Abstract: A method for operating an internal combustion engine includes moving a piston downward from a top dead center position to a bottom dead center position expanding a combustion chamber in an intake stroke, dispensing a first portion of fuel into the combustion chamber, subsequent to moving the piston downward in the intake stroke, moving the piston upward in the vertical direction compressing the combustion chamber in a compression stroke, subsequent to moving the piston upward in the compression stroke, moving the piston downward in the vertical direction in an expansion stroke, while moving the piston downward in the vertical direction in the expansion stroke, dispensing a second portion of fuel into the combustion chamber, and while moving the piston downward in the expansion stroke, igniting at least a part of the first portion of fuel and the second portion of fuel.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of passing a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

Abstract: A method for operating an internal combustion engine includes moving a piston downward from a top dead center position to a bottom dead center position expanding a combustion chamber in an intake stroke, dispensing a first portion of fuel into the combustion chamber, subsequent to moving the piston downward in the intake stroke, moving the piston upward in the vertical direction compressing the combustion chamber in a compression stroke, subsequent to moving the piston upward in the compression stroke, moving the piston downward in the vertical direction in an expansion stroke, while moving the piston downward in the vertical direction in the expansion stroke, dispensing a second portion of fuel into the combustion chamber, and while moving the piston downward in the expansion stroke, igniting at least a part of the first portion of fuel and the second portion of fuel.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method including one or more of the steps of passing a first fuel and a second fuel into a combustion chamber of an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate the piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The engine cylinder may include a cylinder head and cylinder sidewalls, and the combustion chamber may be defined at least partially by the cylinder head, the cylinder sidewalls, and the piston. The first fuel may include a greater octane rating than the second fuel. The combustion chamber may include an end gas region and a central region, the central region more near to the spark plug than the end gas region.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of passing a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of injecting a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method including one or more of the steps of passing a first fuel and a second fuel into a combustion chamber of an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate the piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The engine cylinder may include a cylinder head and cylinder sidewalls, and the combustion chamber may be defined at least partially by the cylinder head, the cylinder sidewalls, and the piston. The first fuel may include a greater octane rating than the second fuel. The combustion chamber may include an end gas region and a central region, the central region more near to the spark plug than the end gas region.

Abstract: According to one or more embodiments, an internal combustion engine may be operated by a method which includes one or more of injecting a first fuel and a second fuel into an engine cylinder to form a fuel mixture, and combusting the fuel mixture with a spark plug to translate a piston housed in the engine cylinder and rotate a crank shaft coupled to the piston. The first fuel may comprise a greater octane rating than the second fuel. A target CA50 may correspond to a minimum in specific fuel consumption of the fuel mixture. The spark plug may initiate combustion at a time such that the internal combustion engine operates with an operational CA50 that is within 20 degrees of the target CA50.

Abstract: The present invention relates to an internal-combustion engine comprising at least one cylinder (10, 12, 14, 16) including intake means with an intake valve (22), exhaust means with an exhaust valve (32) and control means (40, 42) for controlling opening/closing of the valves, said control means comprising drive means (44) and means (56) intended for motion and load transmission between said control means and the valve to be controlled. According to the invention, motion and load transmission means (56) comprise a rocker arm (58) with at least two rockers (72, 74) disengageable from a pad (62) controlling the motion of said valve.

Abstract: The present invention relates to an internal-combustion engine comprising at least one cylinder (10, 12, 14, 16) including intake means with an intake valve (22), exhaust means with an exhaust valve (32) and control means (40, 42) for controlling opening/closing of the valves, said control means comprising drive means (44) and means (56) intended for motion and load transmission between said control means and the valve to be controlled. According to the invention, motion and load transmission means (56) comprise a rocker arm (58) with at least two rockers (72, 74) disengageable from a pad (62) controlling the motion of said valve.