Abstract: Engines and processes for their operation include a compressor cylinder, at least one power cylinder, and an expander cylinder. The outlet of the compressor cylinder is fed to the inlet of a power cylinder, and the outlet of the power cylinder is fed to the expander cylinder. The compressor cylinder and the expander cylinder are operated in two-stroke fashion, and the power cylinder is operated in four-stroke fashion, all of which cylinders share a common crankshaft. Heat may be recuperated from the exhaust gas and directed to the inlet gas of the power cylinder, increasing overall efficiency.

Abstract: A method to manage and control engine operation includes injecting an initial mass of fuel into a combustion chamber to form a combustion charge, monitoring combustion and injecting a main mass of fuel into the combustion chamber substantially coincident with a start of combustion of the combustion charge.

Abstract: A method for controlling combustion in a direct-injection diesel engine includes monitoring a crankshaft rotational position of a cylinder of the engine, monitoring an engine load, determining an intake stroke within the cylinder based upon the crankshaft rotational position, and when the engine load is less than a threshold engine load, opening an exhaust valve for the cylinder during a portion of the intake stroke.

Abstract: An apparatus, system, and method are disclosed for efficiently operating an engine utilizing exhaust gas recirculation (EGR). The apparatus includes an exhaust manifold receiving exhaust gas from a first cylinder set, an EGR manifold receiving exhaust gas from a second cylinder set, and a passage comprising a variable restriction. The passage fluidly couples the exhaust manifold to the EGR manifold. The apparatus further includes a controller with modules for interpreting engine operating conditions and controlling actuators in response to the engine operating conditions.

Abstract: A method to manage and control engine operation includes injecting an initial mass of fuel into a combustion chamber to form a combustion charge, monitoring combustion and injecting a main mass of fuel into the combustion chamber substantially coincident with a start of combustion of the combustion charge.