Abstract: An improved engine retarder of the compression release type in which the exhaust valves are opened near the end of the compression stroke of the engine by a slave piston hydraulically interconnected with a master piston driven by an existing pushtube is provided. The improved engine retarder includes a second master piston interconnected hydraulically in parallel with the first master piston and driven by a separate existing pushtube whereby the timing of the compression release event may be regulated and the stress on the engine pushtubes may be reduced.

Abstract: An improved compression release engine braking system is provided for internal combustion engines having two exhaust valves associated with each cylinder. The slave piston of the compression release brake is relocated so as to register with one of the two exhaust valves and the crosshead assembly is modified so that actuation of the exhaust valve rocker arms will open both exhaust valves in the normal manner during the fueling mode of engine operation while the slave piston of the compression release brake will open only one of the exhaust valves during the engine braking mode of engine operation.

Abstract: Apparatus and method are provided for temporarily converting a turbocharged engine into a compressor that can provide compressed air for various uses, such as for pneumatic unloading of cargo. In a preferred embodiment a compression release engine brake is used to load the engine. That increases the turbocharger speed, thereby increasing the pressure and flow of air to the inlet manifold of the engine. Surplus boost air may then be withdrawn from the manifold.