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3 deuces- adjustment

18K views 3 replies 4 participants last post by  timothale 
#1 ·
Help!

I Just Bought A 1930 Ford With A Corvette 327 An Offy High Rise With 3 -2 Barrel Rochester Carbs. The Center Carb Is The Only One Hooked Up And The Car Runs Great. I Would Like To Hook Up The Other Two Carbs But I Am Not Sure About The Adjustments.

The Front And Back Carbs Have No Adjustments Whatsoever On Them But The Middle Carb Has The Basic Stuff. I Bought A 3 Deuce Sync. Tool From Speedway Motors. It Has A Vaccum Ball And All 3 Carbs Are Supossed To Read The Same At About 800 Rpm. The Front And Back Carbs Are The Same With Out Adjustments But The Center Is The Same Except For The Usual Adjustmants.

My Questions Are -- Should The Front And Back Rochesters Have Any Adjustments On Them? Should The Front And Back Carbs Read The Same Vaccum Since They Are Alike And Then Shoul I Adjust The Center Rochester To Match Them At 800 Rpm Since It Is The Only One With The Adjustments?

I Have Rochester Bokks And Have Done Alot Of Reading But Still Am Confused.

Any Help Would Be Appreciated

Thanks
Rivergunner
 
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#2 · (Edited)
It sounds like you have the correct outer carbs. Unfortunately I believe you wasted your money on the synchronizer. The proper way to set up Rochester tri-power is just like the factory did it. Use a progressive linkage. Set up this way the outer carbs open at 1/2 to 3/4 throttle (depending on how you adjust the linkage). There is no need to "synchronize" the carbs at all. Now if you were running 6 Strombergs on a log manifold all straight up (no progressive linkage), then the synchronizer would be appropriate, but it is not needed and will do no good with Rochesters set up on a progressive linkage.

The outer carbs on a Rochester 2G tri-power have special (thicker) butterflies which seal completely. By doing this no air/fuel mixture is allowed into the engine at idle therefore no synchronization is necessary. That's why they have no idle circuits. They are designed to open at higher throttle settings, just like the secondaries on a 4 bbl.

This is one style of progressive linkage. As the center carb opens to half throttle it opens the front carb and that one opens the rear carb at the same time. Simple, needs no synchronization and also economical when it comes to gas. Depending on the year of your outer carbs they may have the connection on the opposite side (mine do) but the linkage still works the same way.

 
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