An internal combustion engine system includes a compressor arranged to compress air, at least one combustor, at least one of the at least one combustor being arranged to receive the compressed air, and an exhaust treatment device arranged to process exhaust gases produced by at least one of the at least one combustor, a heat exchanger arranged to receive the compressed air from the compressor before it reaches the at least one of the at least one combustor, and wherein the heat exchanger is arranged to transfer heat from the compressed air to the exhaust treatment device.

An internal combustion engine system includes at least one combustor, a compressor arranged to compress air, an air guide arranged to guide compressed air from the compressor to at least one of the at least one combustor, an expander arranged to expand exhaust gases from at least one of the at least one combustor and to extract energy from the expanded exhaust gases, and an exhaust guide arranged to guide exhaust gases from at least one of the at least one combustor to the expander, wherein the exhaust guide is at least partly integrated with the air guide.

An internal combustion engine system includes at least one combustor, a compressor arranged to compress air, an air guide arranged to guide compressed air from the compressor to at least one of the at least one combustor, an expander arranged to expand exhaust gases from at least one of the at least one combustor and to extract energy from the expanded exhaust gases, and an exhaust guide arranged to guide exhaust gases from at least one of the at least one combustor to the expander, wherein the exhaust guide is at least partly integrated with the air guide.

An internal combustion engine system includes a combustor arranged to repetitively receive air and fuel, combust the received air and fuel, and expand the combusted air and fuel, an expander including a cylinder and a piston arranged to reciprocate in the cylinder, the piston being connected to a crankshaft of the engine system, and an exhaust guide arranged to guide exhaust gases from the combustor to the expander, wherein the system is arranged to provide an injection of fuel into the exhaust guide and/or arranged to provide an injection of fuel into the combustor after a combustion in the combustor and before a reception of air and fuel in the combustor for a subsequent combustion.

A split-cycle internal combustion engine includes a variable displacement compressor having two or more cylinders, an adjustment mechanism for varying the displacement volume of the compressor and possibly the phase between the compressor and the motor, and a rotary motor having two or more expansion chambers. A passage valve system located between the compressor and the motor transfers working fluid and combustion exhaust products, and, in addition, mechanically and thermally isolates the compressor from the high pressures and temperatures present in the motor.

A split-cycle internal combustion engine includes a variable displacement compressor having two or more cylinders, an adjustment mechanism for varying the displacement volume of the compressor and possibly the phase between the compressor and the motor, and a rotary motor having two or more expansion chambers. A passage valve system located between the compressor and the motor transfers working fluid and combustion exhaust products, and, in addition, mechanically and thermally isolates the compressor from the high pressures and temperatures present in the motor.

An internal combustion engine system includes at least one combustor, and a first expander arranged to receive exhaust gases from at least one of the at least one combustor, and to expand and extract energy from the exhaust gases, wherein the system includes a second expander arranged to receive exhaust gases from the first expander, and to expand and extract energy from the exhaust gases.

A two-stroke engine includes a crankcase. A power cylinder extends from the crankcase. The power cylinder selectively fluidly communicates with the crankcase to scavenge the power cylinder. A power piston is reciprocably disposed in the power cylinder. A compressor cylinder extends from the crankcase. The compressor cylinder selectively fluidly communicates with the power cylinder to introduce a pressurized air/fuel mixture into the power cylinder. A compressor piston is reciprocably disposed in the compressor cylinder.

A split-cycle engine includes a compression cylinder having a first volume for a first working fluid and a second volume for a second working fluid, the first volume and second volume being separated by the compression piston, an expansion cylinder having a first volume for the first working fluid and a second volume for the second working fluid, the first volume and second volume being separated by the expansion piston, and a fluid coupling between the second volume of the compression cylinder and the second volume of the expansion cylinder, wherein the two second volumes and the fluid coupling provide a closed volume for the second working fluid, wherein the fluid coupling includes a regenerator arranged such that the two second volumes are thermally decoupled.

A split-cycle engine includes a compression cylinder having a first volume for a first working fluid and a second volume for a second working fluid, the first volume and second volume being separated by the compression piston, an expansion cylinder having a first volume for the first working fluid and a second volume for the second working fluid, the first volume and second volume being separated by the expansion piston, and a fluid coupling between the second volume of the compression cylinder and the second volume of the expansion cylinder, wherein the two second volumes and the fluid coupling provide a closed volume for the second working fluid, wherein the fluid coupling includes a regenerator arranged such that the two second volumes are thermally decoupled.