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Old 08-27-2011, 10:53 PM
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Originally Posted by L79vette
Each top is completely divided in half. There are two tops, each of which has completely separated right and left plenums. So there are four plenums all together. Using small-block Chevy cyinder numbering, there is one plenum for #1 & #3, one for #2 & #4, one for #5 & #7, and one for #6 & #8.

When you start thinking about the firing order, you quickly see a big problem we had to engineer around. #5 and #7 fire right next to each other in the firing order. The other pairs have a pattern like bang-rest-rest-bang-rest-rest-rest-rest (for #1 & #3). So you get this weird induction, rest-two-cycles, induction, rest-four-cycles pattern. For some pairs the cylinder under the primary venturi goes after four rest cycles, while for the #6 & #8 pair it is the cylinder under the secondary. So we had to do some major work on the carburetors to get even fueling everywhere. We have screw-in air bleeds, and each venturi has jetting and air bleeds tuned separately. We have 8 wide-band oxygen sensors on the dyno so we can graph what each cylinder is seeing for air-fuel all the way through the pull.

I see them now.... I guess I was in the sun to long today..
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