A method and system for actuating an internal combustion engine exhaust
valve to provide compression release actuation during an engine braking
mode of engine operation and early exhaust valve opening actuation during
a positive power mode of engine operation is disclosed. The system may
include a first cam having a compression release lobe and an early
exhaust valve opening lobe connected to a hydraulic lost motion system
including a first rocker arm. A hydraulically actuated piston may be
selectively extended from the hydraulic lost motion system to provide the
exhaust valve with compression release actuation or early exhaust valve
opening actuation. The hydraulically actuated piston may be provided as a
slave piston in a master-slave piston circuit in a fixed housing, or
alternatively, as a hydraulic piston slidably disposed in a rocker arm.
The method and system may further provide exhaust gas recirculation
and/or brake gas recirculation in combination with compression release
actuation and early exhaust valve opening actuation.