I think I’m throwing the towel with the old 8007 Holley, and ready to pull the trigger on an Edelbrock Performer 1403. I can’t get this chunk of pot metal to lean out at steady small throttle openings while running on transition slot. And tune a good reliable A/F mixture at idle that isn’t pig rich or too lean for good in gear idle. Idle adjustment A/F adjustment acts like a switch with no fine adjustment; it is either rich or lean separated by the slightest turn of mixture screws. Compromise is a mixture that bounces between too rich and too lean with rpm running up and down a few hundred rpm.

I’m tired of basking in pig rich stink wafting up from the stern at stop lights, and while parking in garage.

I just want to get a review on this carburetor’s compatibility with low idle vacuum signal. Will this device be tunable to hold a constant A/F idle mixture to stabilize idle rpm where no vacuum operated gizmos intervene to upset mixture?

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Sounds like the idle bleed needs to be drilled to get the adjustability window to open up to work with your cam (the 600 cfm holley has a wider aperature and is more tolerant of intake impulses/lumpy idle, but it's a downer on mpg due to the throttle plate/venturi size).

When picking a Carter/Edelbrock you also will have to ask how you like to adjust your secondaries...If you get the 1400 series it's an AFB so the secondaries are linkage and counter weight, if you go for the 1800 series it's an AVS and is vacuum secondaries similar to the Holley method you have now (on demand/spring change). If you can't find one at a local swap meet/junkyard, Edelbrock Remans are better quality than the Holley versions so you might pinch a penny there, FYI.

-D.Idiot

What does AFB and AVS stand for?

I found AVS... Air Valve Secondary.

Sounds like the idle bleed needs to be drilled to get the adjustability window to open up to work with your cam

Here is the rub, I don’t know if any of the idle circuit has been modified in this carb. After reading several Holley carb tuning books regarding idle mixture tuning, I have become confused; stick a V shaped wire in here, drill this and expect to ruin the metering block. My present thinking is to start with a new unmolested carburetor that hopefully can play nice with this engine and drivetrain.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Aluminum Four Barrel, this was the upgrade from the old 16 lb WCFB that predated it. The air door on the secondaries is counterweighted and the throttle plates are progressive linkage.

The AVS is vaccuum secondaries.

Suggested reading is Dave Emmanuel's Carter Carburators for a good run down on each model. Carter is very plug and play, but there are some nuances to each model (my favorite being an uncle having to epoxy a dime to the counterweight on the AFB air door to get it's timing correct on his 383).

Starting from a new benchmark sounds like a good plan.

-D.Idiot

I futzed with the Edel 500 elec choke AFB in the V2 Valiant for about 1.5 yrs, and never could get it to "acceptable" for me. I recently bought a new 1403 and bolted it on. With minimal choke and idle mix adjustment, it runs quite well (acceptable). Mixtures are close under all conditions, although I need to drop the cruise mixture with a metering rod change, and maybe drop the secondary jets by one step. Christine pumped it once, turned key, then drove it last night for 25 miles and did not have any driveability issues.

BTW, with your cam and engine buildup, it will be very difficult to get rid of the smell at idle. You can probably reduce it with a good/new carb or port EFI.

I have tried the 1800 AVS series and that worked OK, but I am not sure the air secondary valve adjustability gets you to a better place than how the 1403 is set up from the factory. Thus, I bought the 1403 for this recent application.

Lou

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Home of Slant6-powered fun machines since 1988

No, they are not vacuum secondaries. They use a spring to adjust the tension on the air flap, the tighter the tension, the later the flap opens. This is in loo of the AFBs weighted air flapper. Where you add or remove weight to adjust when it opens. Both designs are based on air flow, not engine vacuum.

The AVS is very sensitive to float levels, and the electric choke is sensitive to outside air/engine temperatures. For example it is starting to cool off in the mornings and the choke is starting to remain on longer then necessary. Out of the box, you may need to check the float level.

Actually if you want to get very specific about it, the AVS and TQ are actuated by both air flow AND manifold vacuum in lieu of Holley's Venturi Vacuum actuated system....

You have to mechanically open the secondary throttle plates and allow the manifold vacuum to start the venturi operation, there is a small pushover point where airflow will overcome the manifold vaccuum and actuate the air valve.

OK, some don't like the word vacuum and I think they might be right. It's actually a pressure differential, not air flow or vacuum, it's just a matter of having less pressure below the air valve than above. The spring/counterweight simply adjusts (tunes) the point and/or rate at which the valve reacts to said pressure differential.

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1966 Coronet Deluxe

Great point about the float level, Kesteb.

Lou

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Home of Slant6-powered fun machines since 1988