Manifold for internal combustion engines having independent runners, a two-plane layout, and independent plenums

摘要

Independent runners of a multiple runner manifold feed from two independent plenums. Alternate runners, in the sense of engine firing order, feed from alternate of the plenums. The physical separation of the plenums attenuates intercylinder interference. Long runners of small cross section provide large mixture quantity and high mixture velocity for good torque. Runner cross-sectional area also is determined by that mixture velocity at which maximum torque occurs. The runners are tuned to the first harmonic to correspond to optimum torque. The runners of one plenum pass over the runners of the other so that runner geometry is simple.