Can a SBC run on middle of 3 deuces??

I posted before about getting a '74 350/turbo 350 with 55k original miles. Thanks for the help on a safe way to get it cranked after sitting 15 years. We know that a '74 350 isn't a high power engine - it's got a 2 barrel. I've always liked the 3 deuce setup and thought I read years ago that you can run on just the middle carb. With adding paint, some finned valve covers, headers and a 3 deuce setup, it could be a good looking engine and still be super dependable on regular pump gas. Can you run only the middle carb on a 3 deuce setup...and if so, what would be the best carb/manifold combo to use? I'm thinking it'll still be a pretty much a stock engine with a few "look good" parts.

 

You certainly can just run on the center carb, but you should just hook up the end carbs progressively on a three to one ratio. Once you hit two thirds throttle on the main carb, the outers will cam over and all arrive at wide open throttle at the same time.

Don't assume you need an nasty motor to run trips. The reality is you will rarely hit all of them. But it won't look so poserish, if that makes sense.

This is coming from a guy who has run a couple of tri power setups.

I also can admit I ran a 6x2 crossram on a mild SBC and had to block the outer four to make it run half way decent.

 

Offenhauser is the cheapest. Two dummiy carbs on the front/rear with solid aluminum plates with gaskets 'over & under'.

Watch 'Highway Patrol' episodes about the guys with dummy carbs carrying dope, however! They were smuggling MARIJUANA in the 'dummy carbs'!
You may be subject to 'unreasonable search...'

 

x2 and even adjust the linkage out so maybe you have to be to the floor for them to all be open. looking at doing a triple intake on a 6 cylinder and its set the same way and ive heard nothing but good about it

 

If you only want the middle one functional,,but still want the look ,,block off the front and rear carb with a plate cut to fit between the manifold and said carbs ,,dummy fuel lines and linkage so it still looks the part..Then you are running on the center only

 

Yes it will work ,just like every one has said . thanks

 

Millions of small block Chevys came with a two barrel Rochester carb....itll run just fine. Just make sure the outboard carbs are blocked off underneath so you have a good vacuum signal to the center carb...

 

As ling as you have enough CFM to keep the SBC ticking over. If modified you might need to up the ante CFM wise

 

if you need a set I have one for sale -complete and removed from a running car for$700.00 pm me and I can send pictures

 

Center carb only runner for the last ten years,

 

1 4 bolt isn't a problem @ all, but...with a 3 bolt you're talking less than 200CFM, depending on the carb, 97s are only 150, not much carb there.

 

Atwater Mike & George X2. If I were running only the center carb it would have to be a Rochester.

 

I respectfully disagree on blocking off anything on a Rochester equipped setup. I've run these with a progressive linkage, and with a very minimal amount of fiddling, you have a good running and economical set up on the center carb, and plenty of power when the secondary carbs kick in.

Had a good running tri-power in a 59 Impala, which weighs just shy of 7 tons , with a 283 and a turbo 350. Very street able, yet when you jumped on it, even from a stand still, she would boil the weenies quite nicely!-MIKE

 

X 3. I'm running 3 Rochester 2G's with progressive linkage on my little 283 in my '33 pickup. Center carb is the primary, outer 2 progressively kick in. It screams real good. No need to block off the outer carbs.

 

I run progressive linkage on my three two's and it works just great on my SBC.

 

No problem! I cut off the fuel and air to the end carbs. on this 283 and it runs fine.

 

For you guys running Rochesters, how do you have them jetted center and outer?

 

I ran a Goodwrench 350 with tri-power. I also installed a slightly hotter cam because the motor was so quiet, you could hear the valve train. The tri-power was hooked up with progressive linkage and I never got into the outer carbs. On Sunday mornings I would take it up on the freeway and punch it just to drain the outer carbs. Car ran great, wide open, on such a stock motor. I think you'd be happier knowing it's there when you need it.

 

I've run both ways. But much prefer all 3 up and running progressive.
Wow. A 7 ton Impala. ....

 

Hook them all up and run them. You'll very seldom run the end two but the power is nice to have when you need it. As long as you don't over cam the engine looking for a lumpy sound, you'll be just fine. I ran an old Weiand 3 deuce set up on a stock 283 I had in a 56 chev. Drove it from Kansas to San Diego and got 19 mpg doing it. Never had a problem with it running progressive linkage. Aside from that, it has to be the most classic look on a sbc ever.
Side note...the end two on mine were gutted of all idle and choke assemblies and were basically dump carb's while the center had all that left in it. The how to was in an article that HotRod magazine ran back in '68 or 9. I followed it exactly and it worked perfectly. Go for it...don't be scared...you'll love it.

 

We ran three Rochesters on an Offy manifold on the 283 in our '58 Apache for years trouble free until an ASE certified mechanic in Colorado Springs adjusted them for my son when he had it in for an oil change and new plugs while at the Academy. He limped it back to Oklahoma at Christmas break and we got it going again correctly. Moral of the story... just because the mechanic wears an ASE tag on his shirt sleeve doesn't mean he knows any more than the oil change guy at Wal-mart.

We replaced the 283 with a 350 last September and the plan is to find something light (T-bucket, etc.) to stick the 283 in and run the trips again without a hood.

 

Here is a stock sbc (with fake Olds valve covers) with a 1/4" plate on top of the stock 2 barrel intake sandwiched under the functional middle carb. The end carbs are non functional but who would know but only a few savy motorheads!...and pretty cheap for a piece of plate and a couple of swap meet carbs.

Real end carbs should have special throttle plates to seal off against the carb body for zero vaccum leaks...price starts going up!

 

Well maybe I exaggerated a little. But them old boats were heavy for a 283.-MIKE

 

Just got the real deal running on mine last night. 283 with a 3 deuce set up. Progressive linkage and new base plates.
Thanks Josh and Steve Highley for helping out

 

You can, but why bother. Three Rochesters are amazingly simple to set up and run. I have run my set up on multiple vehicles over the last 25 years, 283, 327,s 350's. 25-30,000 miles on my old dd 66 c-10. Keep the floats set right, the fuel pressure down, and make sure you have the right base plates and butterflies for the outboard carbs. and dont block off the exhaust crossover if you live where it snows.

 

Run all three on a progressive set up and you'll be very happy. If you don't feel you have the skills to set it up properly, find someone with experiance to help you.

People who have any kind of multiple carb set ups and don't have them all functional are posers. Fact. They'll also tell you it's ok to put Oldsmobile valve covers on a SBC, run an alternator that looks like a generator and go with the imitation wood grain and vinyl leatherette upholstry.

For gods sake my man--if you're gonna build a hot rod then build one.

 

ran my 348 for years off the center carb, just removed the linkage to the other two carbs...

 

it'll work like stock

 

yeah but if your going to all the trouble to put it on run progressive linkage and use those babies once in awhile

 

I have 3 on my 392, they are progressive. Runs great, about 45,000 miles on this set up and going back and forth to Bonneville it get's about 18 mpg. When you mash the throttle it rocks, No issues, slight bog if you feed it in all at once. It really dumps a lot of fuel when all 3 are wide open.
chuck