Abstract: A system and method for controlling an internal combustion engine operable with a first cylinder firing frequency and a second cylinder firing frequency to reduce or eliminate transmission of torsional vibrations associated with the second cylinder firing frequency to reduce or eliminate constraints on reduced displacement mode operation using a closely coupled drive train component rotating in an opposite direction relative to rotating components of the engine. A close coupling device allows the inertia of the counter-rotating elements to reduce or eliminate the torque reaction of the drivetrain associated with acceleration and deceleration of the engine crankshaft in response to the second cylinder firing frequency in the reduced displacement mode.

Abstract: A method adjusts a torque differential between firing cylinders based on engine speed such that greater torque differentials are provided at higher engine speeds. Further, the torque differential may be adjusted based on the firing pattern of the cylinders.

Abstract: A dual crankshaft internal combustion engine is symmetrically constructed to form a perfectly balanced engine assembly. A first crankshaft, having a first end, a second end, and being formed of a shape and with a torsional flexibility, is housed within a cylinder block and connected to a first series of cooperating pistons and cylinders. A second crankshaft, having a first end and a second end, is formed of substantially the same shape as the first crankshaft and has substantially the same torsional flexibility as the first crankshaft. The second crankshaft is also housed within the cylinder block and connected to a second series of cooperating pistons and cylinders, while being positioned parallel to the first crankshaft, with the first end of the first crankshaft being positioned adjacent to the second end of the second crankshaft.

Abstract: A method of operating an internal combustion engine having a plurality of cylinders including at least a first cylinder and a second cylinder, the method comprising firing the first cylinder and the second cylinder in an alternating sequence; during a first mode, adjusting an operating parameter of the engine to produce a first difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; during a second mode, adjusting the operating parameter of the engine to produce a second difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; and performing the first mode at a higher engine speed than the second mode; wherein the first difference is greater than the second difference.

Abstract: Systems and methods for managing camshaft dynamic loads associated with actuation of a camshaft-driven auxiliary device in a multiple-cylinder internal combustion engine apply positive and negative torque to the camshaft in a phased relationship relative to actuation of the auxiliary device and optionally relative to actuation of intake or exhaust valves operated by the camshaft.

Abstract: A dual crankshaft internal combustion engine is symmetrically constructed to form a perfectly balanced engine assembly. A first crankshaft, having a first end, a second end, and being formed of a shape and with a torsional flexibility, is housed within a cylinder block and connected to a first series of cooperating pistons and cylinders. A second crankshaft, having a first end and a second end, is formed of substantially the same shape as the first crankshaft and has substantially the same torsional flexibility as the first crankshaft. The second crankshaft is also housed within the cylinder block and connected to a second series of cooperating pistons and cylinders, while being positioned parallel to the first crankshaft, with the first end of the first crankshaft being positioned adjacent to the second end of the second crankshaft.

Abstract: A method of operating an internal combustion engine having a plurality of cylinders including at least a first cylinder and a second cylinder, the method comprising firing the first cylinder and the second cylinder in an alternating sequence; during a first mode, adjusting an operating parameter of the engine to produce a first difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; during a second mode, adjusting the operating parameter of the engine to produce a second difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; and performing the first mode at a higher engine speed than the second mode; wherein the first difference is greater than the second difference.

Abstract: A method of operating an internal combustion engine having a plurality of cylinders including at least a first cylinder and a second cylinder, the method comprising firing the first cylinder and the second cylinder in an alternating sequence; during a first mode, adjusting an operating parameter of the engine to produce a first difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; during a second mode, adjusting the operating parameter of the engine to produce a second difference between an amount of torque produced by the firing of the first cylinder and an amount of torque produced by the firing of the second cylinder; and performing the first mode at a higher engine speed than the second mode; wherein the first difference is greater than the second difference.

Abstract: A system and method for controlling an internal combustion engine operable with a first cylinder firing frequency and a second cylinder firing frequency to reduce or eliminate transmission of torsional vibrations associated with the second cylinder firing frequency to reduce or eliminate constraints on reduced displacement mode operation using a closely coupled drive train component rotating in an opposite direction relative to rotating components of the engine. A close coupling device allows the inertia of the counter-rotating elements to reduce or eliminate the torque reaction of the drivetrain associated with acceleration and deceleration of the engine crankshaft in response to the second cylinder firing frequency in the reduced displacement mode.