 An evolution of the M113 V8, all M273s have aluminium engine blocks, sequential fuel injection, forged steel connecting rods, a one-piece cast camshaft, and a magnesium intake manifold.The cylinders are lined with silicon/aluminium, and a dual-length Variable Length Intake Manifold is fitted.In addition to this, new features shared with the M272 include DOHC aluminium cylinder heads, 4 valves per cylinder and independent continuously variable valve timing on both the intake and exhaust sides.