Engine Induction System Patent Text - Dual Plenum Intake & Throttle Staging (2001)

This is page 16 of the Summer 2001 issue of a newsletter ("S H & Tell"), reprinting the concluding portion of a patent describing an induction system for an internal combustion engine. The text explains how staged opening of throttle valves (referenced as valves 64 and 77) at engine speeds n1 and n2 reduces the 'valley' in the engine's torque curve, producing improved torque curves labeled P1, P2, and P3 in the patent's FIG. 6. It then describes an alternate embodiment (FIG. 4) using dual plenum chambers (45 and 46) with high-speed intake passages and longer intake passages (81 and 82) serving cylinder groups 15/16/17 and 18/19/21 respectively, where passage length is varied by curving passages or changing their plenum entry location. The page concludes with the patent's claims section, listing claims 1 through 6 covering an induction system with variable volume chambers, a plenum chamber, first and second intake passages, a flow control valve responsive to engine running characteristics, first and second atmospheric air inlets, and throttle valve means, with dependent claims covering separate throttle valves, different longitudinal inlet locations, and different effective cross-sectional areas of the air inlets. A reader learns the technical rationale for staged multi-throttle, dual-plenum variable-length intake systems and the exact patent claim language.