Patent ID: 7584724

Claim:
In a dual crankshaft engine, wherein said crankshafts are supported for rotation about respective parallel axes, said engine comprising: a pair of crankshafts supported for independent rotation about respective axes oriented parallel to each other; first and second cylinders, each said cylinder associated with a different one of said crankshafts; a piston disposed for reciprocating movement in each of said first and second cylinders; a connecting rod pivotally connected at an upper end thereof to each said piston and at an opposite, lower end thereof to a respective one of said crankshafts; a common cylinder head communicating simultaneously with said first and second cylinders, said cylinder head including at least one moveable intake valve and one moveable exhaust valve and a spark plug; a phasing device interconnecting said crankshafts; said phasing device synchronizing rotation of said crankshafts and selectively operable to temporarily interrupt synchronized rotation so as to change the angular position of one said crankshaft relative to the other said crankshaft and then resume synchronized rotation with said crankshafts in a new, phase-shifted condition relative to each other, whereby said phasing device can dynamically vary the compression ratio developed by said engine by altering the phase shift between said synchronized crank shafts; said first and second cylinders defining respective longitudinal centerlines, wherein each said centerline perpendicularly intersects the rotational axis of the respective one of said crankshafts, and wherein the spacing between said centerlines varies as a function of distance from said crankshaft axes; and wherein the spacing between said longitudinal centerlines is greater adjacent said crankshaft axes and lesser adjacent said cylinder head; and wherein each of said first and second cylinders define a circular cross-section centered along said respective longitudinal axis, and wherein at least one of said intake and exhaust valves is disposed partially outside of an imaginary extension of said circular cross-section projected onto said cylinder head.