A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

The invention provides an internal combustion engine system (1) comprisingat least one combustor (3), anda first expander (4) arranged to receive exhaust gases from at least one of the at least one combustor (3), and to expand and extract energy from the exhaust gases, characterized in that the system comprises a second expander (5) arranged to receive exhaust gases from the first expander (4), and to expand and extract energy from the exhaust gases.

The invention provides an internal combustion engine system (1) comprisingat least one combustor (3), anda first expander (4) arranged to receive exhaust gases from at least one of the at least one combustor (3), and to expand and extract energy from the exhaust gases, characterized in that the system comprises a second expander (5) arranged to receive exhaust gases from the first expander (4), and to expand and extract energy from the exhaust gases.

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.

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 piston arrangement for an engine is provided and includes a crankshaft located within a crank case and a primary piston located within a first cylinder and interconnected to the crankshaft by a first drive rod for converting reciprocating motion of the primary piston within the first cylinder driven by combustion occurring within the first cylinder into rotational motion of the crankshaft. The arrangement also includes a pumping piston located within a second cylinder and interconnected to the crankshaft by a second drive rod for converting the rotational motion of the crankshaft into reciprocating motion of the pumping piston within the second cylinder. The pumping piston is located between the primary piston and the crank case and seals the first and second cylinders from the crankcase. A stepped-piston and a two-stroke engine are also disclosed.

A piston arrangement for an engine is provided and includes a crankshaft located within a crank case and a primary piston located within a first cylinder and interconnected to the crankshaft by a first drive rod for converting reciprocating motion of the primary piston within the first cylinder driven by combustion occurring within the first cylinder into rotational motion of the crankshaft. The arrangement also includes a pumping piston located within a second cylinder and interconnected to the crankshaft by a second drive rod for converting the rotational motion of the crankshaft into reciprocating motion of the pumping piston within the second cylinder. The pumping piston is located between the primary piston and the crank case and seals the first and second cylinders from the crankcase. A stepped-piston and a two-stroke engine are also disclosed.

A liquid coolant injector for injecting a liquid coolant into a cylinder of a split cycle engine, wherein the liquid coolant has been condensed into a liquid phase via a refrigeration process, the injector comprising, a thermally insulating housing, a liquid coolant inlet, a liquid coolant outlet in fluid communication with the liquid coolant inlet via a liquid coolant flow path wherein the liquid coolant flow path extends through the thermally insulating housing, the thermally insulating housing configured to inhibit vaporisation of the liquid coolant within the liquid coolant flow path, a valve closure member, moveable between a first position in which the valve closure member blocks the liquid coolant flow path and a second position in which the liquid coolant may flow from the liquid coolant inlet to the liquid coolant outlet, and, a driver operable to move the valve closure member between the first and second position in response to a control signal.