Following Alfa Romeo is Nissan and Honda. In 1987 and 1989, the two Japanese companies developed their own dual overhead camshaft systems, also known as the NVCS and VTEC systems. In 1992, BMW also developed its own Vanos system, first used on the intake camshaft, and later in 1998, launched their dual Vanos system. Porsche's approach is to apply a chain between the two camshafts to adjust the valve timing.
Note: VVT solenoid factory, oil control valve manufacturer, cam phaser supplier, cam phaser factory.