Technical What Carbs Became What...

I keep learning this, and then I'll forget it again, so I want to get it in one place so I can make it easier. What Carb brands turned into what newer carbs:

• Rochester (2G, 4G) (squarebore) became Quadrajet (spreadbore)

• Carter (called WCBF) became Edelbrock - (Called AFB) (squarebore) (but Carter made quadrajets for Rochester when they needed more production)

• Holley stayed Holley - squarebore

What did I mix up?

 

Holley was turned into many aftermarket brands due to privateer racing carb builders, too numerous to even recall.

 

Hmmmm.....

Rochester made 1 bbl carbs, then they made 2bbl carbs, then 4 bbl, first square bore then spread bore.

Carter also went through the same progression. They sold out to Weber? Federal Mogul? before Edelbrock bought the AFB design. (their spread bore was called the Thermoquad)

Holley also went through the same progression, their spreadbore was the 4165.

The subject is a lot more complicated than you think it is.

 

Yep. And you should know that there is a difference between the "Square" pattern (early WCFB's, early Rochester 4G's, and some others) and "Square Bores" (later versions of those and AFB's and Holley's).

I learned this the hard way.

 

Since you seem to be mostly interested in 4 bbl carbs, the 4 big companies at the time (Holley, Carter, Rochester, Stromberg) all started making them around the 1953 model year. They all used a small bolt pattern, like tubman hints at. Then around the 1957 model year, the "modern" 4bbl Holley and Rochester and Carter carbs appeared. Stromberg kind of dropped out of it by then. The spread bores came along in the mid 60s, and were standard equipment on many V8 engines by the mid 70s.

 

Or 1100 1bbl, 2100/2150 2bbl, 4100 square, 4300 spread Autolite/Motorcraft/Ford to Summit M2008 square.
Mike

 

Paging @carbking .... @carbking to a white courtesy phone please...

 

I don't mean to get overly technical or deep in the history. The intent is more to make it easier when reading articles or the forums when people interchangably refer to Edelbrock as AFB or Carter as WCBF, and then I may go 4 months and forget which one represents which. It's more of a surface level vernacular dictionary than a comprehensive guide.

 

WOW! Talk about a generalized question!

Start by reading this: https://www.thecarburetorshop.com/Four_barrel_mounting_flanges.htm It will help understand the flanges.

Now, will try to sort out the genealogy (with apologies for post 1965 genealogy):

Autolite (I confess to knowing little about Autolite carbs due to a general lack of documentation.)
Autolite - 1957 4100 introduced for use on Ford.
Autolite - 1967 4300 introduced (spread-bore)

Carter - 1952 WCFB (originally square-flange, over time 1955~1956) became "AFB flange style"
Carter -1957 AFB (most AFB flange, but some dual flanged with "Holley" flange). Total redesign of the AFB after buyout by Federal Mogul about 1985. (We were a Carter distributor at this time). Still called "Carter AFB" for maybe 1 or 2years, the redesign was rejected by those accustomed to Carter quality. Y'all can take this one from here.
Carter - 1966 AVS sold only to Chevrolet (test for low-emission engines), Chevrolet discontinued in 1967. Fast forward to 1968, and sold to Chrysler to help Chrysler with emission issues. Discontinued after 1971 as O.E. Carter aftermarket documentation suggested these were tried in late 1971 and 1972, but NOBODY wanted one, discontined mid-1972.
Carter - 1967 produced quadrajets for GM under license, continued into the late 1970's
Carter - 5 February 1969 thermoquad (TQ) released as 850 and 1000 CFM aftermarket race carburetors spread-bore. Detuned for street use in 1971 as an 800 CFM for trial use on Chrysler 340 CID. Continued through early 1980's as both 800 and 850 CFM. Some were restricted into smaller CFM rating as low as 520 CFM as well.

Holley - 1953 model 2140 introduced for use on Lincolns (square flange). Descendants include 4000 (Fords and Mercurys mid-1950's), and 2140-G (with governor) continued through late 1970's on some military and commercial trucks because of reliability (regardless of the prattle on the 'net). All were square flange.
Holley - 1957 model 4150 (Holley flange). I will leave the genealogy of Holley (3150, 4160, others) to those who know dates and models better than I.

Rochester - 1952 4G (square flange) on some GM vehicles. Transistioned to AFB flange in mid-1950's. Last O.E. application 1966.
Rochester - 1965 quadrajet (spread-bore) introduced on 396 Chevrolet. Continued through mid-1990's on some marine applications.

