Internal combustion engine with intake manifold plenum and method of use

A spark-ignition combustion engine comprising:

• a plurality of combustion chambers;
• an intake manifold coupled to the plurality of combustion chambers via a plurality of intake manifold branches;
• a one-way valve positioned in each of the plurality of intake manifold branches;
• a plurality of intake valves for modulating flow of a fuel-air mixture into and out of the combustion chambers, each combustion chamber having at least one intake valve;
• a plurality of fixed volume plenum chambers connected to each of the intake manifold branches, wherein each plenum chamber is positioned downstream from the one-way valve and wherein each combustion chamber has an associated plenum chamber;
• and
• a plenum valve in each of the plurality of plenum chambers for controlling the flow of the fuel-air mixture between the manifold and each respective plenum chamber.

A method of controlling the effective compression ratio of a combustion engine through the use of a plenum located in the intake manifold of an engine, the method comprising the steps of:

• introducing a fuel-air mixture into an intake manifold, the fuel-air mixture passing through a one-way valve into the intake manifold;
• introducing the fuel-air mixture into a combustion chamber via an intake valve during the intake stroke;
• compressing the fuel-air mixture in the combustion chamber such that a portion of the fuel-air mixture exits the combustion chamber and enters the intake manifold and plenum during the compression stroke;
• and
• controlling the amount of fuel-air mixture entering the plenum by adjusting a plenum valve located between the plenum and the intake valve.

A method of controlling the power output of a four stroke combustion engine by using a plenum located in the intake manifold, the method comprising the steps of:

• introducing a fuel-air mixture into a combustion chamber, the fuel air mixture passing through a one-way valve in the intake manifold prior to entering the combustion chamber via an intake valve;
• and
• storing a pressurized charge of the fuel-air mixture within the manifold and plenum, the pressurized charge of fuel-air mixture exiting the combusting chamber and entering the plenum during the compression stroke of the engine;
• reintroducing the pressurized charge of fuel-air mixture into the combustion chamber on a next intake stroke;
• and
• controlling the amount of pressurized fuel-air mixture stored within the plenum for each compression stroke by adjustment of a plenum valve located between the plenum and the intake valve.

A method of operating a combustion engine by using a plenum located in the intake manifold, the method comprising the steps of:

• opening an intake valve for the intake stroke of the engine;
• introducing a fuel-air mixture into the combustion chamber;
• compressing the fuel-air mixture during the compression stroke, wherein at least a portion of the fuel-air mixture exits the combustion chamber and enters the manifold and plenum through the open intake valve and a plenum valve located between the plenum and the intake valve;
• closing the intake valve during or at the end of the compression stroke, wherein when the intake valve closes, a pressurized fuel-air mixture is stored within the manifold and plenum, the fuel-air mixture contained therein by a one-way valve and the closed intake valve;
• combusting the fuel-air mixture during a combustion stroke;
• exhausting the combusted fuel-air mixture through an exhaust valve during an exhaust stroke;
• opening the intake valve for the next intake stroke;
• and
• introducing a fuel-air mixture containing the pressurized fuel-air mixture stored in the plenum and manifold into the combustion chamber.