Internal combustion engine with rotary valve

An axial flow rotary valve internal combustion engine comprising:

• at least one rotary valve rotatable about an axis within a bore of a cylinder head, said valve communicating with a respective cylinder in which a piston reciprocates, and
• an ignition means associated with said cylinder, said rotary valve having an outside diameter less than 0.85 times a diameter of said cylinder,
• an inlet port extending from an inlet axial opening at one end of said valve and terminating as an inlet peripheral opening in a periphery of said valve,
• an exhaust port extending from an exhaust axial opening at the opposite end of said valve and terminating as an exhaust peripheral opening in the periphery of said valve, said peripheral openings periodically communicating with said cylinder through a window in said bore as said valve rotates, said window having a first window end proximate to said inlet axial opening and a second window end remote from said inlet axial opening,
• a combustion chamber formed in a space between a crown of said piston at top dead center and said cylinder head and said valve, said head having a combustion surface surrounding said window and extending to a wall of said cylinder,
• wherein said window and said valve are substantially centrally disposed about a first plane within which the axis of said cylinder lies, said ignition means comprising first and second spark plugs, each of said spark plugs having a nose located at one end thereof exposed to said combustion chamber through said combustion surface,
• said noses being disposed on opposite sides of said window within axial extremities of said window, and an intersection point of an axis of each of said spark plugs with said combustion surface is radially inside said wall of said cylinder by a distance of at least 0.1 times the diameter of said cylinder, and
• said combustion chamber has first and second squish zones, at least a portion of each of said first and second squish zones being between the wall of said cylinder and the nose of each of said first and second spark plugs respectively.