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The Holley tech guys aren't that sharp?? Gee, and I thought they were just being difficult. Actually, when Holley got bought out a few years ago, they let 75% of their staff go. And guess what, the older, experienced guys that really knew carbs were some of the first. Holley is "Going in a new direction" and needed new, younger personell that are more familiar with fuel injection and what not. Most of 'em now don't even know what an emulsion tube is.
Chopper, the 1850's are as you say, a "generic" carb with "universal" calibration. For your 2-4V application, you need to reduce the power curcut by about 40-50%, and keep the jetting where it is to reduce the over-rich condition. The 1850's metering blocks are not very sophisticated in their set-up, but that will be an easy first step.
With the heavy secondary springs, are the carbs even opening during acceleration? We usually work with accelerator pump volume&timing, power valves, linkage adjustment, float setting, and moderate springs to adjust for "bog".
We have used the 450 vacuum secondary carbs on very mild engines, but not the double pumpers. Have any of you that are using the double pumper 450 carbs on hotter engines ever monitored engine vacuum at WOT at higher rpm's? I would be really interested in what you have for engine vacuum at say 5000-6500rpm.
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