Thread: Which Carb for my 350?

Tweet

Originally Posted by wingman9

I agree with the dualplane manifold idea, but a Holley Street Avenger would be a good carb choice, in my opinion. The 570cfm version (0-80570) is good to about 5000 rpm. If you need more rpm, which is highly unlikely, the 670cfm version (0-08670) would be a good choice. I had a 600 Holley 1850 on a 350 sbc, replaced it with a Street Avenger and I got much better results.

Thanks! I'll take the into consideration.

As for the intake manifold, lots of fellows with street machines have chosen the Edelbrock Performer, part number 2101...This intake is rated by Edelbrock as being effective from idle to 5500 rpm's.
http://www.summitracing.com/parts/EDL-2101/
I disagree with this choice. This is a very low rise dual-plane intake and the only advantage I see to it is that it is aluminum, which takes some weight off the front of the vehicle as compared to a cast iron intake. It certainly is not a performance manifold in my opinion.

Stepping up to a high-rise, dual-plane intake has shown to give an increase of 30-40 horsepower on my DynoSim software engine builds and this seems to be borne out by what I hear from racers at the drag strip and what I read on other forums. One such intake would be the Edelbrock Performer RPM, part number 7101....This intake is rated by Edelbrock as being effective from 1500 to 6500 rpm's.
http://www.summitracing.com/parts/EDL-7101/
You might say, well it doesn't become effective until 1500 rpm's as compared to the Performer, which Edelbrock says is effective from idle. Three things to be considered here....
1. You don't use any power from idle to 1500 for any performance advantage purpose whatsoever. It's just a transition from idle to a useable rpm range.
2. Most any enthusiast who does modifications to a motor will also change the torque converter to one that is a little looser and allows the motor to "come up on the cam". Most fellows will choose at least a 2000 rpm stall unit, which is well past the 1500 rpm starting range of the RPM intake.
3. Don't worry about the high end of the range, the 6500. If you ever do get the motor to that point, it won't be for but an instant anyway. The RPM will do an exemplary job from 1500 to 5500 in a common sense street motor.

Edelbrock also offers an "Air Gap" model in the RPM, rated at the same 1500 to 6500 rpm range as the standard 7101, but with an opening under the carb pad to supposedly cool the intake charge, making it more dense and therefore making more horsepower.
http://www.summitracing.com/parts/EDL-7501/
I don't know, this may or may not work. I do know one thing though, if I lived in an area where it got cold, I'd probably get tired of waiting for the motor to get warm so that it didn't stumble and according to David Vizard, there is only 3-5 hp difference anyway. The standard RPM would be my choice.

Optionally, Weiand made a very nice dual-plane, high-rise intake called the Stealth, under part number, I think, 8016, but they are no longer available new, having been replaced by the Speed Warrior, part number 8150...
http://www.summitracing.com/parts/WND-8150/

Holley also made a nice manifold that is no longer available new, part number 300-36. There is a 300-36S model made now (Maybe the "S" stands for Street, I don't know for sure). If the runners are smaller/shorter or the carb base is lower, then I doubt it will perform like the original 300-36. Here's an original for sale on Racing Junk....
http://www.racingjunk.com/category/0...or-300-36.html

Scuttlebutt has it that an Airflow Research engineer has said that there is no better intake for a street or street/strip motor than the Edelbrock RPM. I can't attest to the truth or untruth of it, all I know is that if I were going to build a carbureted small block that would be rpm-limited to 6500, I would use an RPM or find a nice 300-36 like the one I linked on Racing Junk.

And now viewers, for your edification and entertainment, here is a compilation of measurements that I stole from BeaterShark on the Corvette Action Center forum....

"SBC aftermarket intake manifold heights. Hopefully this will be useful to someone.

Here are some manifolds and their (advertised) heights I found when I was looking for a manifold to fit under my hood.

DUAL-PLANE:
Edel Performer (2101):
Front: 3.50" Rear: 4.60"

Performer Air Gap (2601):
Front: 3.72", Rear: 4.92"

Edel Performer RPM (7101):
Front: 4.20", Rear: 5.25"

Edel Performer RPM Air Gap (7501):
Front: 4.20", Rear:5.25"

Holley Street Dominator (300-36):
front 4.44", rear 5.33"

Weiand Stealth (8016):
front: 4.18", rear: 4.50"

Weiand Action Plus (8000):
front: 3.75", rear: 4.63"

Weiand Action Plus (8004):
front: 3.50", rear: 4.00"


SINGLE-PLANE:
Edel Torker II (5001):
Front: 3.53", Rear: 4.63"

Edel Victor Jr (2975):
4.58" (This is the height at the center of the carb pad and the carb pad is at a 3 degree angle down toward the front)

Weiand Team G (7525):
front: 3.50", rear: 4.50"

Weiand Team G (7530):
front: 3.63", rear: 4.56".

Weiand X-celerator (7546):
front: 4.38", rear: 5.31"

Weiand X-celerator (7547):
front: 3.09", rear: 4.06"



I don't know what the stock manifold height is, but I'd bet it is real close to the Performer."

