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 Comparing Carter WCFB and AFB carburetors in the context of Air Cleaner HeightJump to page : 1 Now viewing page 1 [50 messages per page] | View previous thread :: View next thread |
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56D500boy |
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Exner Expert 10K+ Posts: 11182     Location: Lower Mainland BC | . I started thinking about this because of Frank W's 57 Super D500 with two Carter WCFB carbs sitting on a low profile/non-air gap Offenhauser style 2 x 4 bbl manifold and why the factory went with two "side-saddle" (oval element) air cleaners. In the middle of that, I had a conversation with Charlie L. and his desire to add an air-gap 2 x 4 bbl manifold (and carbs) to his 56 Dodge D500 (currently single 2443S WCFB). In the middle of that, I realized that by 1958 the factory had done away with the WCFBs and moved to Carter AFB (aluminum four barrels). I did NOT know the difference in the heights or the venturi sizes of these two styles of carburetor but I did know that by 1958 they were able to move away from the side-saddle 57-style air cleaners and move to what became more conventional large diameter paper element air cleaners without worrying too much (apparently) about the underside of the hood (bonnet for the Brits) hitting the top of the air cleaner. I will get to the air cleaners in a reply to this post but I will start with what I found out about the WCFB vs AFB differences. What I *think* I learned (subject to correction and/or confirmation by those on this forum with more knowledge/better resources) is the WCFBs are considerably taller than the AFBs. Measuring from the bottom of the carb base plate to the air horn ring where the air cleaner base sits I have measured (and confirmed with other sources), the height of the WCFBs are 4 5/8" high. In contrast, the AFBs are 3 1/4" high (base to air cleaner base ring). That is a significant 1 3/8" lower. That opened up some room under the hood right there. More room would be gained by going to non-air gap manifolds but I don't think I will go there (yet). The other things that I *think* I learned was the air horn diameter (diameter of where the air cleaner sits) is much smaller on a WCFB than a AFB. WCFB = 4.25" , AFB = 5.125". As a result, a "modern" air cleaner will not sit/fit on a WCFB without some kind of adapter (I have played with that one several times). Perhaps more importantly to all of these dimensions is the fact that while the WCFB primaries and secondaries have the same 1 7/16" diameter, the AFB went to two different diameters, 1 7/16" on the primary bores and 1 11/16" on the secondary bores. That, and the difference in mounting bolt spacing, 3.75" x 3 7/8" for the WCFB and 4.25" x5 5/8" for the AFB, means that *IF* you wanted to mount a AFB (or AVS) carburetor on a WCFB manifold (single 4 bbl or 2 x 4 bbl) manifold, you would need some kind of adapter. "Fortunately" (that might be debatable), adapter plates (and hardware) are available. One down side it the adapters are 1/2" thick - which might not be an issue considering that the AFBs are 1 3/8" less tall from the get go. A table to summarize the above and some photos for visual reference (Note the table is labeled "Rev 0" to allow for updates as new data rolls in from those more knowledgeable.  : (CarterWCFBvsCarterAFBdimensions_TableRev0.jpg) (Carter2443SD500CarbShowing4EqualSzedVenturis_1point4375in.jpg) (Carter2443SD500CarbShowingHeightToAirCleanerBase_4point625_Annotated.jpg) (ExampleAFB_AVS_SideView_ShowingHeight.jpg) (ExampleAFBBasePlate.jpg) (ExampleEdelbrockToCarterWCFBAdapterPlateKit.jpg) Attachments ----------------  CarterWCFBvsCarterAFBdimensions_TableRev0.jpg (73KB - 153 downloads) Carter2443SD500CarbShowing4EqualSzedVenturis_1point4375in.jpg (105KB - 195 downloads) Carter2443SD500CarbShowingHeightToAirCleanerBase_4point625_Annotated.jpg (190KB - 137 downloads) ExampleAFB_AVS_SideView_ShowingHeight.jpg (68KB - 150 downloads) ExampleAFBBasePlate.jpg (122KB - 171 downloads) ExampleEdelbrockToCarterWCFBAdapterPlateKit.jpg (40KB - 152 downloads) | ||
