Edelbrock AVS2 Carb

http://www.edelbrock.com/automotive/mc/carburetors/avs2.shtml

So is Edelbrock acknowledging there past issues of off idle hesitation or flat spots with these new line of carbs


I miss my 1407/1411 SO MUCH

Except the 1407/1411 isn't an AVS design

It's an AFB design.

Of course if you don't know the difference it's easy to not get them to run right.

Thanx for the Air Valve Adjustable Secondary non explanation that has so little to do with off idle issues unless the door is so damn loose or the spring is broken

Anyways


I run my own Rebuilt Tweaked Factory 1971 Carter AVS that performs flawless


I also have installed a few current Edelbrock AVS series carbs on friends cars that had off idle issues flat spots that I had to change a few things that I was able to fix that are light years ahead of the Performer Series line that I threw everything at



Why would they update the current line of AVS Series Carbs already ?



650 CFM, MANUAL OR ELECTRIC CHOKE
(THE ULTIMATE PERFORMANCE CARBURETOR)
The AVS2 Series is the next generation in Edelbrock carburetors. The AVS2 features annular flow primary boosters with a new calibration for improved off idle and cruising performance. The annular flow booster design delivers improved fuel atomization to eliminate flat spots that may be encountered when the carburetor transitions from idle to full throttle.

Looking at the catalog I see the AVS2 in only 650cfm size.
The entire Thunder series is still being sold.

Who'd have thought...annular boosters on an AVS?

R.

And I have been running a 1407 since 88 with no issues.

As far as I know no one has whined about the Edelbrock AVS carbs having issues, just the 750 AFB clone, NOT any of the AVS clones.

Must be something different and the AVS2 is not a "cure" for the AFB as you stated it nor does it "fix" the 1407 as there is nothing wrong with it a tune can't address.

Finally, the "improvement" on the AVS2 appears to be annular discharge boosters. Want to explain how that affects idle? Or off idle? Not on the boosters there.

I have ran many CarterBrocks over the years. And in years past were often my 'go-to' carb. The basic design is sound and some models do work okay.

BUT, they have waited way too long to make any real updates to the line while some models in the line have had know issues for years. Virtually all of their competitors have been adding models and variations to their lines while the CarterBrocks languish. Then there's the difficulty finding tuning parts and the complexity of the tuning chart, etc, etc.

So while the CarterBrocks aren't necessarily bad carbs, there are simply better carbs out there. We'll see how these new ones work out, but I would be surprised if they out perform or even perform as well as some of their competitors.

Can you swap the booster into an older carb?

Best part is

AVS 1805 is $364.00


https://www.summitracing.com/parts/edl-1805/overview/

AVS 2 1905 is $310.00


https://www.summitracing.com/parts/edl-1905/overview/

Has anybody tried the AVS2 and if so did it solve the off idle stumble that seems to be common with the 1407.

I've heard you can take a new carter kit and convert them to new metering rods and such. But have yet to have anyone come out with a step by step on the process.

It would be nice if they offered the boosters seperately. I have a fairly new 800 AVS I'd like to put them on.

You cant retrofit the annular boosters. I asked the question recently right after they came out. My guess is they would flow less CFM than the old style boosters based on how physically large they are.

I have also seen in an Edelbrock page on the net that the newer carbs that were either AFB or AVS style as it may be both have an off idle part throttle system that is not the transfer slot. It actually has a small nozzle in the primary throttle bores that will pull fuel just past the transfer slot to help the transition from idle to part throttle. I was surprised to see it as I did not know any Eddy carbs had that system I guess its kinda like the 3 circuit Holley Dominator system.

The system reminded me of the Quadrajet that has a secondary pull over system as they have to holes in the secondary throats that pull fuel out of them as the air valve goes past the holes when it opens. They actually call it a secondary acell pump in some Quadrajet books.

But I wonder if your Eddy carb has this part throttle pull over system ? Ron

I'm so glad my 71 Bee came with a Holley from the factory!!!!
Ron

all of the OE (68-71) AVS's were lean in an attempt to conform with the discombobulated federal emission regs of the era. You can get an Eddy performer strip kit & use the shorter primary jets/2 step rods in those AVS's. Go a slight bit richer than what is in the AVS now & work from there. OE AVS strip kits are as rare as hens teeth & dont toss the rods/jets you take out of there.

Bummer on the 650 max.

the main issues I've had with edelbrocks is calibration. I don't understand the reasoning they've come up with here but I suspect they're catering to the small block chevy crowd. anyhow, once that has been overcome these carbs are very reliable. I think the real downside to them from an all out race standpoint vs holley is the internal fuel passages size. I run a pair of 600's on a ch28 intake and really like this system. tweaks to the carbs were minor but in the end the best intake system I've run on a 440. a friend has an 800 avs on a 427 chevy and that thing took some radical changes to straighten out, but the end results were surprisingly good. I think the 650avs2 I a good step forward for the smaller engines. it's all about the cruise mode. I've found any off idle transition issues to be more related to idle af/ratio and too large squirter.

I just purchased 2 500 Performer carbs for my 360 and Street Tunnel Ram. I see the AVS2 is listed in 500cfm and I inquired. But the release date and thus shipping date gets closer and then gets pushed out time and time again. I was told by a Summit tech the AVS2 500cfm carbs are not calibrated for dual quad apps like their Performer brethren (added $$ for me to calibrate down for dual quad apps.) I believe because chevy is the most popular and most sold the Edelbrock carbs are calibrated to work optimally on 350 and 454 builds. But in this day and age a small block is a 400plus cubes and a big block is 490 plus cubes.

That's a shame. Would be nice to have another tuning avenue on these carbs. Will they physically bolt in place, though? I don't mind a small loss in flow on the primary side (hello Qjet/TQ) to help efficiency....

from what I've seen the annular booster is dimensionally the same as non-annular; unlike holley. just swap the clusters.

They talk about it (800 AVS2) in there latest blog like it’s already available on Edelbrocks website

But But But - I don’t see it anywhere

Quotes

"We followed up this year with a new 800cfm AVS2 that provides optimum performance for high-horsepower applications on both small- and big-block engine applications."

"The Edelbrock AVS2 Series Carburetor is available in 500cfm, 650cfm, and now 800cfm for high-horsepower applications"

Tried calling Edelbrock yesterday - That went no where on the 800 AVS2

Classic manufacturer tech line story.

“Avs.....what?”

The 650 shows in stock at Summit though.

Actually I was wrong about the Eddy carb as its the secondary side that uses the extra fuel circuits. Looks like it works like the system many Quadrajets use. I said primary earlier but that was a different carb as when I looked at this again I saw I was wrong as its the secondary side that pulls this extra fuel as the air valve starts to open. Ron
https://www.manualslib.com/manual/42643/Edelbrock-Performer-Series-1403.html?page=7#manual

You cant swap the new boosters from the AVS2 version to the old standard 800. This was straight from Edelbrock when those were first released.

I have found that my 800 thunder likes to run with the same total fuel “flow” but likes to be rich on primary side and lean on secondary side. By the chart I should be able to lean the front and richen the rear to be more balanced. NOPE!