Variable valvetrain turbocharged engine

摘要

Embodiments for routing exhaust in an engine are provided. In one example, an engine method comprises, during a first condition, firing a subset of cylinders and routing all exhaust from the subset of cylinders through a first exhaust manifold coupled directly to a catalyst and not a turbocharger, and during a second condition, firing all cylinders, routing a first portion of exhaust through a second exhaust manifold coupled to the turbocharger, and routing a second portion of exhaust through the first exhaust manifold. In this way, exhaust can be directly routed to a catalyst under some conditions.

主权项

1. An engine system comprising:
a first cylinder including two exhaust ports coupled to a turbocharger via an integrated exhaust manifold; a second cylinder including a first exhaust port coupled to the turbocharger via the integrated exhaust manifold and a second exhaust port coupled to a catalyst and not the turbocharger; and a system including a camshaft with profiles and configured to:
only allow the second exhaust port to open during a first condition, andallow each exhaust port to open during a second condition.