Abstract: A system for controlling pressure in a container, for example the carburetor of an internal combustion engine, from a periodic acoustic source, for example the intake or exhuast of the engine or a selected engine component where the alternating pressure varies only slightly according to engine speed where it is desired to modify the slope of a fuel richness curve over a wide operating range. The system is characterized in that it comprises a conduit connecting the container chamber to the acoustic source, the pressure losses being different according to the direction of flow in the conduit.

Abstract: An improvement in internal combustion engines for suppressing faulty carburetion caused by acoustic vibrations in the engine is provided by an acoustic resonator communicated with the intake manifold between the valves and the carburetor thereof. The resonator consists of an enclosed chamber of preselected volume connected to the intake manifold by at least one tubular conduit.

Abstract: An improvement in internal combustion engines for suppressing faulty carburetion caused by acoustic vibrations in the engine is provided by an acoustic resonator communicated with the intake manifold between the valves and the carburetor thereof. The resonator consists of an enclosed chamber of preselected volume connected to the intake manifold by at least one tubular conduit.