1928 Chrysler 72 Carburetor

[Syncros007]

I am trying to get my 1928 Chrysler Model 72, engine running. It is not completely restored yet; however last night I had it running for about 5 minutes. I had a couple of issues and maybe this is the way it is suppose to function because I think it is an automatic carburetor. I read in another post that these carburetors do not like E-10 gas, which I am using. I was going to post on his thread, but didn’t want to steal it going in a different direction. Can someone explain to me how a 1928 carburetor is supposed to work and function? The following is my procedure from last night:

1) When the choke is on, if I go to open it, it revs the engine up, and does not allow for me to open it wide.

2) Every time I mess with the accelerator (on right in picture), or what I am assuming is the accelerator, it cuts the engine off because the choke is closed.

3) So, I left the choke be for 5 minutes, let the engine warm up, and then tried simultaneously opening the choke and lifting the accelerator from the carburetor. This caused the engine to die and back fire.

4) Once the engine shut off, it started dumping a steady stream of gas out the bottom of the carburetor. I had the engine running by sitting a gas can on the ground and running a hose from the top of the vacuum canister to the gas can. So, I shut off the valve at the bottom of the vacuum canister and that eventually stopped the leak, but if I would have left that valve open, would it have dumped all the gas out that was being held in the vacuum canister?

5) Is this the way that style of carburetor is to operate? I am use to being able to control the choke and if you open it wide to soon, it shuts the engine off, not revs it up to a very high rpm. When the gas drained out of the bottom, did this mean it was getting flooded, or do I have another problem?

6) On the top of the vacuum canister, there is a line that passes through the firewall, but I do not have that connected, and not sure what it gets connected to or its function?

Any help is appreciated.

Thanks,

Kyle

[carbking]

Your carburetor definately is not original to the application. While impossible to positively identify from a picture, it is a Carter BB-1 updraft PROBABLY from a late 1930's Chevrolet truck.

The Carter BB-1 is an excellent carburetor IF IT IS CALIBRATED FOR YOUR APPLICATION!

The fact that you must run choke indicates that the carburetor is not providing sufficient fuel; but when using the choke you are preventing the carburetor from supplying sufficient air to allow wide open throttle.

Leaking fuel when the engine is not running is unfortunately very common with ALL updraft carburetors. It shouldn't, in a perfect world, but I would personally never trust one, and would always use the fuel shutoff.

Where do you go from here?

My suggestion would be initially to disassemble and rebuild the carburetor. That way you know this carburetor is doing the best it can. Will this solve your problem? I don't know, but is less expensive than rushing out and buying a new carburetor; and it may solve your problem.

Jon.

[Syncros007]

Jon,

Can you jump over and look at the thread for "1928 Chrysler 72 - Engine & Title Number", billnoon had posted pictures of his 1928, 72, and his carburetor looks similar. Looking similar obviously doesn't mean they are the same, but can you tell his type? Obviously I am no expert either, and I will check mine out tonight to see exactly what type it says. For all I know it could be off of something in the 1930's. I am just taking off with the restoration, where a gentleman left off and sold to me. I had sort of figured in the back of my mind, I was looking at rebuilding the carburetor, but I just wanted better advice before I dove in.

Thanks,

Kyle

[carbking]

Kyle - the pictured carburetor in the other thread is, like yours, a Carter BB-1.

I looked at both your picture again, and also the other picture in more detail. Both of these carburetor were produced AFTER 1949.

Carter produced dozens of different type BB-1 carburetors. These were produced for MANY different size engines, and thus carried different internal venturii, and different calibrations. As stated before, they are excellent carburetors.

The very FIRST Carter BB-1 was sold in 1931 on new 1932 models.

The early Carter BB-1 carburetors used 3 main body screws. In 1950, this was changed to 6 main body screws. Both your carburetor and the other one have 6 screws.

Jon.

[carbking]

A wee bit more information:

According to my records, the 1928 Chrysler mode 72 would have been equiped at the factory with one of three carburetors as follows:

Left hand drive - Penberthy model SV-37

Right hand drive (early) - Stromberg OX-2

Right hand drive (late) - Stromberg UX-2

The Stromberg model OX-2 is a bronze carburetor.

