Indirect variable valve actuation for an internal combustion engine

An internal combustion engine that operates on an engine cycle, comprising:

• multiple engine cylinders, each cylinder including first and second intake ports;
• first intake runners providing passages through which intake gas enters the first intake port of each respective cylinder;
• second intake runners providing passages through which intake gas enters the second intake port of each respective cylinder;
• first intake valves for opening and closing the first intake port of each respective cylinder;
• second intake valves for opening and closing the second intake port of each respective cylinder;
• a plenum having an inlet through which intake gas enters the plenum, and first and second outlets through which intake gas exits the plenum;
• a first resonator communicating with the first outlet and the first intake runner of each respective cylinder and producing in the first intake runner first pressure pulses of intake gas having a varying cyclic amplitude;
• a second resonator communicating with the second outlet and with the second intake runner of each respective cylinder and producing in the second intake runner second pressure pulses of intake gas having a varying cyclic amplitude that is out of phase with the first cyclic pressure pulses;
• and
• first flaps, each first flap located in a first intake runner upstream from, and in series with a respective first intake valve, having first and second positional states that vary during each engine cycle, the first state opening the first intake runner passage to permit the first pressure pulses to enter the respective first intake port when an amplitude of the first pressure pulses reaches a predetermined magnitude, the second state at least partially closing the respective first intake runner passage to limit the flow rate of intake gas from the respective cylinder through the respective first intake port, wherein said first and second positional states vary synchronously with each engine cycle.

An internal combustion engine that operates on an engine cycle, comprising:

• an engine cylinder including an intake port and an exhaust port;
• an intake runner providing a passage through which intake gas enters the cylinder through the intake port;
• an exhaust runner providing a passage through which exhaust gas exits the cylinder through the exhaust port;
• a flap located in one of the intake runner or exhaust runner, having first and second positional states that vary during each engine cycle, the first state opening the respective runner passage, the second state at least partially closing the respective runner passage, wherein said first and second positional states vary synchronously with each engine cycle.

A system for controlling an engine comprising:

• an internal combustion engine that operates on an engine cycle, the engine including a cylinder, an intake port communicating with a source of intake air, and an engine intake valve for opening and closing communication between the cylinder and the intake port;
• a flap operatively arranged in series with and located upstream from the engine intake valve;
• sensors producing signals representing operating parameters;
• a controller operatively connected to the sensors, determining with reference to an operating parameter points during the engine cycle when a future opening and a future closing of the engine intake valve will occur, opening the flap before the engine intake valve opens during the current engine cycle, and in responsive to said determination closing the flap before the engine valve closes such that a pressure pulse from the air source is retained in the cylinder, wherein said opening and closing of said engine intake valve varies synchronously with each engine cycle.