Abstract:
An assembly includes a cylinder head with an integrated exhaust manifold that has four exhaust flow passages directing cylinder exhaust from inlets arranged to correspond with exhaust from the four cylinders, respectively, and has only three outlets. The assembly includes a twin scroll turbocharger having a housing with a first scroll passage, a second scroll passage, and only three inlets. Two of the exhaust flow passages join in the cylinder head to direct exhaust flow into only one of the inlets of the housing and through the first scroll passage. Exhaust flow through the other two of the exhaust flow passages flows separately into the other two inlets in the housing and joins in the housing to flow through the second scroll passage.
Abstract:
A method includes: generating an indicator of present operating conditions of an engine; determining a first amount of noise based on vibration measured during a first plurality of combustion events of a cylinder; storing the first amount of noise and a first value of the indicator in a mapping based on a first engine speed and a first engine load; determining the first value of the indicator from the mapping based on a second engine speed and a second engine load; generating a trigger signal when the first value is different than a second value of the indicator; and, when the trigger signal is generated: determining a second amount of noise based on vibration measured during a second plurality of combustion events of the cylinder; and replacing the first amount of noise and the first value in the mapping with the second amount of noise and the second value.
Abstract:
A system according to the principles of the present disclosure includes a stochastic pre-ignition module and a fuel control module. The stochastic pre-ignition module determines whether operating conditions of an engine satisfy predetermined criteria associated with stochastic pre-ignition. The fuel control module enriches an air/fuel ratio of the engine when the engine operating conditions satisfy the predetermined criteria.
Abstract:
A camshaft assembly includes a base shaft extending along a longitudinal axis. The base shaft is configured to rotate about the longitudinal axis. The camshaft assembly further includes a series of lobe packs mounted on the base shaft. The lobe pack includes a first cam lobe, a second cam, and a third cam lobe. The lobe pack further includes a barrel cam defining a control groove. The camshaft assembly further includes an actuator including an actuator body and at least one pin movably coupled to the actuator body. The lobe pack is configured to move axially relative to the base shaft between a first position, a second position, and a third position. These three lobe pack positions are used to define three discrete valve lift profiles for the intake or exhaust valves in the cylinder. The lift profiles can be different for each engine valve.
Abstract:
A system according to the principles of the present disclosure includes a stochastic pre-ignition module and a fuel control module. The stochastic pre-ignition module determines whether operating conditions of an engine satisfy predetermined criteria associated with stochastic pre-ignition. The fuel control module enriches an air/fuel ratio of the engine when the engine operating conditions satisfy the predetermined criteria.