The Stovebolt Site Forums The Shop Area Engine Shop Carter AVS carb

I just found an old Carter AVS carburetor, 4-Bbl, progressive linked,square-bore. Not too rusty,
Anybody have any experience with this device? What CFMs, usual applications, etc. Are parts still available?
Would it be suitable for a 292 L-6 w/Offy 4-Bbl intake. I'm looking for other options besides the 390 CFM Holley 4160 R-8007 that's still soldiering on after 24 years.
Thanks.

Those carbs were standard equipment on Mopar muslecars such as 340, 383, and 440 4bbl engines.They make a fairly decent performance carb.The one advantage the AVS has is the primary metering rods which makes part throttle jetting changes easy just like the AFB. The secondary air valve is also easy to adjust to tailor the opening rate to your engine.These carbs are somewhat similar to a Rochester Quadrajet, but the AVS's larger primary throttle bore gives a more powerfull response at part throttle openings and doesn't have a rich idle problem often found on Q-jets.The CFM rating is around 650 cfm.

Thanks Tony,
It sounds a little large for a 292, But I'll keep it handy in case I need one for a V-8.
Zipkits are still available?
Also is that vacuum can on the side a choke or part of the secondary system?

You called it "square bore". If by that you mean primary and secondary throttle bores are 1 11/16", then it's from a 440. If the primaries are 1 7/16" and 1 11/16" secondaries, then it's from a 383 or 340. If it has a single air bleed adjustment with left hand threads on the front center it's from a '68. If it has two mixture adj it's '69-71. If it has a idle vent valve on top of the air horn behind the throttle pump and operated by the same linkage, it's a '68-69. If the idle vent valve is internal on the pass side, with a control arm hanging out and a 3/8" vacuum tube (hanging down at a angle) for the vacuum canister, then it's '70-71. The vacuum unit on the left side front is the "vacuum brake" used to pull the choke open when you drive away without letting the engine warm up. If there is a similar unit behind it above the fuel line inlet, then the carb was on a manual trans car. This "dashpot" has no vacuum connection.

The only thing the AVS shares with a Quadrajet is the spring loaded "secondary air valve". You can adj this to open when ever you like. The AVS metering rods are lifted with low vacuum, whereas the Quad meter rods are connected to the secondary air valves and are lifted with high air flow. The popular edelbrock performer is a very, very, very cheap version of the AVS. The edelbrock has a counter weighted air valve that has to be replaced to adj (or drilled/welded to change its weight
The CFM rating is ?????
On the 440 version I have seen people say it's anywhere from 580 to 750, but they always agree the 383/340 is 100 CFM smaller. I think the small one is closer to 500.
Chevy used it in '67 on one version of the 327 and Chris-Craft with 307, 327 and 350.
I have had two different holleys and both size AVS on my 440. The Holleys gave more power, but the small AVS gave the best drivability around town.
I have a '70 1 7/16" I just rebuilt to go on a Clifford. I want to switch to a hanging gas peddle with cable before I put it on and havn't gotten around to it. I don't know if I'm too darn lazy or I just spend too much time lurking on this board.

Good info Richard, you must be a Mopar guy.
The Rochester Quadra jet has metering rods on both the primary and secondary side and as you noted the secondary ones are lifted by air valve movement.I believe the primary rod position is controlled by vacuum.
The AVS has metering rods on the primary side only. And if my memory is correct, they are without secondary venturi clusters ,similar to a Q-jets
The Edelbrock is almost identical to the older Carter AFB and comes in several cfm ratings-500-800.

I guess it is more of a spreadbore than I originally thought -- just not as radical as a Holley doublepumper. Primaries are 1" 7/16ths, secondaries 1" 11/16ths, more or less.
There is a spring actuated flap above the secondaries, that seems to be moved only by engine suction -- is that it or is something missing?
The Choke/vacuum brake is on the passenger side... there is a "3/8ths angled-down inlet forward of the fuel intake on the passenger side, too. and the carb has 2 separate mixture screws in front like an AFB.
I'm also working on putting in a '72-style accelerator pedal setup to use a cable instead of the pushrod/bellcrank rube goldberg rig that we had to fabricate 20-something years ago to operate a 390 cfm Holley in sidesaddle configuration. It's about to give out and doesn't give me WOT anyway. We had to fabricate a metal box to mount the gas pedal pivot to the '68 firewall. The bolt pattern is slightly different.
"SplitSix" over in the Inliners page ran the AVS numbers [K7 4966S] for me and came up with it being out of a '71 Mopar 440, with 750 cfm. Too big for my .030 or .060 -over 292, but it makes for an interesting discussion.
Thanks,
Brian