others out to look in their parts boxes?

Joe K

[Mike V. Florida]

This is from Jim Mason's old site,

"While not in the Judging standards another Zenith carb exists. It is an early carb with a marking of ZENITH in raised letters."

[Ron in Quincy]

I have, over the years, had Holley's that the bowl was ground smooth about where the raised Zenith appears on your bowl ? You may be correct that this bowl went thru and the Zenith was not ground off. You are also correct about the brass removable seat for the GAV only appears on 28-29 carburetors.

Ron

[dlshady]

Originally Posted by Mike V. Florida

This is from Jim Mason's old site,

"While not in the Judging standards another Zenith carb exists. It is an early carb with a marking of ZENITH in raised letters."

Dang, I rebuilt one of those for a friend of mine just a few month ago. Thought something looked a little unusual with it but I didn't bother to take the time to find out what. He'd have probably traded me for a different version since he just wanted one that worked properly.

[Joe K]

So was the one you worked on a single venturi or double venturi?

Joe K

[David31dlxslant]

ok wow thats cool, at least someone else has seen this carburetor before, its probably not as common as most but i think it belongs in the judging standards between the no name holley and the raised zenith 2. Thats a good looking carburetor Mike Florida posted but has the wrong top body if the lower body is made by holley. Now the question is should i restore this carburetor to add to my collection or leave it original for research?

[dlshady]

Originally Posted by Joe K

So was the one you worked on a single venturi or double venturi?

Joe K

It was a single venture, but that's all I remember about it. I'll give him a call today and see if he's still got it laying around.

[Joe K]

Originally Posted by dlshady

It was a single venture, but that's all I remember about it. I'll give him a call today and see if he's still got it laying around.

Your investigation should be "informational." Like find out what orifices it has in it/venturi diameter/internal wells & arrangement and others can compare it to what might be more "typical" in this carburetor (Ford/Zenith/Holley did change orifices/arrangements as they went along)

This adding to the existing "type studies" which for the other 17 carbs is pretty well documented.

It may be the earliest single venturi carb? And subsequently improved upon?

And a unique chance to add to the information base?

You may be doing the hobby a distinct service - thank you.

Joe K

[Ron in Quincy]

At the beginning of 1929, Ford assigned ZENITH-1 to the Zenith Company, ZENITH-2 to the Holley Company and when Ford started building carburetors ZENITH-3 was used by Ford.

I believe the purpose of this assignment by Ford was to return carburetors that had a problem to the proper company.

I suspect Holley may already have cast some bowls which were on hand in early 1929; there solution was to grind off the raised ZENITH; no doubt some of the bowls got used with out grinding, causing questions today about variations.

Ron

[Benson]

There are two versions of this carb with the drilled "Lower passage"

1. One with the passage drilled from the bowl side like pictured.

2. And the second one with the passage drilled from the opposite direction (So the plug comes up from the bottom in this photo).

Also:

I would say that maybe one or two in 50 carbs, that I have seen, have this feature.

But I have seen enough of these to have noticed that there are two versions.

3. I have seen many lower bowls with the "Zenith" ground off.

I was told this was because after 1931, that Zenith sold upper / lower castings to Wards, Sears, rebuilders and Western Auto as replacement parts and/ or complete carbs.

Ford demanded that the Zenith be ground off so that folks could not return these as Ford parts under warranty.

[johnbuckley]

Originally Posted by Joe K

Or possibly an Argentinian copy? There are absolutely PLAIN (no name) carbs that resemble Zeniths, are rough, and were made in Argentina. Joe K

Yes certainly were foreign variations - KC/Qualcast in UK, Japanese ones and Agentinian, and I'm sure there were others. Came across an Argentinian Zenith 2 last week that had all the vent holes of post June 1930 but with a brass GAV seat, and as you say a rough casting.

[Carb Guy]

It is possible that the mold did not get the "2" recessed in it, a production mistake.

[fiddlybits]

Maybe I'm missing something here but ....

Standards manual - Revised 2011 - Area 1 - page-13 - "ENGINE-Holey Carburetor Casting CHanges 1028-1931" - has only one entry for "ZENITH" in Raised Letters

-> December 1928 - Type 3.

[Richard Lorenz]

I have a raised "Zenith" and my friend also has one. His has the number 24 upside-down on the back side, and mine has 30 upside down. There is no lettering or number on the rim inside the bowl. The vent is 9/32 inch diameter. I am certain that it was built by Holley because of other characteristics.

I date it as being used in about October of 1928, following a short time when Holleys with no name on them (usually called Plain ones) were being produced.

[Joe K]

Originally Posted by Richard Lorenz

I have a raised "Zenith" and my friend also has one. His has the number 24 upside-down on the back side, and mine has 30 upside down. There is no lettering or number on the rim inside the bowl. The vent is 9/32 inch diameter. I am certain that it was built by Holley because of other characteristics.

I date it as being used in about October of 1928, following a short time when Holleys with no name on them (usually called Plain ones) were being produced.

Single or double venturi on those?

Joe K

[David31dlxslant]

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Maybe it's time I upgrade my judging standards, I have the 1997 revision and obviously they've done some updating that I'm unaware of, thanks for everyone's help

Hey fidleybits could you post a picture of that page you're referring to? Thanks

[Richard Lorenz]

The Holley-made "Zenith" that my friend and I have is a single venturi. The latest Judging Standard section on carburetors has quite a few errors in it.

[Steve Schmauch]

Hello--This carburetor was produced in late 1928 by Holley. Most were recalled and ground off, some have survived. I believe this labeling by Holley is what prompted Ford Motor Company to require all future carbs starting Jan 1 1929 to have Zenith-l bowl marking on Zenith carburetors and Zenith-2 bowl marking on Holley carburetors. If you would like more information on Zenith carb identification, please obtain recent issues of the Model A Ford club of America's bi-monthly publication The Restorer. Best regards, Steve Schmauch

[James G.]

According to Steve Pargeter book Restoration Guidelines version 7a, the brass secondary well along with the lower body marking ZENITH, the carb would be a Zenith built between July 1928 to early '29. Re.: page 34.

[Tom Wesenberg]

Originally Posted by James G.

According to Steve Pargeter book Restoration Guidelines version 7a, the brass secondary well along with the lower body marking ZENITH, the carb would be a Zenith built between July 1928 to early '29. Re.: page 34.

That's the only Model A carb book I have, and I think it's a good book to own.