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| Powerflite |
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Exner Expert 10K+ Posts: 10542  Location: So. Cal | |||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | Powerflite - 2026-01-02 4:44 PM However, the horn inlet is the same diameter on both of them. The air horn on the AFB changed to the larger 5.125" size around 1965 or so. So all of the AFB's from '57-'64 have that small inlet on them, similar to the WCFB. Thanks Nathan. I guess that is why I had the ?? in Rev 0. Just found this: "Early Carter AFB carburetors had smaller air horn diameters, often around 4 1/2 inches (4.5"), fitting the initial square-bore design (circa 1957-1961), while later or larger-CFM versions, like those for performance big-blocks, transitioned to a larger 5 1/8 inches (5.125") diameter for increased airflow. You might find smaller, ~4.25" versions for Corvettes or specific applications, but 4.5" and 5.125" are the primary early/later sizes. " Previously, I said: "A table to summarize the above and some photos for visual reference (Note the table is labeled "Rev 0" to allow for updates as new data rolls in from those more knowledgeable." I revised the table accordingly (but I was over the 999 minute EDIT time limit so I couldn't swap out Rev 0 for Rev 1). Here is Rev 1:  Edited by 56D500boy 2026-01-03 2:22 PM (CarterWCFBvsCarterAFBdimensions_TableRev1.jpg) Attachments ---------------- CarterWCFBvsCarterAFBdimensions_TableRev1.jpg (50KB - 162 downloads) | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Based on what I *think* I know, all of the early 51-56 Chrysler products with Carter WCFB 4 bbl carburetors used oil bath air cleaners that were attached to the WCFB via a center stud and wing nut. These air cleaners tended to have relief depressions on the bottom to clear the choke housings and fuel lines and on the side to clear the Power Steering pumps attached to the back of the generators (on the left side of the engine). This is probably one of the first Dodges with a WCFB 4 bbl, the 1954 Dodge 500 Indy Pace car (carb sits on an Offenhauser aluminum intake made on contract to Dodge): Here is a 55 Dodge Lancer with a 4 bbl WCFB on a cast iron air gap manifold and oil bath air cleaner: One of the first 56 Dodge D500 engine bay photos that I collected, showing a Chrysler style oil bath air cleaner, sitting on a Carter WCFB, with a clearance depression for the PS pump (Vickers in this case) Here is what I think is a 56 Plymouth poly with a Power Pack WCFB 4 bbl and the same kind of oil bath air cleaner: Here is a 56 Plymouth Fury 303 with a WCFB 4 bbl and a gold version of the Chrysler 4 bbl oil bath air cleaner Same type of air cleaner on a WCFB showing the reliefs for the fuel line and choke: Another shot of the bottom of an early WCFB air cleaner showing the clearance reliefs, *AND* perhaps, more importantly, the seemingly restrictive 2" opening at the carburetor. (Makes no sense to me) This shows a 56 Dodge D500-1 2 x 4bbl intake manifold mounting two WCFBs And this is the resulting single air cleaner developed by Purolator for the 56 D500-1s: And on a 56 D500-1, showing a clearance dint at the back to clear the heater motor (not needed for Nascar applications with heater deletes): I *THINK* that covers the 54-56 WCFB era. Next up will be the 57-59 era, including the switch from WCFBs to AFBs in 1958. Edited by 56D500boy 2026-01-04 2:32 AM | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | 56D500boy - 2026-01-03 12:32 PM. Next up will be the 57-59 era, including the switch from WCFBs to AFBs in 1958. Things to "remember": 1. Some basic engine configurations carried over from 1956 to 1957, think: the 315 and 325 double rocker engines, same block, same (ish) heads. 