Abstract: An internal combustion engine includes an engine block, a piston, and a cylinder head. The engine block includes a cylinder block having a cylinder bore, a crankcase defining a crankcase chamber with a crankshaft positioned within the crankcase chamber, and a cylinder sleeve fabricated from a self-lubricating plastic material. The cylinder head is coupled to the cylinder block to form a combustion chamber. The piston includes a piston top adjacent the combustion chamber, a piston body including a wrist pin hole configured to receive a wrist pin, a first piston ring positioned on the piston body, and a non-metallic gasket positioned on the piston body closer to the combustion chamber than the first piston ring and structured to prevent combustion gases from escaping the combustion chamber. The crankcase chamber is oilless.

Abstract: An internal combustion engine includes an engine block, a piston, a cylinder head, and a valve train. The engine block includes a cylinder block including a cylinder bore and a crankcase defining a crankcase chamber with a crankshaft positioned within the crankcase chamber. The piston is coupled to the crankshaft and configured to reciprocate within the cylinder bore. The cylinder head is coupled to the cylinder block. The valve train includes a camshaft, a first and second pushrod, a first and second rocker arm, an exhaust valve housed, and an intake valve. The first rocker arm, the second rocker arm, the exhaust valve, and the intake valve each include at least a layer of a low friction material. The first and second pushrod each pass through a pushrod seal to prevent fluid from reaching the rocker chamber to fluidly isolate the rocker chamber from the crankcase chamber.

Abstract: An internal combustion engine includes an engine block, a piston, a cylinder head, and a valve train. The engine block includes a cylinder block including a cylinder bore and a crankcase defining a crankcase chamber with a crankshaft positioned within the crankcase chamber. The piston is coupled to the crankshaft and configured to reciprocate within the cylinder bore. The cylinder head is coupled to the cylinder block. The valve train includes a camshaft, a first and second pushrod, a first and second rocker arm, an exhaust valve housed, and an intake valve. The first rocker arm, the second rocker arm, the exhaust valve, and the intake valve each include at least a layer of a low friction material. The first and second pushrod each pass through a pushrod seal to prevent fluid from reaching the rocker chamber to fluidly isolate the rocker chamber from the crankcase chamber.