The Stovebolt Site Forums The Shop Area Engine Shop Selecting a different carburetor

Seems like every week or so, there is another thread about a stovebolter wanting a different carburetor. So decided to start a new thread that would cover my recommendations for the Chevrolet 216, 235, and 261 engines.

Before I start, for those who are looking for the cheapest paperweight with a fuel inlet, read no further as this thread is not for you. I believe in quality, and doing the job ONCE ONLY. As an illustration to this, my shop truck (a 450 HP 390 CID non-stovebolt with two 625 CFM Carter AFB's running solid linkage), a brand that is the same as the last name of an older country music singer from Tennessee, gets 22 MPG at 70 MPH, and the carburetors, while somewhat fuel stained from todays fuel, have been untouched since installation 21 years ago. I don't have time to do things over, and I detest low efficiency.

So, caviat over, allow me to proceed.

I will give my quality rating to each brand/type of carburetor on a scale of 1 (awful) to 10 (wonderful). Others might assign different values, but these are mine. It is important to note that I am talking about carburetor types. Not all carburetors of any type are good for the same engine. Here, the enthusiast needs to do his/her homework.

I have previously posted usage charts for the Carter W-1, and YF on these forums - search.

Chevrolet 216:

Carter, Stromberg, and Zenith ALL made bolt-on aftermarket carburetors for the 216 of all years, some with manual chokes, some with automatic chokes.

Carter W-1 (those produced in 1939 and 1940 - 8
Carter W-1 (those produced from 1941~1948) - 8.5 (the 1949 would be an 8.5 except for the availability of parts, which relegates it to a 6).
Carter YF (those burning real gasoline) - 9
Carter YF (those trying to burn ethanol diluted fuel) - 8
Stromberg BXO, BXV, BXUV - 9
Zenith 28, 228 - 9

Chevrolet 235

Carter YF (those burning real gasoline) - 9
Carter YF (those trying to burn ethanol diluted fuel) - 8
Stromberg AFTERMARKET REPLACEMENT UNIVERSAL BXO, BXV, BXUV - 9
Zenith AFTERMARKET REPLACEMENT UNIVERSAL 28, 228 - 9

Chevrolet 261

Carter made no direct replacement carb for the 261, the YF from the late 60's 250 works well - 8/9
Stromberg AFTERMARKET REPLACEMENT UNIVERSAL BXO, BXV, BXUV - 9
Zenith AFTERMARKET REPLACEMENT UNIVERSAL 28, 228 - 9

All of the above would be for single carb application, and are the ONLY carbs I would personally recommend (again, others will have different opinions)

What would I personally use if I had a stovebolt?

To start with, all carburetors with automatic chokes would automatically be eliminated from consideration!

216 - Carter W-1 (1932-1936 569s, 1937-1940 420s, 1941-and newer 483s, 574s, or 684s) - I make the parts for the 684s, so it fits for me, but not recommended for others.

235 - Lazy answer Carter YF, Stromberg BX series, Zenith 228 series (this would be a stop-gap until the real answer below could be fitted).
235 - Real answer three sidedraft type YH carbs, running solid linkage, and modify the engine compartment to fit

261 - Lazy answer Stromberg BX series, Zenith 228 series (this would be a stop-gap until the real answer below could be fitted).
261 - Real answer three sidedraft type YH carbs, running solid linkage, and modify the engine compartment to fit.

Now, on doing one's homework:

The 216 uses an S.A.E. size 2 flange (2 11/16 inch center-center mounting bolt distance). The equivalent Stromberg model would end in 2 (e.g. BXV-2). The equivalent Zenith model would end in 10 (e.g. 228AV-10.

Both the 235 and 261 use S.A.E. size 3 flange (2 15/16 inch center-center bolt distance). The equivalent Stromberg model would end in 3 (e.g. BXV-3). The equivalent Zenith model could end in 11 or 12 (e.g. 228AV-11, 228BV-12). The difference between the Zenith A and B refers to the orientation of the choke shaft to the throttle shaft.

The Carter and Stromberg carburetor come in different venturii sizes with CAST-IN venturii. In other words, the venturii may not be removed and changed. If you want a different venturi size, start with a different carburetor. The Zenith carbs come with removable venturii. ADVICE: unless you are a carburetor guru, DON'T change the venturi, start with a different carburetor.

Carter, Stromberg, and Zenith ALL published books (some easier to find than others) that post the venturi diameter for a specific tag number. If a list of only tag numbers and venturii sizes exists, I have yet to see it; and while, if I wanted to dedicate several months to the project, I could publish one, I won't!!!!!

