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235 chevy dual carbs

6K views 4 replies 3 participants last post by  F&J 
#1 ·
I have dual 1bbl rochesters on a 56 inline chev 235. it ran great with one carb but two seems to be too rich for her. I am wondering if anyone has had experience building a progressive linkage for this set up or if one is sold? so far all I have found is the single linkage rod connecting both carbs and opening them both at the same rate.
 
#2 ·
Some say you can't run 2x1 or 2x2 on a 6 OR a v-8 using progressive, but there are people out there that claim theirs has worked fine.

A switch to 2-ones should not make it richer. Each carb is open less at a certain rpm, than if one carb was used.

Even the little Corvair 6 had FOUR 1 barrels as an option.

Sounds like there is something wrong with one or both carbs.

I'd try running it on one; and if it runs OK on the road, then unhook that one and try running on just the other one. Hopefully one will show a problem. And if it does run Ok one one,maybe it will survive on a progressive linkage.

Some thread I read just this week about inliners w/ 2x1. I think they said it would not run great until it got fully warm because their intake did not have the factory exhaust-heated abilities. So, during warm up, the manifold ices and that definately causes richness & poor running/idling.
 
#3 ·
I have swapped out several carbs.. finally got some n.o.s. ones that run pretty well. I think youre right about the heat problem. there was an old fenton intake on ebay that had a pipe through it. it was water heated. now I know why. it went for too much $$ for me. it may run better when the weather warms up. I was just curious about the linkage, I like to make my own stuff and was just looking for ideas
 
#5 ·
did you disable the idle circuit on the rear carb? that has to be done. Multiple carbs also have to be synchronized
Well, those facts are true But! Idle circuit on one being shut off is true only if it has progressive linkage.

2 carbs DO need sync IF they are running non-progressive linkage.

I think maybe what you meant is like on trips with progressive, THEN you want to sync the 2 outboard carbs at high rpm.
 
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