Stromberg - 1952 model AAAA (this followed Stromberg's naming convention which may be found on my website). Due to the awkwardness, AAAA was changed to 4A. Square flange carburetor used on some 1952~1954 Buicks. Experimental versions tested by a number of other car manufactures in 1954~1955, but rejected due to cost.

It is important to note that many of these did not become something else. The Carter WCFB and AFB overlapped. The Carter AFB, AVS, and TQ overlapped.

Holley 4150, 4160, 3150, 4165 overlapped.

Hopefully, the above will help with the OP's question.

Jon

 

Hey Jon ,
I have some Carter AVS from a 69 or 70 Mopar that I would like to redo for an application .
The original application I’m working on took 2 AFB’s,,,,,,will AVS carbs physically fit in place of the originals ?
I know that’s a silly question,,,,,but I figured it would be wise to ask first .
If they can fit,,,,I’ll PM you about your services .

This is not a restoration or anything like that,,,,it’s a performance Mopar application .
The original AFBs can be had,,,,,but it would be like taking a mortgage on my home ,,,lol .
You’ll understand when I tell you the application,,,,if you haven’t guessed already .

Tommy

 

And that doesn't include weber who also built Qjets

 

Holley makes a spread bore Q jet replacement carb. Pretty good carb.

Edelbrock does not make a carb they buy carbs with the Edelbrock moniker on them.

The AFB is an Carter carb originally that came on higher performance GM vehicles but they also managed to land on some MOPARS. Carter also made the Thermo-quad carbs for MOPAR higher performance single carb motors.

 

As 4 barrels go from my personal experience the 52-53 Carter WCFB’s were supposed to be pretty primitive as they were there at the beginning. They as Jon said a square bore “small base” that stayed a year beyond the bigger bolt pattern introduced on the 55 GM engines. Other than the base gaskets, which both were included in ohaul kits, remained pretty much the same until the end. They lasted into the mid 60’s possibly longer and were easy to tune to me. I have a matching set (1953’s) on my early Ford dual quad manifold and the are perfect and have been trouble free for 6-7 years.
The first Rochester 4GC I had was an excellent driving carb on a stock engine (SBC) and if I remember right was a replacement carb to Cadillac dealerships where the customer had trouble with the early Carters. I remember seeing a 57-8 Cadillac 4GC that had larger back barrels and may have been the fore runner to the spread bore which showed up in 66.
I know EFI is everywhere today and the HAMB group of guys are what left using carburetors.

 

Most of the AVS units had the dual flange drilling ("AFB" and "Holley"); the ones with the smaller pattern would bolt up instead of the AFB's.

Remember the AVS was sold EXCLUSIVELY as a smog emissions carburetor. Any performance was just coincidental. Most buyers that were independently wealthy of new performance Chrysler products equipped with these removed them about 9 nanoseconds after exiting the dealer lot! Those that were not independently wealthy waited until the warranty expired, and then replaced them with either AFB's or Holleys.

These were sold as 630 CFM and 750 CFM (all throttle plates 1 11/16).

Yes, I understand about costs, and yes, dual quad hemi carbs should be platinum plated. However, because so many of these were trash-canned when new, a few years ago, there was a tremendous market of restorers trying to get the original carburetor, and remove the Holley. The 440 carbs brought as much OR MORE than hemi carbs! The 340 carbs almost as much (don't call, sold out of these for almost a decade!). The 383 units at one time were in less demand, and were good for parts to restore the 340, and 440 carbs.

Yes, I know this is a hot rod forum, and any good hot rodder can make a Dominator work well on a Sears lawn mower (if you don't believe this, just ask one ). Before deciding to do this project, check the second line in my signature block!!! Can help you with parts, but the only advice would be DON'T!

Functional replacement hemi dual quads may be fashioned from Carter AFB 4759s (yes, the arm is Chevrolet), about all that is necessary is rods and jets. Also, the original air cleaner will not fit (either the 4759s or the AVS units). If yours are 440, you should easily be able to trade one of them to a restorer for two of the 4759s (and if the date code is correct for his/her car, probably draw boot).

Jon.

 

Not just the H.A.M.B. folks. The kit business is busier than ever; which is what prevents me from working on carbs. Lots of folks still have carbs on their daily driver. We average a 216/235/261 six-cylinder Chevy kit per week!

Jon

 

I always thought Thermoquads were Rochesters. I learned something today. Thanks Jim, I'm not dead yet.

