I bought a 3x2 set up for my 292. all three carbs have a 7.5 power vavle and middle carb has 56 jet and ends have 52 jets. I am thinking I should plug off power valve on two end carbs and change jets so middle has 52 and ends have 56. However, I am just guessing after reading article after article. anyone have any real life experience or knowledge of what I should do....thanks
The center carb should be set up as if you are running a single 2-bbl setup. It should have standard jets, accelerator pump, power valve, choke, etc. You'll be running on the center carb alone 99% of the time. The end carbs should have all the fancy stuff removed, the idle p***ages blocked and the ****erflies fitted so they do not leak air when they are closed. This will allow you to tune the car with only the center carb operational, the end carbs completely closed. Use a progressive linkage which begins to open the end carbs at a point above your normal cruise speed, and at a faster rate than the center carb so that all ****erflies are wide open at wide open throttle. On a street car I'd be very conservative in your opening rate so as not to over-carburate the car as you approach WOT to the point that it's fussy. Perhaps opening them half way at WOT would be a good place to start, and work your way up from there. Once you get the car set up so that the end carbs begin to open at the right time and the correct opening rate established you can fool with the end carb jetting. As a practical matter you'll want to avoid going too lean at WOT. Going too rich isn't going to hurt anything but won't make you any more power. The seat of your pants...and your spark plugs...are you best friend when setting up a stick-shift car. An automatic is a bit more complicated since you don't get very good feedback through the converter, but the same principals apply. Hope this helps.
There's a Holley 94 group on HAMB but I have not found anyone that wants to be useful. If you really want to get into the "science" of those carbs do a posting on the main page and prepare to do some reading. I set my 94's up to be both primary carbs with 4.5 power valves and adjustable main jets for my 300 Ford six.
Yes, with two carbs they are set up to act jointly. You can do the same thing with your triple carbs if you want by setting up the end carbs to be the primary carbs, with the center carb coming in later. Probably won't be very efficient, though, because the manifold is not designed to work in that configuration. This works kinda like four barrel carb with all four barrels working all the time. Two two-barrels was very popular on street driven flatheads, but never seemed to catch on with OHV motors, probably because the early OHVs were available with 4-bbl carbs from the factory. It didn't take long to figure out that a 4-bbl carburetor had greater flexibility...and greater performance potential...because they were just like two two-barrel carbs, only with the advantage of a progressive linkage. It was the advent of a dependable vacuum-operated secondary system that sealed the deal, and fated multiple 2-bbl carb systems to the back burner of history. Too bad, multiple carb systems look so much cooler...
I've had several multi-carbed cars over the years.... with a bit of fiddeling and fine tuning there is nothing that can replace the feel and sound of those carbs when they all kick in!
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