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.

An opposed piston engine is provided. The engine includes a mechanism enabling adjustment of a compression ratio of the engine.

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 configuration for a uniflow-scavenged, opposed-piston engine reduces exhaust cross-talk caused by mass flow between cylinders resulting from one cylinder having an open exhaust port during scavenging and/or charging while an adjacent cylinder is undergoing blowdown. Some configurations include a wall or other barrier feature between cylinders that are adjacent to each other and fire one after the other. Additionally, or alternatively, some engine configurations include cylinders with intake and exhaust ports sized so that there is an overlap in crank angle of two or more cylinders having open exhaust ports of about 65 crank angle degrees or less.

A piston construction with an end surface is equipped with a pattern of insulating cavities embedded in an upper end of the piston, between the end surface and interior portions of the piston that are cooled by circulating liquid coolant.

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.

An inventive opposed piston engine is provided. The inventive engine includes an inventive mechanism that enables adjustment of a compression ratio of the engine.

An inventive opposed piston engine is provided. The inventive engine includes an inventive mechanism that enables adjustment of a compression ratio of the engine.

A crank and connecting rod mechanism, comprising at least one piston, which reciprocates within at least one cylinder, comprising: at least one connecting rod, comprising: a piston end pivotally connected to the at least one piston, a crank end; at least one gear set, comprising: a crankpin, the crank end pivotally connected to the crankpin; a crank gear; a crank gear shaft, the crank gear rotatably mounted on the crank gear shaft, the crankpin located between centerline of the crank gear shaft and radius of the pitch circle of the crank gear; a stationary gear, the crank gear meshing with the stationary gear, the crank end driving the crankpin, which drives the crank gear and the crank gear shaft about the stationary gear; the crank pin and the crank end rotating about the stationary gear and following the path of a roulette of a centered trochoid about the stationary gear.