help identify Carter BB-1 Carburetor

[harvest]

my brother and I cannot figure what this Carter carburetor is from, so figure I ask for help. thinking is from the 1930's?  its marked BB-1 and also 750.  possibly anyone might know what this is for?  thank you for any knowledge that can be shared. 

[sagefinds]

That carb is from late 30's GM cabover trucks.  It could possibly be the best updraft carb ever made and lots of them are used on brass-era cars because of their dependability.  There are some variations of it that some claim are better than others but it's probably still worth between $75 and $125 as it is.

[30DodgePanel]

5 hours ago, harvest said:

my brother and I cannot figure what this Carter carburetor is from, so figure I ask for help. thinking is from the 1930's?  its marked BB-1 and also 750.  possibly anyone might know what this is for?  thank you for any knowledge that can be shared. 

 

 

Refer to this photo and notice the brass tag that I've highlighted with a yellow arrow. If you gently straighten and clean with degreaser and old toothbrush then post a new photo of the tag or tell us the numbers on the tag we can identify it further and more precisely. Many different types of vehicles this was made for depending on the numbers on the tag. 

 

 

Edited July 18, 2019 by 30DodgePanel (see edit history)

[carbking]

Guessing 1949~1953 Chevrolet 235 CID.

 

With respect to 30DodgePanel, DO NOT STRAIGHTEN THE RETAINER IN THE PICTURE, IT IS NOT A TAG. The bend is necessary to provide tension for the dust seal.

 

The tags on these carburetors were a rectangular tag (yours is missing) with two attaching holes. The tag would be just behind the choke cable bracket, with the two choke cable bracket retaining screws also retaining the tag. See the tag location on the first page of the factory service instructions:

 

http://www.thecarburetorshop.com/Service_Carter_BB_updraft.pdf

 

Jon.

Edited July 18, 2019 by carbking (see edit history)

[harvest]

appreciate the responses we got with this. at least were on track thinking its a GM/Chevy carburetor. I will look for some more numbers on this carb and will not bend the tab!   Thank you again. 

[30DodgePanel]

3 hours ago, carbking said:

Guessing 1949~1953 Chevrolet 235 CID.

 

With respect to 30DodgePanel, DO NOT STRAIGHTEN THE RETAINER IN THE PICTURE, IT IS NOT A TAG. The bend is necessary to provide tension for the dust seal.

 

The tags on these carburetors were a rectangular tag (yours is missing) with two attaching holes. The tag would be just behind the choke cable bracket, with the two choke cable bracket retaining screws also retaining the tag. See the tag location on the first page of the factory service instructions:

 

http://www.thecarburetorshop.com/Service_Carter_BB_updraft.pdf

 

Jon.

 

Thank you for your correction on the tag Jon.... my mistake. 

[carbking]

3 hours ago, harvest said:

appreciate the responses we got with this. at least were on track thinking its a GM/Chevy carburetor. I will look for some more numbers on this carb and will not bend the tab!   Thank you again. 

 

There are no additional useful numbers without disassembly of the carburetor. Then one can determine the main jet and idle jets, and then start eliminating until one one carb is left.

 

The only external number of value is the tag, which is missing in the picture.

 

Jon.

[30DodgePanel]

14 hours ago, carbking said:

The only external number of value is the tag, which is missing in the picture.

 

Jon.

 

Obviously the tag I "thought" I was seeing in original photo.... (need to get my eyes checked AGAIN)

 

Jon, what is your theory on why so many tags are removed from carbs over the years? I realize there are many reasons, but what specifically would you say is the main reason? 

FYI, I wanted to get your thoughts on it not for debate purposes, but rather because of your extensive experience with carbs. 

Edited July 19, 2019 by 30DodgePanel (see edit history)

[keiser31]

2 minutes ago, 30DodgePanel said:

 

Obviously the tag I "thought" I was seeing in original photo.... (need to get my eyes checked AGAIN)

 

Jon, what is your theory on why so many tags are removed from carbs over the years? I realize there are many reasons, but what specifically would you say is the main reason? 

FYI, I wanted to get your thoughts on it not for debate purposes, but rather because of your extensive experience with carbs. 

I would bet that most lost/removed their tags during a rebuild.

[30DodgePanel]

Just now, keiser31 said:

I would bet that most lost/removed their tags during a rebuild.

 

I realize that would be one reason for sure. Although I have no idea why mechanics would leave off one of the most important details.
But then again if most were done by backyard mechanics I could see it.

