davep_96

What size carb should i run with this setup: sbc 350, edelbrock performer rpm intake, comp cam 218/224 .462/.469, hooker headers, vortec heads, 9.5:1 comp ratio? I was thinking of the holley 600 cfm carb but im not sure if that is the best choice. Any help would be great. Thanks, Dave

ZONES89RS

iTrader: (25)

My vote would be a Holley street avenger 670, they are excelent carbs for a muld app and the 670 is good for 400-500 HP, Ebay has a deal right now from a seller who has them going for 150-175$, they were basically display carbs but have never been run, i plan on buying one.

1997bird

iTrader: (2)

That 670 is too much carb for that much cam, a 570 would be a better choice for tuneability.

RAGENZ28

iTrader: (5)

Cubic inch (350) x max rpm (6000) or so with that cam / 3456 = 607cfm that would be at 100% V/E which your motor won't use. I think 600 is good compromise.

If you went with a bigger cam I would consider a 650cfm, if it was bone stock then I would lean towards a smaller carb. 600cfm is my vote for what you have now.

ZONES89RS

iTrader: (25)

Yea, a 670 is perfect, if he goes bigger he wont have to change carbs. It usually happens that way.

JakeFusion

iTrader: (7)

The difference between a 600 and 670 is neglible. Plus, with a 180-degree dual plane manifold, you can run a lot more carb than you would normally anyway.

As for the Street Avenger, that's probably the lowest performing carb Holley makes, but it has good street manners.

If you can get away with running without a choke, I'd go for the Holley 4150 Street HP 650CFM Carb. The HP series is pretty much the best off-the-shelf carb you can get. The street version is tuned for throttle response and drivability. It makes a lot more power/torque everywhere compared to the Avengers and Douple Pumpers too.

1997bird

iTrader: (2)

Here is my story as to why I say that the 670 Street avenger is too much carb. I have a 383 stroker that is 10.18:1 with a ported Performer RPM intake, ported Performer RPM heads, Retro-fit Hyd. roller cam (214/222 @0.050" duration 112*+4*), MSD ignition system, and long tube headers. I had a 670 cfm Street Avenger carb on it (it is rated 10% less than what it really flows(737 cfm), as per the Holley rep that was at our companies convention in Las Vegas, NV when I used to work for CSK Auto) in a 5000 lb. truck that I had tuning issues with from being to rich. I dropped back to just a regular 4160 Holley 600 cfm carb that I had on the shelf and cleared up my over rich conditions. I then went to the 570 cfm Street Avenger and had the best of bolth worlds as the single feed 600 cfm carb lacks in the performance department in my opinion. I also gained an increase of fuel mileage with the 570 over the single feed 600 carb as well.

JakeFusion

iTrader: (7)

Did you play with the jetting at all on the 670?

1997bird

iTrader: (2)

Yep! I tune alot of carbs for the locals here, so I know what needs to be accomplished in order to get things to run correctly. Now then this same carb in my dad's 79' Camaro with a 355 and a much larger cam ran just about right with tuning (still slightly rich but not by much). It was 9.4:1 compression with a Air-gap intake, 90 hrs of port work on some GM heads (2.055/1.6), solid cam, headers, MSD ignition, and 3300 lbs of weight.

382ssz28

iTrader: (24)

What 1997BIRD is saying is Airspeed! It is your best friend. It is harder to jet down than to jet up. The smaller airhorn creates faster air for better atomization. Example: My good friend built a 468 for his 69 Chevelle that he drives every day possible. It runs 11.20's. I suggested an 800 Holley DP after doing some math, (thank you RAGENZ28). He wanted more so he tried an 850 and 950HP carbs. Not only did it kill the power, it killed the throttle response and mileage. Everything is a mathmatical solution. Try the 570. You won't be sorry. Just an opinion.

JakeFusion

iTrader: (7)

I still think the Holley HP carbs are the best out there. There is a 600 CFM 4160 version availabe. Might be worth a shot.

1997bird

iTrader: (2)

Thanks, 382ssz28!! The pressure drop against the venturis with that small of cam is not going to be enough to warrent a 670 cfm carb, in my opinion. I would also stay with the Street Avenger line of carbs over a 4160 (single fuel feed) 600 cfm carb. You will have better throttle responce, more power, and better fuel economy, atleast that was my experience with the Street Avenger line.

1320_Racing

iTrader: (44)

I would go with a 600 CFM no larger than a 650 CFM. I will be running the same set up with an Edelbrock 600 I'll let you know how it works

bluebeast

iTrader: (1)

a 650 double pumper would be nice...... i used a 700cfm dp on my basic 350ci with a mild cam and the car pulled big time on another 67 camaro with a street avenger 600cfm...... my car had good power down low back then too and im sure that my carb didnt meak me out run him but before i had it i ran a older vacume secondary 700cfm and the new doubler pumper series was so crisp and clean running and the power cam in so much harder than the vac sec..... if you dont know how to tune a carb and just want to throw it on and drive then get a street avenger or edelbrock but if you want a better carb but will need to learn how to tweek it a 650-700cfm double pumper is the way to go in my opinion.... but i will add that a DP holley carb comes with a neat DVD that teaches you how to tune tweek and work on a carb if you dont know already