Just bouncing some thoughts around. Ive got a 2300 (500cfm) 2bbl and I'm curious if it would outperform a 1460 (600cfm) 4bbl?
According to what Ive read the 2300 is a mean SOB ( half of a 4150) and is considered a top ofthe line performace carb. Ive been looking for my 2 to 4 adaptor to play with this idea but I cant find it so I guess I'll just have to "bench race" the idea for awhile.

 

Probably not.

 

Keep in mind that the two-barrel carbs are rated at 3" vacuum drop, and four-barrels rated at 1.5", so the 500 CFM two-barrel becomes (500/1.414) 354 CFM at 1.5" mercury.

 

Bingo, big difference is in flow rating method. The only reason to under-carburate is if you are building a motor for a restricted racing class that specifies it.

 

I'd never use a two-barrel unless forced, personally. Normal two-barrels (like a Rochester DualJet) have real problems in that the primaries have to meter fuel from idle to WOT and everything in between. No matter what you do to set them up, they either seem to not have enough fuel at WOT, or they're too damn rich everywhere else.

I've only used one sequential 2bbl, the VaraJet E2SE, and I hated that carburetor with a passion. Talk about a finicky bastard.

I even spent money swapping out the dualjet on my 3.8 Buick for a Quadrajet. Believe it or not, it was a NOTICEABLE improvement.

 

Webber makes a few. They work pretty well really....like miniature double pumpers. They're popular with 4x4 guys running smaller motors because they maintain idle at some funky angles..I've seen one stay running on a jeep that was about 60 degrees over.

For our purposes tho there is no reason to run a 2bbl except for class restrictions. 4bbl is the way to go.

 

I can vouch for the varijet, that thing sucks on my 2.8. It runs like crap for a substantial amount of time until warmed up, and will die and stall on decelleration after being rebuilt and all vacuum lines checked. My quadrajet on my t/a has stalled ONCE because I was dumb. The varjet used to stall 3-4 times a day.

 

That problem with your 2.8 sounds like the electric choke isnt getting power. If the choke isnt getting power the choke pull off will go wide open the second the cars started causing the problem you describe.

I dunno I'm still going to play with the 2300, I found another one at the junk yard $5 Two of them might be interesting.

 

Dose any one know of a a person makin a 6pack for a sbc.

 

Oh yeah. Edelbrock makes one still, the C-357-B. Too much linkage and tuning for the performance IMHO, but it looks neat.

 

Yeah that look's sweet as hell, how much dose one cost and dose it do any thing in the perforance range.

 

That Edelbrock thing is always good for a laugh... Rochester 2-barrels!!!! Talk about a grocery-cart piece if there ever was one.

That setup (along with the old Pontiac "Tri-Power" setup it mimics, even uses the same carb #) belongs in the same category with their triangular air cleaner: shiny, massive garbage that sits on top of the motor where it's the first thing spectators see when you pop the hood, so 9-year-old boys can oooh and aaaah over all the shiny playpretties as the car sits in the parking lot with all of the other non-running, or barely running at best, "street rods". Totally NOT performance oriented.

Now if they only made one that you could put 3 Holley 350 2-barrels onto, then maybe you'd have something that could compete with a single four-barrel.

The old Holley 4412 is probably the best-running 2-barrel ever made, but it still isn't going to compete with a properly sized and tuned 4-barrel. The bores are as big as a 750 4-barrel, so on a motor that's small enough to get by with its flow, the low-speed driveability is just as horrible as it would be if you stuck a 850 on a 305.

I think I still might have one of them hanging around someplace; I had it on a 59 Pontiac with a 389 I used to have a disgustingly long time ago..... it ran about 50% stronger than the Rochester (just like that 3-deuce joke) it replaced, but still not as good as a stock 4-barrel car did.

 

Yes, I have to agree that multiple carbs always looks good. Can't say they always perform as well as they look... as in this case.

The manifold, fitted with three Rochester 2GCs was dyno tested in January's HOT ROD. It made between 8 and 12 HP less than a 625 cfm Road Demon carbueretor on a Performer RPM Air Gap intake.

As tested, the manifold, carbs, air filters & linkage cost a total of $2300. Yes, it's a lot of money but think of all the 9-year old boys you would impress!

Now if you want a serious multiple carb setup, look into a set of four Weber IDAs, carbs that were meant to be one throttle per cylinder and work very well all round. Streetable, among the best for low-end throttle response, good mileage. Just really expensive to buy and tune. Can't have it all.

 

I couldn't resist, this one looks hot too. These are DCOE Webers.

EDIT - Just for the sake of curiousity I priced these induction kits from Pierce Manifolds where I got the pics. The kit below is US $2850, the one above is $3230. Gotta love 'em.

 

Jeez. I think I'll stick with my $25 Ebay Qjets.

 

I’ve messed with “three deuces” before. My dad wanted them on his ’63 327 Impala for looks. His set-up was an offy intake w/ the Rochester 2G carbs. Actually, the car ran better with the stock Rochester 4GC and intake (you old timers will know that the 4GC is a SMALL 4 bbl )

 

First time I saw a 4GC I thought it was a carter product, perhaps an AVS. The owner corrected me - and I think it was originally from his '65 327 Impala. It had a factory vacuum gauge on the console.

 

LOL those are the same carbs a friend of mine has on a VW bug 2 of em, LOL 65mm.

Would be neat looking but Id rather have a blower for looks and speed.

 

I ran dual Weber 40 IDF's on a '70 Bug, what an ABSOLUTE pain in the tail to keep in tune, keep the cheap dimestore linkage that came with the kit adjusted so they were both synchronized.
Ran like a bat out of hell when they were right, but when they weren't.....

Stick with a single carb, you'll be mucho happier!

Eric