buffblazer
1/2 ton status
would a 750cfm edlebrock carb be to much for a 350 bored .40 with stock heads? will a 600cfm be to small? seems like there is a big jump there im wanting the most performace i can get.
CK5
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carburator size to big???
- Thread starter buffblazer
- Start date
lectric80
3/4 ton status
600 CFM will be ideal. 750 would be better suited to a larger engine, it might work on a 383, but would require some tweaking to get it right.
Mike D
1/2 ton status
At 5000 rpm a naturally asperated 350 cu. in. engine will draw in about 450 CFM of air. The 600 CFM carb should give you better overall throttle responce. If you contact Edlebrock find out how you can custom tune their carb ( by replacing the secondary metering rods ) to optimize any changes you have made ( cam, heads, exhaust, etc. ) over stock. A little tweeking on a carb could greatly improve engine perfofmance.
Thunder
3/4 ton status
5 to 600 CFM is all you need on a stock or mild build 350 that wont see the other side of 5K rpms
Most peope tend to over carb their engines. The only time you need a 750 on a SBC is if it is a high performance engine seeing high RPMs.
You can put a 750cfm on a SBC and it will run ok. But you will loose low end torque and take a big hit in gas MPG.
Most peope tend to over carb their engines. The only time you need a 750 on a SBC is if it is a high performance engine seeing high RPMs.
You can put a 750cfm on a SBC and it will run ok. But you will loose low end torque and take a big hit in gas MPG.
Thunder
3/4 ton status
Unless its a Q-jet
Very true
! Beings the post was about edelbrock I was refering to square bore carbs.
But
Edelbrock Thunder AVS series carbs are very similar to Q-jets. They are a spread bore. The 650 CFM would be great on SBC.
Very true
Beings the post was about edelbrock I was refering to square bore carbs.
But
Edelbrock Thunder AVS series carbs are very similar to Q-jets. They are a spread bore. The 650 CFM would be great on SBC.
The only other spread bore carbs I know of are the Holleys and that thing that came on Dodges...what was it? The Thermoquad or something?
Thunder
3/4 ton status
Edelbrock Thunder AVS carbs are a copy of the old Carter AVS carbs. They are a spread bore with an air valve like Q-jets and Thermoquads. But not made out of plastic like the old Thermoquads. Chevy used them for a few years in the mid 60s and dodge used them up untill the early 70s
The Edelbrock AVS carbs are built by Webber.
The Edelbrock AVS carbs are built by Webber.
The Edelbrock site lists them as square-bore. If Edelbrock was still making, or if I was aware they were still making a spread-bore carb, I would've bought one.
Instead I bought a slightly used Edelbrock Q-Jet.
Thunder
3/4 ton status
AVS are a spread bore carb. I garrentee you that. They list them as square bore because they fit square bore manifolds. On AVS carbs the primary bores are smaller than the secondary. Like on Q-jets. It is a classic spread bore design. But dont believe my words. I will let some pics do the talking for me.
The carb on the left is the Thunder AVS. The carb on the right in a regular Performer carb. You can easily see the diference between the 2 carbs.
The AVS on left has smaller primaries than the secondaries = SPREADBORE.
The performer on the right venturies are all the same size= SQUAREBORE.
BTW Edelbrock still sells their new Q-Jets too. At least untill their stock on hand is gone.
http://store.edelbrock.com/edelbrockcarbsq-jetapplicationcarbs.aspx
The AVS on left has smaller primaries than the secondaries = SPREADBORE.
The performer on the right venturies are all the same size= SQUAREBORE.
BTW Edelbrock still sells their new Q-Jets too. At least untill their stock on hand is gone.
http://store.edelbrock.com/edelbrockcarbsq-jetapplicationcarbs.aspx
I know what you're saying... I suppose we could be splitting hairs here. My 600cfm Performer could be *technically* considered spreadbore based on that, because the primaries were a tad smaller than the secondaries.
However, if you put up a pic of the undersides of the AVS and a Q-Jet, the AVS would look pretty "square" in comparison. I think of a spreadbore carb as having two radically different sizes between the primaries and secondaries. The difference in the AVS is not as extreme as a Q-Jet. In my mind, the AVS would perform closer to a AFB than a Q-Jet. Probably somewhere in the middle, but still not in Q-Jet territory. That's just theory though...I'm sure you have more experience with the AVS than I do.
Thunder
3/4 ton status
Dont really have much experience with them. I had a Carter AVS on my old 67 Camaro RS.
Chevy only used them for a few years 66-67 and only on some models of 327s. It was a PIA to get parts for so I swapped it out for a Q-Jet. Camaro Ran better with the Q-Jet once I got it tuned good.
Must be the reason Q-Jets were used by GM for 20 some odd years.
Chevy only used them for a few years 66-67 and only on some models of 327s. It was a PIA to get parts for so I swapped it out for a Q-Jet. Camaro Ran better with the Q-Jet once I got it tuned good.
Must be the reason Q-Jets were used by GM for 20 some odd years.
Dont really have much experience with them. I had a Carter AVS on my old 67 Camaro RS.
Chevy only used them for a few years 66-67 and only on some models of 327s. It was a PIA to get parts for so I swapped it out for a Q-Jet. Camaro Ran better with the Q-Jet once I got it tuned good.
Must be the reason Q-Jets were used by GM for 20 some odd years.
Indeed... and also the reason I sold my AFB and got the Edelbrock Q-Jet...
buffblazer
1/2 ton status
sooooo after reading all that and my headache went away would the 600cfm performer carb be just fine, or would i be more happy with the 650 off road carb
would the 600cfm performer carb be just fine, or would i be more happy with the 650 off road carb
Thunder
3/4 ton status
I think you would be happier with the 650 offroad AVS. The performers dont do too well offroad.
