Zenith sidebowl carburetor

[HalcyonDays]

I have a late model 1931 Closed Cab Pickup with an indented firewall. The pickup currently has a inline(modern) filter and a Tillotson carburetor. The pickup is running rough and for a winter project I decided to swap out the Tillotson carburetor for a Zenith sidebowl carburetor and eliminate the inline filter as well.

I purchased a used/non-rebuilt carburetor which looks to be complete. Previous owner appears to have soaked the carburetor in some kind of oil and it came apart quite easily. I have read a few threads on rebuilding carburetor which have left me with a few questions: 1.) I do not have access to a bead blaster or any other type of blaster. Is this really necessary to do? Can I try to do by hand or should I take it to a shop that can bead blast for me? 2.) Carburetor Kits should I buy one from popular suppliers or is there a preference to buy from Renner's Corner with their flow tested kits? 3.) The GAV moves in and out fine but does not twist. I have not removed that yet, does this indicate any type of problem that I should be aware of prior to taking apart. Any help/thoughts would be great.

[johnbuckley]

1) soaking it in thinners and is often sufficient to clean things adequately , but blasting is better as it will ensure that there is no crud left in the carb. after blasting resoak in thinners and give it a good blow job with airline to rid of all grit.
2) flow tested jets are better as some of the non-flow tested jets are outside the rcommended range .
3) The GAV must thread onto the GAV housing to work properly.. maybe you need to push the GAV in more whilst turning to engage the threads. if no success then remove the GAV housing to see what's happenings in there... also if you bast it you'll need to remove the GAV housing anyway to get things clean and grit free.

[1crosscut]

I'm sort of on the other side of the fence when it comes to sandblasting carburetors. I don't like the idea of blasting sand into the passages. You can get a 1 gallon can/kit from most any auto parts store specifically for soaking and cleaning carburetors. It works really well for getting carburetors super clean. If you have rust inside the bowl etc... just use a small wire brush to clean it out. Soak it overnight, wash it good with water and Simple Green then blow out the passages with compressed air.
The carburetor cleaner comes in handy for cleaning other miscellaneous parts and pieces such as greasy nuts and bolts etc... too.

[AL in NY]

I'm with 1crosscut, don't bead blast the carburetor unless you plan on removing all the brass plugs to thoroughly clean out the passages.

[CWPASADENA]

Originally Posted by 1crosscut

I'm sort of on the other side of the fence when it comes to sandblasting carburetors. I don't like the idea of blasting sand into the passages. You can get a 1 gallon can/kit from most any auto parts store specifically for soaking and cleaning carburetors. It works really well for getting carburetors super clean. If you have rust inside the bowl etc... just use a small wire brush to clean it out. Soak it overnight, wash it good with water and Simple Green then blow out the passages with compressed air.
The carburetor cleaner comes in handy for cleaning other miscellaneous parts and pieces such as greasy nuts and bolts etc... too.

I also agree with not bead blasting carburetors.

I would use carburetor cleaner and then if there is rust, either inside or out, I would use Rust 911. This stuff works great for removing rust from inside passages as well as outside the castings.

My opinion,

Chris W.

[Tom Wesenberg]

Sponsored Links (Register now to hide all advertisements)

I've sandblasted carbs with good results.

Dollar Tree oven cleaner is the same stuff as the old hot tanks, and it does a good job.

[HalcyonDays]

Thank you to everyone that responded to my questions, the answers were a great help. I did end up soaking the carburetor in the gal can of chemicals and the results were very good. (Interesting point: the less expensive Wal-Mart brand worked better in this case than the more expensive NAPA brand.) I also ended up purchasing new "flow tested" jets from Renner's Corner, not sure I full understand the significance.

One additional observation. There was an article in the Restorer magazine that documented the various differences in the zenith carburetors over the years. It spoke of a foundry that made the carburetors identified by the letter "G". It went on to say that this foundry stop making or marking their carburetors before the sidebowl carburetor was introduced and no sidebowl carburetor would have the "G" markings. It further said that the Zenith "1" markings in the side bowl carburetors changed to Zenith "I" .

I do understand that the parts on the carburetors are interchangeable and that a lot can happen over 80 years. But.. in light of the recent questioning about "fact checking". How possible would it be for there to be an exception to this finding?

The reason as you may have guessed is that my carburetor is a side bowl, that looks to have been together for a long time does have the "G" markings and has the "1" not the "I" after the word Zenith.

Your thoughts?

[F.M.]

Originally Posted by HalcyonDays

Thank you to everyone that responded to my questions, the answers were a great help. I did end up soaking the carburetor in the gal can of chemicals and the results were very good. (Interesting point: the less expensive Wal-Mart brand worked better in this case than the more expensive NAPA brand.) I also ended up purchasing new "flow tested" jets from Renner's Corner, not sure I full understand the significance.

One additional observation. There was an article in the Restorer magazine that documented the various differences in the zenith carburetors over the years. It spoke of a foundry that made the carburetors identified by the letter "G". It went on to say that this foundry stop making or marking their carburetors before the sidebowl carburetor was introduced and no sidebowl carburetor would have the "G" markings. It further said that the Zenith "1" markings in the side bowl carburetors changed to Zenith "I" .

I do understand that the parts on the carburetors are interchangeable and that a lot can happen over 80 years. But.. in light of the recent questioning about "fact checking". How possible would it be for there to be an exception to this finding?

The reason as you may have guessed is that my carburetor is a side bowl, that looks to have been together for a long time does have the "G" markings and has the "1" not the "I" after the word Zenith.

Your thoughts?

I have several "JUST" the bowl section that have the "G" marking on it..

[figment]

The judging and restoration standards have a lot of the details that you are looking for . There are details on each of the many different cast iron carbs such as Zenith , Ford and Holley . Norm

[denniskliesen]

Keep in mind the RG & JS is their standards if you are having your car judged. You are free to ask the committee members if there are exceptions and that is what I would suggest you do if you are restoring your car to be judged.

[HalcyonDays]

Thanks again for all the replies here are before and after photos. Just need to wait until spring to install on Model A and test run.