Abstract: A lower manifold for a V-style internal combustion engine comprising at least three shells: a top shell for mating with an upper manifold; a left shell for mating with a left engine head; and a right shell for mating with a right engine head. The three shells are formed independently by injection molding and are joined as by vibration welding when aligned in a welding jig. The molds for the left and right shells are formed such that the seal ring groove has a rectangular cross-section having sidewalls perpendicular to the lower shell surface because each left and right shell has its own draft angle preferably perpendicular to its lower shell surface. The method and apparatus of the invention permits runner cross-sections to be significantly rounded, which improves air flow characteristics of the runners.

Abstract: A lower manifold for a V-style internal combustion engine comprising at least three shells: a top shell for mating with an upper manifold; a left shell for mating with a left engine head; and a right shell for mating with a right engine head. The three shells are formed independently by injection molding and are joined as by vibration welding when aligned in a welding jig. The molds for the left and right shells are formed such that the seal ring groove has a rectangular cross-section having sidewalls perpendicular to the lower shell surface because each left and right shell has its own draft angle preferably perpendicular to its lower shell surface. The method and apparatus of the invention permits runner cross-sections to be significantly rounded, which improves air flow characteristics of the runners.

Abstract: A worm gear drive actuator having an output gear for controlling movement of a component between a default position and an activation position. The actuator includes a spring return connected to a return gear mounted in meshing engagement with a spur gear coaxially mounted to one end of the worm. As the worm is driven by a motor to rotate the output gear and thus the component to the activation direction, the spring turns and accumulates a torsional load. When the motor is deactivated, the spring releases its torsional load which rotates the return gear, spur gear, worm and output gear in the opposite direction which returns the component to its default position.

Abstract: A tumble control valve for an intake manifold of an engine which eliminates or substantially reduces air leakage between the bottom and sides of the valve blade through a selected rotational segment of the blade as it moves from the closed position toward the open position. The sealed area is maintained by contouring the inner cavity wall to track the arc defined by the bottom edge of the rotating blade. In other embodiments, a flexible flange or wedge-shaped element is attached to the blade to engage the inner cavity wall through the selected rotational segment. In another aspect of the invention, air flow pressure is maintained and tumble is optimized compared to rotational movement of the blade by contouring the top wall surface to track the arc defined by the rotating upper edge of the blade.

Abstract: In a throttle body fuel injection assembly, the rotor of a throttle position sensor is mounted directly on the throttle shaft and the sensor housing is supported on the rotor, thereby providing a compact sensor construction. A spring in the sensor tends to impart relative rotation between the rotor and the housing, biasing the housing toward engagement with the throttle body. With this invention, the housing rotates with the rotor away from engagement with the throttle body if the spring does not impart relative rotation between the housing and the rotor.