A synchronized, dual crankshaft engine (10) uses a phase-shifting device (42) to alter the angular position of one crankshaft (12) relative to the other crankshaft (14) for dynamically varying the engine's developed compression ratio. Each crankshaft (12, 14) drives a respective connecting rod (16, 18) which, in turn, reciprocates a piston (24, 26) in a cylinder (28, 30). The center lines (C, D) of each cylinder (28, 30) are skewed relative to each other so that the pistons (24, 26) converge toward a common combustion chamber formed under a common cylinder head (34). Movable exhaust valves (36) are located above the piston (24) whose phase shifted orientation is retarded or lagging dead center conditions, whereas movable intake valves (38) are located above the piston (26) that is leading or advanced in its phase displacement relative to dead center conditions.
