In an opposed-piston engine which includes a catalytic aftertreatment device in its exhaust system an exhaust gas condition indicating a catalyst temperature of the aftertreatment device is monitored. When the catalyst temperature is near or below a light-off temperature, a catalyst light-off procedure is executed to elevate the temperature of the catalyst.

Control of fuel flow in a uniflow-scavenged, two-stroke cycle, opposed-piston engine includes limiting an amount of torque or fuel in response to a torque demand, based upon a comparison and a selection of fuel delivery options derived from a global airflow parameter and/or a trapped airflow parameter.

Control of fuel flow in a uniflow-scavenged, two-stroke cycle, opposed-piston engine includes limiting an amount of torque or fuel in response to a torque demand, based upon a comparison and a selection of fuel delivery options derived from a global airflow parameter and/or a trapped airflow parameter.

A two-stroke opposed piston internal combustion engine including a plurality of cylinders, each cylinder being provided with a first piston and a second piston adapted to perform opposed motions in the cylinder, each cylinder being provided with at least one intake port, a communication between an air intake arrangement and the cylinder via the intake port being dependent on the position of the first piston, each cylinder further being provided with at least one exhaust port, a communication between an exhaust guiding arrangement and the cylinder via the exhaust port being dependent on the position of the second piston, at least one of the cylinders being provided with an additional port and an additional port valve, a communication between the cylinder and an additional conduit externally of the cylinder, via the additional port, being controllable with the additional port valve, the air intake arrangement including at least one intake valve for selectively reducing or inhibiting air admittance to at least one of the cylinders.

A two-stroke opposed piston internal combustion engine including a plurality of cylinders, each cylinder being provided with a first piston and a second piston adapted to perform opposed motions in the cylinder, each cylinder being provided with at least one intake port, a communication between an air intake arrangement and the cylinder via the intake port being dependent on the position of the first piston, each cylinder further being provided with at least one exhaust port, a communication between an exhaust guiding arrangement and the cylinder via the exhaust port being dependent on the position of the second piston, at least one of the cylinders being provided with an additional port and an additional port valve, a communication between the cylinder and an additional conduit externally of the cylinder, via the additional port, being controllable with the additional port valve, the air intake arrangement including at least one intake valve for selectively reducing or inhibiting air admittance to at least one of the cylinders.

An internal combustion engine wherein at least two cylinders continuously communicate via the cylinder head and wherein the connecting rod in one cylinder is offset from the connecting rod in the second cylinder by a first angle between 8 and 12 degrees as measured from the crankshaft, and a camshaft having a second offset of one half of the first angle offset.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

An air handling arrangement in a two-stroke cycle, opposed-piston engine with uniflow scavenging and constructed for heavy-duty operation includes sequentially arranged turbochargers in series with a supercharger. In some aspects, the air handling system is equipped with an EGR channel.

An air handling arrangement in a two-stroke cycle, opposed-piston engine with uniflow scavenging and constructed for heavy-duty operation includes sequentially arranged turbochargers in series with a supercharger. In some aspects, the air handling system is equipped with an EGR channel.