A spark-ignited gas engine system comprises a combustion chamber defined by a piston, a head with a spark plug mechanism, and a cylinder having an associated intake valve and an associated exhaust valve, into which a mixture of combustible gas and air is entered via an intake manifold of the engine to drive a crankshaft. The system further comprises at least one turbocharger to compress the mixture. The system further comprises at least one camshaft, driven by the crankshaft via a gear assembly connected to the crankshaft, that comprises at least one cam that actuates the intake valve and the exhaust valve, at least one camphaser, coupled to the crankshaft via the gear assembly, and a controller to adjust a cam angle operation of the intake valve and the exhaust valve by adjusting the camphaser to a desired phase position to meet a target rotational phase of the camshaft.