An engine unit controller (EUC) in connection with a hybrid opposed piston engine can receive real-time movement data of a crankshaft via a crank position sensor. It can simultaneously receive current data of an electric motor that partially controls the crankshaft. With the known engine constants, the EUC can determine instantaneous combustion pressure data based on the movement data and the current data. Such combustion pressure data can be used to optimize the engine's performance in real-time.

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.

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.

A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

A method of operating a two-stroke cycle, opposed-piston engine comprising a pumping device coupled to pump air to cylinders of the engine through a charge air cooler and an aftertreatment system of thermally-activated devices coupled to receive exhaust from the cylinders by which a thermal state of the exhaust sufficient to sustain thermal activation of one or more of the aftertreatment system devices may be maintained during a deceleration or motoring condition of operation by reducing the mass airflow to the engine.

An engine and method for achieving superior operational benefits by application of the General Cycle for heat engines. A two-stroke internal combustion engine having an Atkinson ratio A and a compression ratio R.sub.C, the compression ratio having a value in the range from 19 to 30, and an Atkinson ratio selected such that the product of Atkinson ratio and compression ratio is near to and generally greater than 36. The best values of this product, AR.sub.C, vary slightly with the choice of compression ratio according to the following relationship:
AR.sub.C≥36.33+8788e.sup.−0.375Rc. The engine includes a conventional exhaust valve and may include a high ratio of stroke length to bore, or may be of an opposed piston construction.

An engine and method for achieving superior operational benefits by application of the General Cycle for heat engines. A two-stroke internal combustion engine having an Atkinson ratio A and a compression ratio R.sub.C, the compression ratio having a value in the range from 19 to 30, and an Atkinson ratio selected such that the product of Atkinson ratio and compression ratio is near to and generally greater than 36. The best values of this product, AR.sub.C, vary slightly with the choice of compression ratio according to the following relationship:
AR.sub.C≥36.33+8788e.sup.−0.375Rc. The engine includes a conventional exhaust valve and may include a high ratio of stroke length to bore, or may be of an opposed piston construction.

An opposed-piston engine includes an electronic sensor located in a charge air channel, at position between an outlet of a charge air cooler and an air intake component that distributes charge air to cylinder intake ports of the engine. The electronic sensor is disposed to measure a rate of mass airflow between the outlet of the charge air cooler and the intake component and generate electronic signals indicative of the rate of mass airflow from the charge air cooler. A control mechanization of the opposed-piston engine is electrically connected to the electronic sensor for controlling air handling devices, fuel provisioning devices, and/or EGR devices in response to the electronic signals.

An opposed-piston engine includes an electronic sensor located in a charge air channel, at position between an outlet of a charge air cooler and an air intake component that distributes charge air to cylinder intake ports of the engine. The electronic sensor is disposed to measure a rate of mass airflow between the outlet of the charge air cooler and the intake component and generate electronic signals indicative of the rate of mass airflow from the charge air cooler. A control mechanization of the opposed-piston engine is electrically connected to the electronic sensor for controlling air handling devices, fuel provisioning devices, and/or EGR devices in response to the electronic signals.

An engine unit controller (EUC) in connection with a hybrid opposed piston engine can receive real-time movement data of a crankshaft via a crank position sensor. It can simultaneously receive current data of an electric motor that partially controls the crankshaft. With the known engine constants, the EUC can determine instantaneous combustion pressure data based on the movement data and the current data. Such combustion pressure data can be used to optimize the engine's performance in real-time.