Abstract: An engine having improved volumetric efficiency may include a cylinder, an intake valve, a piston, an exhaust valve and a crankshaft. The cylinder may include a cylinder bore. The intake valve may be configured to introduce a fuel and an air into the cylinder bore. The piston may be slidably arranged in the cylinder bore. The piston may be configured to convert an explosive power of an exhaust gas, which may be generated by combusting the fuel, into a linear driving force. The exhaust valve may be configured to exhaust the exhaust gas from the cylinder bore. The crankshaft may be connected with the piston to convert the linear driving force into a rotary driving force. The intake valve and the exhaust valve may be simultaneously opened within a rotation angle of about 3° to about 12° of the crankshaft.

Abstract: An engine having improved volumetric efficiency may include a cylinder, an intake valve, a piston, an exhaust valve and a crankshaft. The cylinder may include a cylinder bore. The intake valve may be configured to introduce a fuel and an air into the cylinder bore. The piston may be slidably arranged in the cylinder bore. The piston may be configured to convert an explosive power of an exhaust gas, which may be generated by combusting the fuel, into a linear driving force. The exhaust valve may be configured to exhaust the exhaust gas from the cylinder bore. The crankshaft may be connected with the piston to convert the linear driving force into a rotary driving force. The intake valve and the exhaust valve may be simultaneously opened within a rotation angle of about 3° to about 12° of the crankshaft.