I have been trying to get a feel for edelbrock carbs.

Seems the common complaints are:
1.) bowl capacity
2.) Flooding while cornering (float height according to edelbrock)

Other than that they seem to be a darn good carb for easy tuning, and every day reliability.

So I am building a 396 small block. I am thinking about a decent hyd roller.(its a roller block)

I can run a decent 288(236) single pattern camshaft, and rock and roll every day.

If I go with a single plane, I could use the 650cfm offroad carb which should solve alot of the problems as far as flooding and weirdness. But I am also wondering about bowl capacity for sustained high RPM usage. (4300-5800ish)

So if I moved up to the 800cfm carb, the bowls look pretty good size. But then I would want to use a dual plane intake.

I have a couple of single planes around, so I am inclined to the AVS thunder series off road carb.

 

Like most everything performance related, the secret is proper matching of components. Leaving aside the superiority of a properly set up Q-Jet for most purposes, the Edelbrock is an excellent carburetor.

Match the carb up to the right intake manifold for your purposes, with the proper jetting, etc., and it will perform at or above your expectations. Too many people have simply thrown a bunch of parts together, no matter how high their quality, and been disappointed at the results and blame the parts and manufacturers.

Edelbrock carbs are great for ease of tuning and not losing adjustments. Basically, you set them and that's where they stay.

Call or e-mail Edelbrock techs, give them what you have and plan to do, and see what they tell you is the best way to go.

 

Edels are Carters. I would ask lars what he thinks of them.

 

They "look" like a carter, but that's where it ends. There have been a lot of changes to them internally and some externally. To say they are exactly a carter would be wrong. That's like saying a demon is nothing but a holley. Lars favorite carburetor is no longer being produced by GM. All carburetors have their pluses and minuses. Holley has made good carbs and they have also produced some junk. So what is one man's poison is anothers favorite.

 

Mine has webber on the side of it

 

the edelbrock carbs are a good carb (under 650 cfm) for a mild performance engine unless you like to go around corners hard, the design of the fuel bowl and the jet placement cause the fuel to wash away from the jets on one side of the carburetor if you corner hard in one direction and if you turn the other way the jets on the other side will have the same problem.

the off-idle/transistion system is not designed to supply enough fuel for most engines on the 750 & 800 cfm carbs of this design, that is why so many of the owners of these carbs will complain of a lean off idle hesitation problem at part throttle. The fuel bowl volume/size is the same with all the afb/performer and avs/thunder carbs from 500 to 800 cfm. The only real change they do to the off road carbs is a spring loaded needle and seat so i see no advantage to that for a application such as a Corvette.

the 600 and 650 cfm carbs from Edelbrock are good carbs and easy to adjust but they do have thier limitations so if you are after maximum power think about a Holley, Quick Fuel or Demon carb (or a Q-jet).

the Edelbrock carbs are made by Weber (Magneti Marelli) who bought the patents from Carter so they are the same basic carb but the calibrations are slightly different.

henry @ olescarb

 

Single plane and cam I wouldnt use one.
Latest Holleys out are pretty nice, they have come a long way.

 

Good to know.

Fully buying what your saying.

How are they making the AVS 800 work on an 555ci BBC?

 

Guru, the 800 Thunder/AVS works well on a dyno but a dyno does not go around corners nor do they run the dyno at the light part throttle operating conditions you will see in "normal" driving.

Some people have good luck with the 800cfm AVS but i have seen ones that go so lean at part throttle that the choke valve was blue from the amount of backfiring it was doing. The comment from the Edelbrock tech line was it must be a engine problem but when they were told it was one of thier engines they had no further comments.

Henry @ olescarb

 

Well there ya go I guess.

 

Mine too!

 

if i corner to fast(too fast for an average car but pretty common with a vette) with my edelbrock i smell gas. i also get a hesitation on accel after cornering. i never bothered to look into it because i got the carb for free and plan on replacing it eventually.

 

I may have missed something here but what would be wrong with using a well built Quadrajet?

BigBlockk

Later.....

 

Well maybe I'm NOT the only one to experience problems with the Edelbrock AVS 800cfm carb after all.
These are the exact problems I had. Motor would hesitate badly just off idle. Caused no end of frustrations and several near incidents of young wannabe's rear ending me when motor would cough from the lights. Also doing U-turns with motor idling would stall the motor.
Could NOT get a workable combo of jetting/metering rods to overcome the problem.

Edelbrock carb has been ditched and a Holley Street HP 750cfm double pumper has been fitted. No issues with hesitation now, and throttle response and performance has improved markedly.

 

I used an Edl 750 carb on a single plane for 10 years.

during that 100,000 miles I went around a few turns without a carb problem.

If you can run out a float bowl .......... your fuel pressure is low


I had the Edl carb when I ran some Nevada open road races. The Silver state classic is 92 miles long and I averaged right below my class limited average of 150 mph. with slow 50-60 mph turns and 174 mph on the straights

 

I put an Edelbrock 650 AVS Thunder series carb on my 74 about 4 years ago and, other than an ocassional adjustment for weather conditions, its been trouble free, something I can't say about the two Q-Jets I used before (and one was brand new).

 

Find a "Mopar Dude" (easily spotted at any car event, they still wear big bellbottoms, have a "bikers wallet" on a chain to their belt, and big sideburns) they have been playing with Carter AFB (Awful Freeking Bad) and AVS (Are Very Shi**y) carbs since the late 50's and 60's when they were the carb of choice on Chrysler Products. GM only used 2 types of carbs on C3 Vettes: Rochester 4BBLs and Holley 4BBLs (for the "real fast" Corvettes.) For anyone who want to tell me about the Rochester dual throttle body EFI on the 82 Vette, all I can say is you have my sympathy for your pain and suffering. Maybe Edelbrock in all their wisdom will bring back the "Thermoquad" 4BBL carb of the early 1970's, I still have some Carter "Strip Kits" for those somewhere in my stuff

 

The carb gurus all agree that the Carter AFB/Edelbrock carb is junk - carburetor book author Doug Roe, carburetor book author Cliff Ruggles and our own Lars. Then last December I went and bought a '72 Pontiac Le Mans with a 400 topped by an Edebrock 1406. I can now speak from experience when I say this is an awful carburetor. I sent a Q Jet I had sitting on my shelf off to Cliff to have it rebuilt and should get it back in June.

 

I disagree. Holley is just a host of problems. I plunked the #1406 on my 1967 four years ago and have never touched it since. It's like an Energizer Bunny: just keeps going and going.

 

Let me sum it up.Make a sharp fast u turn and the Eldelbrock carb will out of 10 times stall the engine if you don't play with the gas pedal.Almost all Edelbrock carbs have some sort of hesitation just off idle or on very hard accel.The carb has limited amounts of tune-ability,such as only 3 adjustments for the accelerator pump.The good stuff about them they holes a tune very well and have a great idle.They also can adjusted for fantastic mpg.Easy to install.