2. Hood heights were lowered considerably in 1957 (and 58) compared to 1956 for both the Dodges and Plymouths As a result, for one example, the 1957 Dodge D500 engine with its single WCFB and air gap intake manifold (with separate valley cover) made the tall oil bath air cleaners from 1956 pretty much impossible. For example, this 1957 Dodge D500 carb and intake stand very tall: I guess there would have been a few options on the engineering table for discussion: 1. Can we make a shorter intake manifold without compromising performance? 2. Can we find a shorter carburetor that works on the air-gap intake? 3. Can we develop an air cleaner that works with the air-gap intake and the WCFB, at least in the short term? I am guessing that for Dodge, 1 and 2 were possible but 3 was easier and less costly, resulting in the "side saddle" air cleaner, as shown on this 1957 D500 (note: the 57 non-D500 4 bbl WCFB polys used a similar side saddle air cleaner but the filter element was round not oval like the 1957 D500 air cleaner) And then there was the 1957 "Super D500" which used two WCFBs on a somewhat lowered air-gap intake manifold: A 315/325 2 x 4 bbl manifold: That manifold still wasn't enough to avoid the side saddle air cleaners, as shown here on a 1957 Dodge Super D500: In the meantime, what has Plymouth been up to? Well for starters (no pun intended), their first V8s (the 1956 277 from the Mound Road plant - not the 1955 Dodge engine borrowed for the 1955 Plymouths), they went with a non-air gap intake (eliminating the need for a separate valley cover). Like this one for 1956 and 57 "Power Pak" 277 and 301 V8 Plymouths Here is a 57 Plymouth Belvedere 301 sporting that intake manifold with a WCFB and a huge side saddle/saddle bag air cleaner (similar to that shown on the 57 Dodge 4 bbl poly above) : By 1957, the Plymouth Fury 318 was sporting a non-air gap 2 x 4bbl manifold with two Carter WCFBs. However, even with the lower profile, non-air gap intake manifold, they still went with the side saddle/saddle bag air cleaners: That is enough for today. I will do what I can tomorrow with the AFB transition and the move away from those side saddle/ saddle bag air cleaners. . | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Contrary to what I said (thought I knew) above, not all Carter AFBs had 1 7/16" primaries and 1 11/16" secondaries. There were some AFBs that had both 1 7/16" primaries and 1 7/16" secondaries. Who knew? Well, I didn't  that is until I got an email with attachments from one of my 56 Dodge D500 contacts (Charlie L. in New Mexico). Charlie's photos clearly show a Carter 2787S AFB with four 1 7/16" butterflies. (See below). I was surprised. I did some digging and found out that in addition to the 2787S being used on some 57-64 Cadillacs, it was also used on some 1959 Dodge and 1959 Desoto Firesweeps (based on the 59 Dodge) with 361s, auto transmissions and the power pack (normal carb was a 2 bbl). With this correction, I will now move on to finding previously posted photos of low profile air cleaners on 58 and 59 Mopars with AFBs. (TOMORROW?) (Carter2787SAFB_Top.jpg) (Carter2787SAFB_BasePlateWithModelStamping.jpg) (Carter2787SAFB_Bottom_showingSameSizeButterflies.jpg) (1959CarterAFBInfo_1024.jpg) Attachments ---------------- Carter2787SAFB_Top.jpg (94KB - 129 downloads) Carter2787SAFB_BasePlateWithModelStamping.jpg (74KB - 121 downloads) Carter2787SAFB_Bottom_showingSameSizeButterflies.jpg (100KB - 154 downloads) 1959CarterAFBInfo_1024.jpg (185KB - 139 downloads) | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Well it is tomorrow already so I better finish this off. To be honest, I getting a bit bored with this (as I am sure you, the reader, are as well). As a result, *IF* I can't find appropriate, previously up-loaded to this forum, air cleaner photos, I am going to "borrow" them from Nick's Garage's excellent compilation of air