Methods and systems for providing engine braking for a two stroke diesel engine are described. In one example, a flow through a mechanically driven supercharger is adjusted to provide engine braking for a two stroke diesel engine when engine braking is requested. The level or amount of engine braking may be adjusted via increasing or decreasing flow through the mechanically driven supercharger.

Methods and systems for providing engine braking for a two stroke diesel engine are described. In one example, a flow through a mechanically driven supercharger is adjusted to provide engine braking for a two stroke diesel engine when engine braking is requested. The level or amount of engine braking may be adjusted via increasing or decreasing flow through the mechanically driven supercharger.

Methods and systems for providing engine braking for a two stroke diesel engine are described. In one example, a flow through a mechanically driven supercharger is adjusted to provide engine braking for a two stroke diesel engine when engine braking is requested. The level or amount of engine braking may be adjusted via increasing or decreasing flow through the mechanically driven supercharger.

A camshaft assembly for an internal combustion engine of a vehicle and method of operating the camshaft assembly to enhance engine braking performance through selective activation of a cam lobe having a brake gas recirculation contour. The camshaft assembly comprises an exhaust camshaft and a lobe pack on the exhaust camshaft, with the lobe pack including a plurality of cam lobes. At least one cam lobe of the plurality of cam lobes includes a brake gas recirculation cam contour having an exhaust stroke projection and a combustion stroke projection. The method switches to the cam lobe including the brake gas recirculation profile when certain criteria indicate that an engine braking mode is to be activated.

A valve train assembly configured to selectively open and close intake and exhaust valves associated with cylinders of an internal combustion engine comprises an intake rocker arm assembly, an intake cam assembly, a first axial shifting cam assembly and a second axial shifting cam assembly. The intake rocker arm assembly can have a plurality of intake rocker arms. The intake cam assembly can be associated with each of the cylinders and can have three distinct cam profiles including a first cam profile, a second cam profile and a third cam profile. The first axial shifting cam assembly can operate independently from the second axial shifting cam assembly to provide three distinct valve lift profiles on the first grouping of cylinders and three distinct valve lift profiles on the second grouping of cylinders.

An engine system and method of operation therefor are provided. The system is a two-stroke internal combustion engine having an exhaust valve assembly that controls the exhaust cycle relative to crankshaft timing. The exhaust valve assembly is positioned between exhaust port and an exhaust pipe. The exhaust valve assembly comprises a rotary exhaust valve and valve phasing assembly. The rotary exhaust valve comprises a valve body defining a valve void therethrough. The use of the rotary exhaust valve allows for alteration or calibration of the fixed time and location at which the intake port and exhaust port are opened and closed by the piston with respect to the respective engine cycle. Notably, while still uncovered by the piston, the exhaust port may be closed due to full misalignment of the valve void and the exhaust port, while the intake port remains open, allowing for cylinder charging.

Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.

Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.

A method of raising exhaust gas temperatures of a two-cycle uniflow scavenged engine at lower loads. At lower loads, the exhaust valves are activated with a frequency that is less frequent than every engine cycle. This retains exhaust within the cylinder for one or more cycles, and when the exhaust valves are again activated, the exhaust temperature will be elevated. For engines having a means for controlling intake manifold pressure, such as a compressor having variable speed or a means for bleeding off compressor output, intake manifold pressure can be reduced at low loads, which also has the effect of elevating exhaust temperatures.

A rocker arm mechanism of an engine, a system and a method for two-stroke engine brake are provided. The rocker arm mechanism includes a first rocker arm, a second rocker arm and a connection mechanism. One end of the first rocker arm and one end of the second rocker arm is rotatably connected to a shaft, the other end of the first rocker arm is close to a valve of the engine, while the other end of the second rocker arm is close to a cam. The connection mechanism includes a connecting piston and a linkage mechanism. The connecting piston is disposed in the first rocker arm or the second rocker arm, the linkage mechanism is rotatably connected to one end of the connecting piston. The rocker arm mechanism may be used for engine cylinder deactivation and engine brake.