 

Coming from the classic aircooled VW scene our group are still very much into carbs on our cars, but we don't use the same ones the classic hot rod guys do. Mostly stock type Solex or Weber, or their reproductions. My daily driver for the last seven years (non-HAMB, I suppose) is a 1973 VW Super beetle with a pair of Weber 40 IDFs, and before that it was a pair of Solex 40/44EIS "Kadron" carbs.

I'm fairly certain that outside of the hot rod guys, the go-kart and VW scenes are the primary buyers of new carbs these days in the US.

EFI is something the average VW guy almost immediately disregards unless its in a state with emissions testing that requires stock setup or appearance. It's a shame because it's actually pretty nice on lots of the aircooled VWs, but expensive to source parts, and poorly understood.

 

I was watching "Engine Masters" on the MotorTrend Channel the other day, and the guys made the remark that they can make more power with carburetors than with fuel injection. At first glance, these guys (Freiburger and Dulcich) seem to be a couple of clowns, but after watching a few episodes, it is apparent they they really do know what they are doing. I respect their opinion.

 

I have a hard time seeing how this is possible. All carbs require a pressure differential to function. That means there must be a partial vacuum in the intake to work. That costs horsepower since EFI can function perfectly well with no vacuum (i.e., manifold pressure equals atmospherc pressure.) Add to that the fact that EFI injection may be timed to inject fuel at precisely the optimum moment.
Will someone explain to me how carbs can make more power?
Make no mistake - I love working on carbs and tinkering with them to best suit my needs, without the need for a laptop computer or a degree in electronics. But more power than a refined EFI unit... nada. Nope.

 

Thanks @carbking!

 

I believe for the most part Dave is referring to the bolt on “carb” appearing efi’s that are selling today. They do quite a few “test and tune” runs on each combo TV shown before you see the final one which is the best for the engine they have on the dyno. I believe it’s a pretty fair test for the most part.
When they do a single plane manifold test for an “out of the box” comparison it’s pretty accurate also with the disclaimer that when they use a Wilson modified or a Dart the numbers are always higher…..along with the price…. your street “Summit” buyer most likely won’t spend.

 

See, you put a qualifier in there....."refined". Might be that an engine that has been set up to work well with a carb just doesn't work as well when you add EFI. An engine that's been set up to work with EFI might do better than if you slap a carb on it.

I'm fine with running EFI in modern junk that came with it. But on an old engine, putting the right carb(s) on it is just so easy and effective, that I won't even consider wasting my time trying to get electronic stuff to work.

 

Ya know, pop your hood and show 1 or 2 dominators. That's middle finger, isn't it? Most impressive carb I ever worked with. Everything was huge and easy, but of course all I cared about was WFO. But who can ever forget or cast off the good ol Holley 3bbl? They're odd, like a tatoo you wish you didn't have right? But they worked and worked well from reports of old guys who had em.

 

All my hot rods and race cars use carburetors in some form or another. That is what I grew up on and that is what I like to tinker with. Just like I'd prefer to play with electric trains instead of RC monster trucks. Its my era.

But after spending years working with the Dearborn Dynamometer Laboratory I have yet to see an engine that didn't run markedly better after being converted to a "refined" EFI system. And by "markedly better" I mean making more power too. Not some aftermarket generic one-size-fitzall, but an engine that had been rigorously dyno mapped.
EDIT: I should clarify that I am talking about a multi-port EFI system with individual injectors for each cylinder. Centralized fuel injection systems that simply replace a carb with electronic injectors have their own bag of snakes to deal with.

I know I can buy an aftermarket EFI and sit in my driveway with a laptop and adjust the tables until I'm crosseyed. But I'll stick with carbs and all their idiosyncracies and enjoy myself doing it.

 

Stromberg [UK & USA] became Sherryberg [China] probably without Stromberg's permission

 

Don't forget my favorite Holley 3160!

 

Just a small addendum to Carbking's top notch description of four barrel carburetors; the 1953 Lincoln Holley is the only "teapot " style carb I know of that had mechanical secondaries.

 

I had a 450 CFM Holley/Weber carb on a 283 back in the 80's. It worked well. Was it a 3160?

Gary

 

WCFB...Will Carter Four Barrel or some say White Cast Four Barrel.......AFB,,, Aluminum Four Barrel....

 

Nope! The 3160 is this legend!


Before there was the Dominator series (4500), these were 950cfm and 1050cfm monsters!