Crossover valve in double piston cycle engine

An internal combustion engine, comprising:

• a combustion chamber with a first aperture;
• a compression chamber with a second aperture;
• and
• a crossover valve comprising an internal chamber, first and second valve seats, a valve head, and first and second valve faces on the valve head, wherein
• the first aperture allows fluid communication between the combustion chamber and the internal chamber,
• the second aperture allows fluid communication between the compression chamber and the internal chamber,
• the first valve face couples to the first valve seat to occlude the first aperture,
• the second valve face couples to the second valve seat to occlude the second aperture;
• and
• the valve head moves within the internal chamber so that the crossover valve alternatively occludes the first aperture and the second aperture;
• and
• a bias that provides a force to assist the valve head move within the internal chamber in the direction of both the first and the second apertures, wherein the bias further comprises a camshaft, a camshaft follower, a rocker, a return spring, and a push rod.