Abstract: A rotary valve shaft indent system for use in internal combustion engines including an intake manifold, and exhaust manifold, at least one combustion chamber having a piston and an ignition point, a cylinder head, an intake shaft rotatably mounted within the cylinder head and having at least one intake indent disposed thereon, and an exhaust shaft rotatably mounted within the cylinder head and having at least one exhaust indent disposed thereon. Upon rotation of the intake and exhaust shafts, the intake indent allows for intermittent connection of the intake manifold and the combustion chamber, and the exhaust indent allows for intermittent connection of the combustion chamber and the exhaust manifold.