The idea is to first determine which brand you wish to use, then pick one with the correct mounting flange, and then pick one with the correctly sized internal venturi. The Rochester documentation is nowhere nearly so complete as Carter, Stromberg, or Zenith; so you may have to first disassemble the Rochester to measure the internal venturi diameter.

Identification of the carburetors

While clean non-tagged Rochesters make good doorstops, Carter, Stromberg, and Zenith can generally be identified.

Carter W-1 (tagged) but if the tag is missing, try this link: http://www.thecarburetorshop.com/CarterChevroletW1.htm

Carter YF carburetors (virtually all) have the identification number (3 or 4 digits, followed by the letter S) STAMPED (NOT a raised number) into the float bowl (center section).

Stromberg carburetors (virtually all of the above listed models) will have the number STAMPED looking straight down on the bowl cover, just above the fuel inlet.

Zenith carburetors use a riveted round tag. Most rebuilders are too lazy to use a hammer and chisel to remove the tag.

I will attempt to answer GENERAL questions about the above. General questions do not include "What is the venturi size on a Zenith 11147?", or similar. Questions such as that are for the reader to determine.

And yes, I am quite aware of other "carburetors", before you ask, go back to the top and read my second paragraph.

EDIT: while this list has been published elsewhere on these forums, adding the Chevrolet YF list to this thread to make it as comprehensive as possible: http://www.thecarburetorshop.com/Carter_YF_Chevrolet.htm

EDIT: Here is a complete listing of the Stromberg carbs sold exclusively for Chevrolet: http://www.thecarburetorshop.com/Stromberg_Chevrolet_carburetors.htm
The Stromberg list does NOT include general aftermarket universal replacement carbs. The number following the type on the Strombergs is the S.A.E. flange size.

Jon.

I hope this migrates to the Tech Tip area, perhaps after some questions have been asked and answered.

Very well put and helpful, Jon. Two comments I'd add:

1. I prefer automatic chokes and in my opinion Carter YF auto chokes work very well. Actually I think they're better at their job than I am.

2. Carter YF identification simply by the number stamped on the float bowl can lead a person down the wrong path. If the carburetor has no tag, it probably means it has been commercially rebuilt. And this may mean your air horn and float bowl are no longer anywhere close to being matched. I see these being sold on eBay constantly. Take a look at this one (which has been listed on eBay for about 2 years now): https://tinyurl.com/ups28yo The only part of that carburetor that I believe is a 3211s is the float bowl. Everything else is pure alphabet soup. There's another one listed as a 3211s which claims to have been taken off a running engine. The air horn for it isn't a 3211s either (if you look you can see the castings are different colors and if you look at the 3 NOS models I have listed, you'll see another interesting difference) and guess what...no tag. At least it is closer than the first one...but I wouldn't buy it.

Thanks. Useful for future reference.


It seems that way. I wonder how many carbs are unnecessarily replaced in an effort to cure poor running engines? Carl is fond of saying "it's never the carb". IOW, in many cases, the carb gets blamed for issues when it's likely something else such as ignition problems, exhaust blocked, overheating, internal engine issues, ...

So when should a carb be replaced? I would think in the following cases:
Existing carb is broken or worn beyond repair.
Engine modified in such a way that a different carb is required.

I know that this thread is for replacement carburetor’s, but I would be interested in Jon’s (carbking) rating on the Rochester B.

This will be interesting.

He will likely be too angry to answer in as professional of a manner as he is famous for.

I don’t want to create any controversy. I’m relatively new to this forum and I haven’t done much research on this subject or Jon’s past opinions. I feel as though I just stepped into a mousetrap and the spring is about to come down on me. If this subject is too controversial, I respectfully retract my request.

I bought one f those rebuilt rochester b fre rockauto and it is the best thing
since buttered toast. Has never run better.

I just read a few past posts from carbking and now know this opinion with good reason of Rochester B carburetors . I now know why my Rochester B is discoloring at the air horn gasket area. I definitely retract my request

Phil - I would give the Rochester B an 8, WHEN WORKING, but the reliability and documentation kicks it down to a no better than a 6. The ratings I assigned consider cost, performance, reliability, availability of parts, and available documentation. I alluded to this fact in the initial post about the Carter 684s (1949), which is a very good unit, but parts availability is terrible (not the carburetor's fault).

And for those that like the B, we are still giving one away when a customer puts in an order for three rebuilding kits with the same order. To date, even though we have sold three or more kits per order many times, we have been successful in giving away exactly.......................................................none!