[carbking]

The vast majority of tags are removed by the commercial carburetor "rebuilders" when a carburetor is "rebuilt".

 

Several original carburetors may be "grouped" together and assigned one part number by the rebuilder. The original tag is removed.

 

As an example, one of the better rebuilders used to group ALL 1969 and 1970 V-8 Pontiac Rochester Q-Jets INCLUDING THE RAM AIR VERSIONS together under one number. This included Pontiac 350, 400, 455, standard transmission, automatic transmission, HO engines, Ram Air engines, and air conditioned engines. Each unit would be calibrated to a calibration done by the rebuilder; and is virtually always too rich (better to burn too much fuel than to be sued for a lean engine failure). Each casting would be drilled (if necessary) and ALL vacuum ports installed (if necessary) for ALL of the engines covered.

 

In general, for a specific engine original calibration (example Pontiac 350):

 

(1) The carburetor for a vehicle with automatic and A.C. would have the richest calibration.

(2) A carburetor for a vehicle with automatic would have the next richest calibration.

(3) A carburetor for a vehicle with manual transmission would be calibrated leaner than (1) and (2) above.

 

In the example about the 1969, 1970 Pontiac, the calibration for ALL would be for a 455 automatic with air conditioning.

 

This practice started in the mid-1950's with the proliferation of everything; the FLAPS complained that they were having to stock too much inventory.

 

The same thing is true with commercial carburetor rebuilding kits. In the case of the rebuilding kits, the expensive components are the fuel valve (a.k.a. needle and seat), and the accelerator pump. The commercial kit manufacturers basically do a spread-sheet for ALL carburetors using a specific fuel valve and accelerator pump, then add enough gaskets, pin springs, clips, etc. to service any of the carburetors on this spreadsheet. Additionally, fuel valves of varying orifice size, as long as the physical shape and thread fit, may be interchanged. And Carter and Rochester used different length accelerator pumps to control the accelerator pump shot volume, and these are often interchanged.

 

If you should buy a commercial kit - check how many carburetors it "fits". The carburetor interchange isn't quite as large, but still will often astound you.

 

EDIT: just thought I would mention, in my opinion, the second most common reason is the enthusiast/vendor. When did you last see a Rochester 2 barrel without a tag advertised on Ebay that was NOT a tripower carburetor?😠 When we were still doing swap meets, out of every 100 dual quad and tripower factory intakes, about THREE would have correct carburetors. Of course, none of them would have tags.

 

Jon.

Edited July 19, 2019 by carbking (see edit history)

[30DodgePanel]

So if I'm reading in to what you are saying,  commercial rebuilders removed the tags because they had no use for them essentially?

[Bloo]

5 minutes ago, carbking said:

Several original carburetors may be "grouped" together and assigned one part number by the rebuilder. The original tag is removed.

 

As an example, one of the better rebuilders used to group ALL 1969 and 1970 V-8 Pontiac Rochester Q-Jets INCLUDING THE RAM AIR VERSIONS together under one number. This included Pontiac 350, 400, 455, standard transmission, automatic transmission, HO engines, Ram Air engines, and air conditioned engines. Each unit would be calibrated to a calibration done by the rebuilder; and is virtually always too rich (better to burn too much fuel than to be sued for a lean engine failure). Each casting would be drilled (if necessary) and ALL vacuum ports installed (if necessary) for ALL of the engines covered.

 

^^^THIS!!!

 

This is why you should NEVER buy one of those over the counter "exchange" rebuilds, period, and if you do, you should NEVER turn in an original carb for a core. Carbking didn't even mention that you often find bent or broken critical parts inside when you tear them down. Or, that they sandblast the parts, removing the coating that seals up any porosity that might occur in the castings.

 

Carbs that have been through this process are generally not rebuildable as things have been drilled that cannot easily be put back even if you KNOW what size all the little holes are supposed to be, and generally you do not know. There are a lot of calibrated orifices in something like a Quadrajet! When the dust settles, it leaves the owner or the technician combing junkyards for a better core to rebuild. Meanwhile, the original carburetor is no longer around, having been sent in for a core.

 

Back when there were professional carb shops everywhere, they would not even attempt to rebuild something that had been through the "remanufacturing" process, and with good reason. When I was young and stubborn, I wasted a lot of time trying to do exactly that. I didn't have much success.

 

As for the tags, sometimes they just break off, or someone doesn't bother to put it back on when they put in a carb kit. That is a much easier situation to deal with. Sometimes the carb can be identified by other features, or if it it the original one, the make, model, and year can suffice. It still may leave you guessing on a setting or two.