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post #1 of 12 (permalink) Old 11-17-2018, 09:40 AM Thread Starter
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post #2 of 12 (permalink) Old 11-17-2018, 09:57 AM
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The Street Demon 1901 625 CFM 4 Barrel Carburetor, Polymer Main Body is a copy of the Carter ThermoQuad. It is the carb that replaced the AVS and was the last carb that carter ever developed before switching over to TBI EFI systems that most sell as conversion kits for carbs.

Edelbrock tried to buy the rights to it when they bought the rights to Carter's AFB and the AVS carburetor line but Mopar was still using the ThermoQuad on their truck line. The original Edlebrock carb was a rebranded AFB (Aluminum Float Body), which GM branded as obsolete in the 1966 in their ads promoting their new QuadraJet. The AFB is a square bore (all bores are the same size) carburetor.

The newer Performer Series of Edelberock carbs is an AVS (Automatic Venturi Secondary) which Carter used to replace their older AFB line. The AVS is like a Rochester QuadraJet (that Carter made for Rochester before they built new plants to handle the increased demand for the QuadraJet when GM put them on every car they made). It uses the shape of the rear door and the throttle body to create a virtual venturi that changes the cfm rating depending upon how it is used. Unlike a QuadraJet the bores remain square instead of the big and little bores of a Quadrajet allowing it to be used on a square bore manifold

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post #3 of 12 (permalink) Old 11-17-2018, 11:13 AM Thread Starter
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Which would be most ideal for the 283 in your opinion... want crisp throttle response and good idle.
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post #4 of 12 (permalink) Old 11-17-2018, 11:48 AM
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Quote:
Originally Posted by Darkoverlift View Post
Which would be most ideal for the 283 in your opinion... want crisp throttle response and good idle.
Rochester QuadraJet off of a 305 would be your best choice. A second choice would be a 390 cfm Holley for throttle responce to a 600 cfm for performance (and iy is your cheapest choice0>

https://www.summitracing.com/oh/part...rese1-_-holley

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post #5 of 12 (permalink) Old 11-17-2018, 02:05 PM Thread Starter
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The street dominator is cheaper. At 282...any opinion on it?
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post #6 of 12 (permalink) Old 11-17-2018, 02:47 PM
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ThermoQuad was great carburetor for Chrysler. Installed on top of 340, 360, 383 and 440 engines.

Big Dave
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post #7 of 12 (permalink) Old 11-17-2018, 06:41 PM Thread Starter
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Is the comment it was great for Chrysler a round about way of saying for the 283 you would be better off with edlebrock. Lol
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post #8 of 12 (permalink) Old 11-17-2018, 07:13 PM
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No Not at all. I used to run Carter AFB's on my 409 and 331 SBC builds back in the early sixties. I hated multiple carburation because you ran them out of necessity not a desire to look cool. It was the only way to get the cfm I needed for a high reving 409.

Dual carbs where such a head ache that the local Rolls Royce jag-You-war dealer brought me customer's cars to tune because the Weber carbs the customers had installed needed to be synchronized and tuned (after I first disassembled to even veryify they were all the same carb) A Weber is so modular that you have no idea what it is until you disassemble it and look at the parts inside. They also had me tuning up MG's (SU carbs) and Triumph V8's (Strombergs) after a while: until I put a stop to it.

I know a bit about carbs and they all do one thing, no matter the brand, or design, and that is to mix 12.5:1 parts air to fuel (ideal or 'Stoichiometric' is 14.7:1 but things go bad if you tune it to that ratio). Every carb made (of the same size as expressed in cfm) will make exactly the same amount of power as the next carb to be tested of the same cfm. Brands don't make power!

There is one reason (well two actually) that I use Holley carburetors (OK three reasons, as one is that I have been playing with Holley carbs for so long that I have boxes of used carbs for parts). The first reason is the reason that I left Carter and dual carbs. I can get one big Holley to do the mixing of air and fuel without having to synchonize linkage or tune each carb separately which cuts my expense and tuning time in half. Holley introduced the 1050 cfm Dominator to NASCAR Racing back in 1965.

The second reason is why almost all races use Holley carbs. They used to fall apart with a screw driver (they use a nut driver now) allowing you to tune the motor in the pits to match the weather and track conditions (changes in gearing). As with the Weber they are modular in design; which allows tuning almost everything (with a Weber or a BG King Demon you can as even the cfm rating can change in the pits wit a change of venturi).

You can tune a Carter as well, but there are only three big chunks and handful of small (easy to loose) springs rods and jets. Also you have to stick your paws into the carb body to change a jet and my paws are big. Tuning of a Carter is not as bad as on a Rochester (even I won't tune one and send them to certified experts to get one rebuilt and tuned for a specified motor). But once tuned they work great for a 100,000 miles (or a cam change, head change, etc.). Because a Carter isn't as easy to tune there are more running under the hoods of street cars than Holleys.

This is because I have purchased large roll around chests of tools tuning a Holley carb drug into my shop after an "Expert"; a friend who claims he knows what he is doing tuned it for them. Usually they are too large of a carb in the first place for the application and have mechanical secondaries which work well on light Camaro or Nova car with a manual gear transmissions, but not on a heavy Impala with an automaic and no rear gear to speak of.

I convince them of this by rebuilding a used carb from my box of parts and installing a smaller cfm vacuum secondary carb in it's place and tell them to go for a test drive. I swap them a 600 cfm 4160 for their 850 DP 4150 (plus labor) and we are both happy.

Big Dave
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post #9 of 12 (permalink) Old 11-18-2018, 09:39 AM
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Dave,

" The original Edlebrock carb was a rebranded AFB (Aluminum Float Body),..."

Interesting. I thought the 'afb' stood for 'aluminum four barrel'. Now I'm curious about what 'wcfb' is. Do you know?

Pete
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post #10 of 12 (permalink) Old 11-19-2018, 11:08 AM
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Check out new Summit Racing brand carburetor. It's based on Holley 4010 and made by Holley for Summit.
The “guy” who designed the 4010 also helped design the Summit carb, making improvements on the shortcomings of the 4010.

IMO great carb for street driven cars, easily tunable.

I'm running 500cfm on my stock 327.
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post #11 of 12 (permalink) Old 11-20-2018, 10:26 PM Thread Starter
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Cleaned up the 1403 edlebrock on it...not a rebuild just took off and carb cleaner and exterior cleanup... hopefully it is a little better till I decide on a replacement. To many options. As soon as I choose I find a bad review...
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post #12 of 12 (permalink) Old 11-24-2018, 06:06 PM Thread Starter
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Ordered the steet demon in polished... won't get for awhile but went that route. Also went with the matching air cleaner assembly...
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