Internal combustion engine piston type.

Internal combustion engine (10) of the piston type having an inlet duct (20) for supplying air to combustion chambers of the engine and an exhaust system (15, 22) for extracting exhaust gases from said combustion chambers, the exhaust system comprising equipment (29, 30) to reduce emissions of harmful exhaust to the environment of the engine, which is intended to operate with variable in order to propel a vehicle load, the exhaust system (15, 22) comprises a branch pipe (26) controlled by a valve (24) and deriving at least a portion of said equipment (29, 30) to reduce emissions of harmful exhaust to the environment, the valve (24) is controlled shape conducting the flow of exhaust gas through the branch pipe (26) in a part of the total range of engine load and the engine is optimized to provide emission acceptable escape in that part of the total range AC RGA engine characterized in that the branch pipe (26) is coupled in parallel with an aftertreatment system exhaust comprising an SCR catalytic converter (30) and a filter regeneratable particle (30) course is set up valve (24), while the regeneration gas flow being possible exhaust is conducted through the branch pipe (26).