An engine assembly may include an engine having a plurality of combustion cylinders, and an exhaust manifold configured to receive exhaust from the plurality of combustion cylinders. The exhaust manifold may be divided into first and second sections. The first section may be fluidly coupled to a first group of combustion cylinders, and the second section may be fluidly coupled to a second group of combustion cylinders. The engine assembly may also include a turbocharger having an exhaust turbine configured to receive exhaust from the first section. The engine assembly may further include a proportional valve assembly configured to selectively fluidly couple the second section to at least one of the turbocharger and an exhaust recirculation loop.
U.S. GOVERNMENT RIGHTS
 This invention was made with government support under the terms of DE-FC05-00OR22806 awarded by the Department of Energy. The government may have certain rights in this invention.