cleaner info https://www.nicksgarage.com/aircleaner.htm Suffice it to say, once the shorter (less tall) Carter AFB carburetors were introduced fully in 1958, there was almost no need to continue on with side-saddle/saddle bag air cleaners as using in 1957. Instead, the air cleaners all sat upright on the AFB carburetors with paper filters. Single AFBs used big(ish) round air cleaners with snorkels, dual quad AFBs used the oval "football" air cleaners. One example, 58 Dodge with B block engine, probably with a square bore 2642S AFB:  Here is a 58 Plymouth 318 4 bbl with an oval mouth air cleaner: I don't think that oval mouth lasted more that a year because by 1959, 4 bbl Plymouth 318s were sporting a single round snorkel air cleaner like this one:  A bit later, the B block 361s in Golden Commando Plymouths sported a non-snorkel air cleaner:  In the meantime, the dual quad engines were sporting the twin oval/football air cleaners: I think that will be it (unless somebody has suggestions/finds errors). One thing that I did keep bumping into was other square bore AFBs besides the 2787S, e.g. the 2642S. There are probably more, if I go looking. But that is thread for another day (or week). Edited by 56D500boy 2026-01-09 11:01 PM | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Just a couple of things: Just picked up a used 2787S AFB and discovered that, although the butterflies are the same diameter as my 2443S WCFB (1 7/16"), the spacing of the early AFB butterflies is different that the WCFB. That would make an adapter plate for an AFB onto a WCFB intake manifold more manditory (than just to accommodate the mounting bolt spacings). That will negate any height advantages relative to the WCFB This is what I found out this afternoon: Edited by 56D500boy 2026-01-29 8:29 PM (WCFBbaseGasketOnWCFBToShowSizeAndAlignmentMatch.jpg) (WCFBbaseGasketOn2787SAFBtoShowDiameterMatch.jpg) (WCFBbaseGasketOn2787SAFBtoShowAlignmentDifferences.jpg) Attachments ---------------- WCFBbaseGasketOnWCFBToShowSizeAndAlignmentMatch.jpg (108KB - 143 downloads) WCFBbaseGasketOn2787SAFBtoShowDiameterMatch.jpg (154KB - 151 downloads) WCFBbaseGasketOn2787SAFBtoShowAlignmentDifferences.jpg (112KB - 170 downloads) | ||
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| Mopar1 |
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Expert Posts: 3185  Location: N.W. Fla. | |||
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| Powerflite |
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Exner Expert 10K+ Posts: 10542 Location: So. Cal | The photo you show for the '58 Dodge big block engine is completely wrong. This is what it should look like, essentially the same as the '58 DeSoto. These air cleaners work on both the 4bbl and 2bbl, as they came with the same opening during this time. If the car came with A/C, it used the side saddle air cleaner instead. Also, that's an odd looking 318 in your '58 Plymouth picture with the distributor in the front. That's the correct '58 Dodge big block picture. The '57-'58 Plymouth poly air cleaner was a mini version of the big block air cleaner. Edited by Powerflite 2026-01-30 8:12 PM (1958 Dodge-DeSoto BB Engine.jpg) Attachments ---------------- 1958 Dodge-DeSoto BB Engine.jpg (161KB - 207 downloads) | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Not sure where I got the Plymouth "318" photo. That said, it is obviously (now), that it is a B block, maybe 350 or 361. I mostly wanted to show the wide oval snorkel but yes, it is NOT a 318. One thousand lashes with a wet noodle work for you? | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . Picked up a used Carter 2787S AFB as would have been used on a 58 Dodge MD3-H (probably a 350 or 361)(??) Measured a couple of things: 1. The air cleaner mounting base circle has an outer diameter of 4.5" (same as the WCFB - the air cleaner gaskets fit each other) 2. The height of the AFB from the base to the top edge where the air