Profile: Mechadyne International Ltd. specializes in offering valve actuation services. Our concentric camshafts enable dual-independent variable valve timing or VVT on a single camshaft. Both the intake and exhaust centerline timings can be controlled to provide optimum engine performance over the complete operating range. These cam assemblies form a key part of many of our VVA systems, but they are ideal for cam in block pushrod engines. Our concentric camshafts are used in our variable lift and duration system.