The interesting thing, at least to me, is that the Rochester two barrel (1956 and newer, the 2G series) gets an 8.5, as does the square-bore Rochester four barrel (4G from 1955 to 1966), and the newer spread-bore four barrel (Q-Jet) I give a 9. Not a lot of carbs that I give a 9 or better.

And Gord&Fran, you have touched on an issue that is absolutely true. I actually talk about as many customers out of buying a carb or kit from us as sales. When one listens to the customer, one often finds that the customer just needs a little guidance. For many years now, I have stated (tongue in cheek ) that the older updraft carburetors were much more reliable than the newer downdraft carburetors. WHY? Because it was so difficult to get to the updraft, that the enthusiast/mechanic did more testing, and found the real problem before throwing rocks at the carburetor.

Jon.

Thanks Jon, I appreciate your candor. I had a similar experience when I first got my ‘52 and was troubleshooting why I couldn’t get it to run for more that a few seconds. I was convinced it was starving for gas, installed a rebuild kit and proceeded to take that Rochester apart four times before I replaced the condenser which was the real issue. And now, after reading threads about the issue of a warped air horn to body joint, I suspect my ‘52 is suffering from that fate too. That however is a subject I have no intention of discussing in the thread!

We need a tech article sticky from CarbKing!
This much valuable info can't be lost due to a forum post that will eventually make its way down to page 100...

Some very useful information. Among the people I deal with I am considered to be the Old Guy with all the answers, that is in part from reading a lot of what is discussed on this forum. I second the Tech Tip link . Thanks for the info Jon.

There are two additional Carters that are at least worthy of mention, and those are the type WE and WA-1.

Those that are familiar with Carter will recognize that Carter used (for some reason unbeknown to me) a suffix number that is the S.A.E. flange size less one. Thus both the W-1 and WA-1 carburetors are a size 2 S.A.E.

The WA-1 rates a solid 9 on my 1-10 scale. This was Carter's high priced single barrel, used on Oldsmobiles, Pontiacs and Packards among others. The reason I did not mention it earlier is the size 2 flange size, but many of the WA-1 have the internal venturi size for the 235 or even a 261. One use of the WA-1 was the 257 CID Olds. So if one doesn't mind slotting the throttle body (I don't personally like this, but it is an option) so then the size two flange could be placed on the size 3 manifold.

The WE also rates a solid 9.

The other downside for me is the automatic choke. Age will eventually (not yet ) force me into a dogmatic transmission; but the day I can no longer pull a manual choke is the day I hire a chauffeur!

Both the WA-1 and WE do have the advantage of a leather (totally impervious to ethanol) accelerator pump, and of course, Carter's metering rod technology.

Anyone interested in these can look on my website for applications, but the late 40's-early 50's Pontiac six would be a good candidate for a 235, and the same period Olds would be a good candidate for a 261.

Carter offered a direct replacement (but auto choke) WE for the 216, tag number 730S.

Jon

Hello Mr. Carb King. What grade would you give a Stromberg Aeroquad A4?

Rusty - the Stromberg Aeroquad was the highest quality of any of the early passenger 4-barrels. They would have been on more vehicles, but their cost was significantly higher than the competition. Today's rating would be lower than it should be, as I think we are the only source for parts. Total rating, because of general parts availability would be a 7.

Which stovebolt are you going to place this carb on?

Jon

Jon in the past you and I have agreed the work done by Carter engineers ought to be accepted and followed. In other words, Carter designed certain carburetor models to work best on certain year ranges of the 235 and because of notable changes in the 235 a person's most sensible option with regard to Carter carburetors would be to find the model Carter had designed for the particular engine he or she owned. Has something caused you to move away from that idea?

Jon - no, not at all. The engineers had better test equipment and resources than ANY of us.

However, one has to temper that with the change in fuel, and the fact that some of the carbs specifically designed for Chevrolet are no longer readily available.

Also to be considered is that Carter did not specifically offer a carb for the 261. And some folks (me included) just detest automatic chokes (3211s) for the later 235's. Showing may age here, but I can remember when cars costing more than $10k (Rolls-Royce and Ferrari) both had both manual chokes and manual transmissions.

The reasons I mentioned the WE and WA-1 are basically: (A) both are still more readily available than the Carter 2100s/2101s for the 235, (B) the leather accelerator pump, and (C) Carter NEVER offered their best carburetors (cost) for replacement on Chevrolet.

