Abstract: Adjacent expansible chambers of an engine are provided with an intake runner set employing at least three runner passages conducting the working fluid from a common plenum to the expansible chambers, with at least one of the runners only serving one of the expansible chambers, at least another of the runners serving only the other expansible chamber, and at least still another of the runners commonly serving both of the expansible chambers. Preferably, a flow control is provided for one or more of the runners, preferably the common runner to manually or automatically control the flow of fluid through the common runner. Thereby, the runners for the expansible chambers may be adjusted in effective cross sectional area for tuned efficiency at different speeds. Preferably, such runners extend through the intake manifold and head ports without communication throughout their extent. The partitions forming the runners may be removable so that others of different shape or location may be substituted.

Abstract: Adjacent expansible chambers of an engine are provided with an intake runner set employing at least three runner passages conducting the working fluid from a common plenum to the expansible chambers, with at least one of the runners only serving one of the expansible chambers, at least another of the runners serving only the other expansible chamber, and at least still another of the runners commonly serving both of the expansible chambers. Preferably, a flow control is provided for one or more of the runners, preferably the common runner to manually or automatically control the flow of fluid through the common runner. Thereby, the runners for the expansible chambers may be adjusted in effective cross sectional area for tuned efficiency at different speeds. Preferably, such runners extend through the intake manifold and head ports without communication throughout their extent. The partitions forming the runners may be removable so that others of different shape or location may be substituted.

Abstract: The runners of the intake manifold between the fuel-air mixture device and the valve ports of the head of an internal combustion enginer are tuneable to a particular engine speed range automatically by means of a pivotal mount for a wall portion of the runner in combination with a spring urging the runner wall portion towards the central axis of the runner to correspondingly decrease and increase the flow through cross sectional area along the runner in response to a decrease and increase, respectively, of the engine speed. The spring force may be separately adjustable.

Abstract: Adjacent expansible chambers of an engine are provided with an intake runner set employing at least three runner passages conducting the working fluid from a common plenum to the expansible chambers, with at least one of the runners only serving one of the expansible chambers, at least another of the runners serving only the other expansible chamber, and at least still another of the runners commonly serving both of the expansible chambers. Preferably, a flow control is provided for one or more of the runners, preferably the common runner to manually or automatically control the flow of fluid through the common runner. Thereby, the runners for the expansible chambers may be adjusted in effective cross sectional area for tuned efficiency at different speeds. Preferably, such runners extend through the intake manifold and head ports without communication throughout their extent.

Abstract: The runners of the intake manifold between the fuel-air mixture device and the valve ports of the head of an internal combustion engine are tuneable to a particular engine and/or RPM range either manually or automatically by moving at least one wall of each runner inwardly and outwardly to correspondingly decrease and increase the flow through cross-sectional area along the runner. Manual adjustments may be made for particular running conditions or engine component combinations, and automatic adjustments may be made in correspondence with changes in engine speed during operation by vacuum controls, throttle linkage, or electrical controls, for example.