You could also opt for an Offy 360 part# 6007,but they are a little pricey and IMHO the best after market intake manifold available.

Originally Posted by NTFDAY

You could also opt for an Offy 360 part# 6007,but they are a little pricey and IMHO the best after market intake manifold available.

How did I know that was coming?

Originally Posted by techinspector1

How did I know that was coming?

I could have suggested an Isky cam, but I thought that might be a little overkill.

Tech inspector... Holy cow thank you. That's exactly what I was looking for. Any thoughts on a good carb? Dual Carbs? Again... Thank you!

Originally Posted by M22KLARS

Tech inspector... Holy cow thank you. That's exactly what I was looking for. Any thoughts on a good carb? Dual Carbs? Again... Thank you!

As far as what I consider the best 4-bbl carburetor ever designed, that honor would have to go to the Rochester Quadrajet. Original equipment on millions of General Motors vehicles through the years, the Q-jet was fairly complicated to rebuild and tune and not many fellows spent the time to get to know how to do it properly. Cliff Ruggles is one of the best known experts on Quadrajets and he says that a properly set up Q-jet is very close to electronic fuel injection in performance.
http://www.cliffshighperformance.com...history_1.html
If I wanted to build a state of the art carburetor motor (I guess that sounds like an oxymoron, huh?), I would use a Ruggles Q-jet and an Edelbrock RPM Quadrajet intake....
http://www.summitracing.com/parts/EDL-7104/
(notice how the secondary bores are larger than the primaries? That's for the huge Q-jet secondary throttle blades to clear).
Then I'd set the fuel pressure at 5 psi at the carb inlet and mount a 14" x 4" air filter assembly.
Any of the enthusiasts on this forum who are around my age can remember the BA-WAAAAAAHHHHHH sound the carb would make when you'd wood the loud pedal.
Call Cliff up and talk with him. It's at least worth a phone call to find out about the cost and such. He can tailor the carb to your vehicle and your driving style.

As far as a dual-4 arrangement, I'd use the Edelbrock RPM Air Gap #7525...
http://www.summitracing.com/parts/EDL-7525/
and two 500 CFM Edelbrock Thunder Series AVS #1803 and 1804 carbs. HEI will not fit with this intake. Must use small diameter distributor.
http://www.summitracing.com/parts/EDL-1803/
http://www.summitracing.com/parts/EDL-1804/

Thank you. You are practically building my motor. I'm just buying the parts and doing the installs!

Ok I sent out into the garage and got some inf on the motor. Currently on the motor is an Edelbrock Performer intake manifold and an Edelbrock 1401 carburator. If I don't use the Victor JR, where do I go from here to make more power? Still don't know what cam is in it currently. Something... but not sure what.

Step up to the Performer RPM dual and some better dual carbs?



P.S. my problem with this car is, I bought it from my father who bought it a few years ago years ago and never did anything to it but drove it. He has no clue what's in it. And I can't find any info on the previous owner to call and ask.

performance wise probably nothing .. single carbs can be had plenty big enuff to do the trick .. multiple carbs just have a " wow " effect

Except for fuel injection, nothing works better on an engine than a properly matched 4 barrel carb and intake, taking into account smoothness, reliability, economy, and cost. But they just aren't as "cool" as a couple or bunch of carbs perched atop a motor, expecially in a hoodless car.

Hot rods, by their very nature, are compromises in all respects. They are not as safe, comfortable, economical, or sensible as the stock passenger cars we drive daily, and we know that going in. But that is not the reason we build them. We build them for the excitement and the looks we get from every other driver on the road who isn't having as much fun as us.

But for your setup, stick an Edelbrock 500-600 carb on a good dual plane intake and it will do everything you want it to do.

Don

Oh, and I saw Richards comment about the 5 psi being right for an engine and he is dead on. I just pulled the Holley 12 psi pump out of my 27 and put a Carter 5 psi in and the car runs better and is actually getting better fuel mileage, considering the 2 x 4 setup and 4:30 gears.

Originally Posted by M22KLARS

Any thoughts on a good carb? Dual Carbs? Again... Thank you!

Put a Barry Grant carb on there.........


Sorry, I saw carb and it just popped in my head.

It's got a 10 bolt rear end. Not sure on gears. Gotta open it up and look. And mustang II front end. I'm assuming that whoever built this merged this body with an older camaro. (mid to late 60's?) It even has camaro buckets.

Originally Posted by pro70z28

Put a Barry Grant carb on there.........:LOL

But don't wait long..they're soon to be collector items.

Dont want to hijack this thread, but I have the same question, same engine, perhaps the same use.

I currently have an old edelbrock 1406 on a edel high perf intake manifold. Neither myself or another old school mechanic can get it tuned just right.

So I have been looking at alternatives, get another rebuilt 1406, try to rebuild it myself, or look at a holley.

On other forums I have seen folks say that a vacuum secondary is the best thing since sliced bread. I dont believe that the 1406 has a vacuum secondary but the holley O-80570 does.

The question is Are vacuum secondarys better in a street/mild performance engine better?


Thanks!