Again, this thread is slanted toward quality. The WA-1 was probably at least the equal of the YF in 1950, when drivers did not have to contend with ethanol. Today, it is better because of the leather pump. The WA-1 was discontinued in the mid-1950's because of cost, the YF was cheaper to produce, and sell. So I try to keep an open mind on other possibilities than what was recommended in the early 1950's. And the WA-1's used by Olds and Pontiac, while not dirt-cheap, are certainly more affordable than 2100s/2101s. Pontiac folks are like Chevrolet folks in the realm of power. An owner with a worn 216 Chevy will think about a change to a 235/261 before rebuilding the 216. A Pontiac owner with a worn 1950 Pontiac will consider replacing with an 8 cylinder before rebuilding the 6. Thus, there is less demand for the Olds/Pontiac WA-1's (forget about the ones used on Packards ).

Jon

That's very good to hear, Jon. You and I have talked about ethanol and concerns about the accelerator diaphragm in the YF models. Over this past year I've come to wonder, however. The 3211s I'm using (which will go dry at least 6 or 7 times each year) hasn't given any trouble at all and just the other day I received a YF (which came from a known user). He believed the carburetor had never been rebuilt, had sat unused for years before he got it and he told me it had been used with ethanol laced gas since around 2008. All the gaskets were genuine Carter gaskets and I could not find any evidence to dispute what he told me. The diaphragm was still working. So possibly my initial concerns about deterioration of the diaphragm were overstated.

As for auto choke, you do know the old auto to manual choke conversion kits are still being sold, yes? They don't look to be the same quality as those made and sold in the 60s, but I imagine they would still work. For people who might have trouble sleeping if an automatic choke happened to be hiding in their garage...

I will tell you for the 1957 and newer 235s I've not found a better option for the money than the 3211s. Quick starting, smooth, very efficient and responsive. And no seeping, weeping and dribbling.

Carbs? Many of us might have regrets about things related to our trucks. My biggie was an estate auction I attended. This fellow had an at least 3'x3'x3' wooden box built on a shipping pallet. It was filled to the top with old carbs! I had to get to my daughter's event (can't remember which) and didn't stay for the carbs to come up for bidding.

I think there was a bunch of Stovebolt-good carbs in there.

There was another box on a pallet full of PTO's.

This was 25 years ago and I still cringe when I think about it. Daughter would have forgiven me by now.

Mr. Jon (Carbking), This morning I dug around in my stash of treasures bought at swap meets over the years and found two long forgotten carburetors. One is a Carter YF 787SB and the other is a Carter W-1 574S with the tag still attached. Both appear to be in fine condition for their age, although I would rebuild them before bolting them on for use. According to your original post, both are recommended by you, but my question is which one should I put my money, time, and effort into? I have a 1950 216 motor.

Thanks for sharing all your expertise with us!

If you have to burn ethanol diluted fuel, then the W-1 574s, without question.

If you have access to real gasoline, then which ever one seems to be in the best overall condition; unless you, or your mechanic has a preference.

If you do the W-1, read the article on my website about cleaning the idle circuit, and expanding the idle jet tube top.

Jon

There’s a brand new gas station being built just down the street that will sell real unleaded gasoline without ethanol. After my recent carburetor problems I have vowed to never put ethanol laced gasoline in my truck ever again. I’ll put a kit in the W-1 and see how it runs. Thanks Jon!

I intend on putting two of them on a Chrysler 354... what that goes in is still up in the air!

Thinking out-loud here.

Interesting comments about the WA-1. I’ve seen them on eBay and wondered if they could be made to work.

Pre-68 Dave had mentioned that he gets favorable results with a 216 manifold/carb on a 235. Perhaps a bit better throttle response and low end performance. Giving up a bit at higher RPM. I think that’s a fair paraphrase of what he’s said.

Rather than slot the WA-1 flange to fit, a guy could use the 216 manifold and have the best of both worlds. Benefits of the smaller runners at low rpm and have a properly sized venturii to not give up any top end.

This is all foreign language to me.
Sorry everyone, just haven't learned yet.
Do you have anything on carbs for the 51 GMC 228?
We got it with the Zenith 11147 carb on it.
Is it better to rebuild it or get something else?

The Zenith should be an excellent carb, assuming it is the proper version for your engine. I vote for rebuilding it.

Zenith 11147 IS the CORRECT carburetor for this application.

Another vote for rebuilding.

Jon

Thanks for resurrecting this thread -- Good Tech Tip material. Although ... Being on the search currently for the *correct* carb for my 261, I have a minimum of enthusiasm for encouraging competition ...

JohnM: PM sent.