Abstract: A preferred embodiment EGR valve permits exhaust gas to be induced into the intake line downstream of the compressor, while minimizing the need to reduce the size of the turbocharger. The preferred embodiment EGR valve exploits variations around the mean pressure in the EGR passage created by the engine cycle by selectively opening when the pressure in the EGR valve exceeds the pressure in the intake line. Thus, exhaust gas is recirculated even when the engine is running near torque peak. The preferred embodiment EGR valve also exploits the higher mean pressure in the exhaust line relative to the intake line at higher engine speeds by remaining open, in order to minimize the energy consumed in opening and closing the EGR valve.

Abstract: A hydraulically actuated dual fuel injector separately injects two fuels into a combustion chamber of an internal combustion engine. In particular, the two fuels may be controlled quantities of a first liquid fuel and a second gaseous fuel that are used to fuel a diesel engine. The injector preferably begins injecting the first fuel sequentially before beginning to inject the second fuel.