cleaner would mount is NOT 3.25". It is 3 11/16". And although the butterfly diameters are the same as the WCFB at 1 7/16" the center to center spacing is different. Hmm.... Today's measurements (I see a Rev 2) in my future (DavesCarter2827SAFB_ShowingOuterDiameterOfAirCleanerMountCircle.jpg) (DavesCarter2827SAFB_ShowingHeightFromBaseToAirCleanerMount.jpg) Attachments ---------------- DavesCarter2827SAFB_ShowingOuterDiameterOfAirCleanerMountCircle.jpg (114KB - 172 downloads) DavesCarter2827SAFB_ShowingHeightFromBaseToAirCleanerMount.jpg (194KB - 124 downloads) | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . I found some 57 WCFB and 58 AFB Dodge intake manifolds on eBay today and thought that I might as well add the photos to this thread. Both the 57 and 58 manifolds have the choke well for installation of an external choke "driver" (e.g PN 1737 781). The 57 manifold is for a 325 hemi (D500) and shows what I have been calling the air gap runners. I thought that the 58 B block manifold would not be air gap but I guess they were still "air gap" (the Plymouth 318s would not be air gap). The 57 manifold is confusing me a bit because the carb mounting flange is drilled for both AFB and WCFB. While that might be possible, the spacing of the 1 7/16" butterflies is different for the WCFB and AFB, as shown above. The 58 manifold is definitely set up for an AFB carb. I've added a typical choke driver at the end as an example. (57D500Hemi4bblManifold1735774_NoteChokeWell.jpg) (57D500Hemi4bblManifold1735774_UnderSideToShowAirGapRunners.jpg) (58LowDeck350_361_AFB_Intake1737708ShowingChokeWell_Top.jpg) (58LowDeck350_361_AFB_Intake1737708_ShowingChokeWell_Detail.jpg) (58LowDeck350_361_AFB_Intake1737708ShowingChokeWell_Bottom.jpg) (57-58MoparChokeMechanism_1737780.jpg) Attachments ---------------- 57D500Hemi4bblManifold1735774_NoteChokeWell.jpg (242KB - 152 downloads) 57D500Hemi4bblManifold1735774_UnderSideToShowAirGapRunners.jpg (243KB - 189 downloads) 58LowDeck350_361_AFB_Intake1737708ShowingChokeWell_Top.jpg (151KB - 158 downloads) 58LowDeck350_361_AFB_Intake1737708_ShowingChokeWell_Detail.jpg (128KB - 139 downloads) 58LowDeck350_361_AFB_Intake1737708ShowingChokeWell_Bottom.jpg (114KB - 133 downloads) 57-58MoparChokeMechanism_1737780.jpg (206KB - 179 downloads) | ||
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| 56D500boy |
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Exner Expert 10K+ Posts: 11182 Location: Lower Mainland BC | . I was playing around with the 2787S AFB that I bought to potentially put on my 56 Dodge D500 yesterday and noticed that the intake manifold, PN 1634 262 (which was also the 56 315 poly power pak (4 bbl dual exhaust) intake) was also cast with the mounting pad extensions suitable for drilling and tapping for an AFB. So I presume the Dodge boys knew that the WCFBs were going to be replaced by the AFB soon(ish) but for some reason there was a delay. That said the AFB butterfly spacing is slightly different than the WCFB so the manifold would have to be modified in addition to the drilling and tapping to mount an AFB. Here is a bit of mine and then one from eBay showing the extended pad. Edited by 56D500boy 2026-02-10 7:37 PM (DaveFs1634262D500IntakeManifoldShowingPadExtensions_1024.jpg) (DaveFs1634262D500IntakeManifoldShowingPadExtensions_SideView_1024.jpg) (1634262_315_PowerPkg_Intake_1024.jpg) (1634262_315_PowerPkg_Intake_On56_315Poly.jpg) (1634262_315_PowerPkg_Intake_On56_315Poly_Detail.jpg) Attachments ---------------- DaveFs1634262D500IntakeManifoldShowingPadExtensions_1024.jpg (150KB - 115 downloads) DaveFs1634262D500IntakeManifoldShowingPadExtensions_SideView_1024.jpg (174KB - 172 downloads) 1634262_315_PowerPkg_Intake_1024.jpg (88KB - 92 downloads) 1634262_315_PowerPkg_Intake_On56_315Poly.jpg (126KB - 107 downloads) 1634262_315_PowerPkg_Intake_On56_315Poly_Detail.jpg (132KB - 152 downloads) | ||
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