Another carburetor identification question

[1crosscut]

I have a carburetor that a gent wants me to clean up for him. It came off of his 29 pickup. I'm not familiar with this one. It is a Zenith though.
I got all of the jets to come out except the main jet. The screw head of the jet sheared off almost immediately when I put pressure on it to take it out. Getting the rest of it out may be a challenge.
Is the main jet on this carburetor the same as the standard Zenith carbs?

[darrylkmc]

Model B, actually post '32 production as the float is '33 and later. Generally work well on Model A engine.

Darryl in Fairbanks

[Ron in Quincy]

The Carb is a 33-34 Zenith B.

The main Jet that screws into the carb from the bottom is the same as A.

There are two comp. jet , both are in the lower bowl , the larger comp jet is a #18 (.036), also in the lower bowl is a baffle, that is why they changed the float type.

To get the advantage of this carb the A manifold needs to be machined larger at the mounting as the throat is larger than a A carb.

If this carb will be run on an A you do not need the additional spring and plate on the float pin as it is there because the 32-33-and 34 have a fuel pump and its not needed with the gravity feed of the A.

Ron

[RUNNERBUN]

After drilling out of what is left of the broken main jet you may have to chase the thread. If so you will need to use a 5mm 75 pitch tap

[Charlie Stephens]

When you install this carburetor on a Model A manifold you will find it to be at a slight angle. The Model A suppliers have a bolt with a step that will correct this situation. Either that or you can start grinding.

Charlie Stephens

[darrylkmc]

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Originally Posted by Charlie Stephens

When you install this carburetor on a Model A manifold you will find it to be at a slight angle. The Model A suppliers have a bolt with a step that will correct this situation. Either that or you can start grinding.

Charlie Stephens

Actually it is the Model B Intake Manifold that causes the alignment issue instead of the carb. B manifold hole locations are angled as B's use a choke cable in lieu of the rod.

Darryl in Fairbanks

[Tom Wesenberg]

Originally Posted by RUNNERBUN

After drilling out of what is left of the broken main jet you may have to chase the thread. If so you will need to use a 5mm 75 pitch tap

I got very lucky one time with a broken jet in the carb. I bought a set of left hand drill bits, then used my variable speed drill on slow speed to drill down a little and let the bit bite into the brass. It then spun it right out. Or, should I say left out.

[Big hammer]

When working on iron carburetors if you would soak them in Evaporust before trying to remove hardware, jet, etc, you will find that frozen parts will come out very easy :-)
That is what I have found, I believe Evaporust works like penetrating oil !
Yes I love Evaporust, it will not harm solid metals ! And I don't work for them or get any kind of pay from them.

[Joe K]

Electrolytic methods work well at "undoing" rust too.

Rust occupies about 1.5X the space that the parent metal does - hence things "rust together" rather than "rusting apart." (That comes later.)

Electrolytic undoes this and eases disassembly. And does not affect copper base alloys.

Vince Falter does it with a carbon electrode - which I thought was a nice touch and removes any wire brushing clean up requirement after treatment.

http://www.fordgarage.com/pages/elec...cderusting.htm

I will take slight issue with some of Vince's statements. The problem with electrolytic methods is it leaves a surface which is "optimal" to recombine with oxygen. Use of a carbon electrode does not change this. And one of the reasons one should follow up electrolytic methods with SOMETHING. Either phosphate wash, quick glass bead, certainly a quick prime coat - ANYTHING to change that optimal chemical pre-conditioning for oxidation that electrolytic methods leave.

Still, as usual, Vince does a nice job and the clean up aspect of carbon is undisputed.

People wonder why I don't clean my hands after doing parts prep?

The answer is - I DID - and it didn't help. Something about organic tissue and Ferrous Oxide - Fe3O4 (black rust.)

Joe K

[1crosscut]

Thanks to everyone for the information and advice. Always nice to lean something each and everyday.

[Bob C]

Vince has a lot of information on his web site about that carburetor. Go to the link and scroll down to carburetors. Pay attention to the part about the Power Jet Tube, some times they are missing.
http://www.fordgarage.com/

Bob