Four-cycle internal combustion engine and associated methods of fuel combustion

Claim 1

A four-cycle internal combustion engine comprising a cylinder block having a cylinder bore therein, a piston slidably fitted in said bore, a cylinder head on said block, said cylinder head being provided with a combustion chamber merging with said cylinder bore, said piston, cylinder bore and combustion chamber having a transverse cross-section of non-circular shape with a major longitudinal axis and a minor transverse axis, vertical planes passing through said longitudinal and transverse axes intersecting along a central axis passing through the center of the cylinder bore and combustion chamber, said combustion chamber having a central region and an outer region, inlet means including inlet valves for introducing fuel mixture into said combustion chamber only in said central region of the combustion chamber and discharge means including discharge valves for discharging exhaust gases from said combustion chamber only at said outer region of said combustion chamber, said inlet valves all being arranged around said central axis at substantially equal distances therefrom, said discharge valves all being arranged around said central axis at substantially equal distances therefrom, the distance of said inlet valves from said central axis being less than the distance of said discharge valves from said central axis, said inlet valves of said inlet means comprising a pair of inlet valves on opposite sides of said vertical plane passing through said transverse axis, said discharge valves of said discharge means comprising a pair of exhaust valves on opposite sides of said vertical plane passing through said transverse axis in said outer region outside said inlet valves, wherein said pairs of inlet valves and exhaust valves are arranged along a common line in a row substantially parallel to the major longitudinal axis and wherein the exhaust valves are outside the inlet valves.