Both the Stromberg UX-2 and the Penberthy SV-37 were made from a very early form of "pot metal" (or white metal, or zinc alloy, or some other names which would be edited if posted here). This early zinc alloy had too much lead, and cracked badly. There are virtually no ORIGINAL examples of either of these left in the solar system.

As the Stromberg UX-2 has many applications, a gentleman in Australia has reproduced these, so new reproductions are available (again, these were used on R.H.D. cars).

Carter produced 3 different sizes of their type BB updraft carburetor IN A UNIVERSAL CONFIGURATION. The universal carbs can easily be distinguished from the O.E. versions by looking for the following features:

(A) a throttle shaft that extended on both sides of the throttle body (to allow linkage on either side) with a clamp-type lever

( an externally adjustable main metering jet

© a flat linkage rod running from the choke arm to the throttle arm (approximated a fast idle circuit).

The part numbers for these universal Carters:

(A) S.A.E. size 1 carb - early 245s (three screw), later 245sd (6 screw)

( S.A.E. size 2 carb - early BB1A, later BB1D

© S.A.E. size 3 carb - early 289s, later 289sd

Since the participants in the Great American Race really like the universal Carters (and they are legal for use in the GAR), prices have escalated to the ridiculous. Thus, many who either don't know or don't care have been offering the O.E. BB updraft carburetors for sale at lower prices for different applications. If the calibration is close, and the throttle can be attached, they work very well. However, if the calibration (both internal venturi size and jet (there are 4 in the BB updraft) sizes are not close, the O.E. carb may not work so well on a different application.

Jon.

Edited April 21, 2011 by carbking (see edit history)

[2251DB]

THE PROBLEM SOUNDS SIMILAR TO SOMETHING I EXPERIENCED WITH MY CAR,CAN YOU TRY

USING GRAVITY ONLY FOR YOUR FUEL SUPPLY WITHOUT THE VACUUM LINE TO SEE IF THERE

IS ANY DIFFERENCE IN ENGINE OPERATION

[1929Chrysler]

The other vacuum line extending through the fire wall should be connected to your windshield wiper which works off of vacuum.

[2251DB]

HAVE YOU BEEN ABLE TO GET YOUR CAR RUNNING

[lozrocks]

Check out the service procedures:

Carter BB - The Carburetor Doctor

[Syncros007]

I actually came across another problem, I have not yet pulled apart the carburetor, however last weekend I was running the engine for 20 minutes or so. I have the choke on because that is the only way it will run now, but other than it running rich due to the choke being on, the temperature was good as well as the oil pressure. No problems there. Then I started to hear what sounded like a knock to me, towards the front of the engine. I quickly turned the engine off, and smoke started to come out the cap where you fill the oil at. I opened that up, let the smoke come out, and saw a bunch of metal shavings. So, I took off the valve covers and saw metal shavings in there. Now I am dead in the water and not sure where to start. I just had replaced the oil pan gasket, so I know everything appeared in order and good inside.

[Syncros007]

lozrocks - that is exactly what I needed. The Carter BB Service Procedure for updraft is an exact step by step procedure for people like myself.

[Syncros007]

Also looking at that Carter BB Service Procedure for updraft, would the carburetor not be functioning properly because the choke linkage is not connected.

[lozrocks]

If the choke butterfly is closed then the engine won't be able to get air. I'd be trying to get the carburetor assembled correctly before you go too much further. But to get 20minutes of run time with the butterfly closed is very confusing. That suggests a lack of fuel or a hell of a lot of air getting through one of the gaskets.

You also said that fuel was pouring out of the bottom of the carburetor. I think there are two ways that this can happen. Firstly if the needle in the carb is not seated correctly the fuel flow will not be stopped. The more common reason is a faulty vacuum tank. The vacuum tank will continue to suck fuel through until the tank is full and then the vacuum will suck the fuel directly into the manifold flooding the carburetor.