Multiple valve engine for watercraft

A watercraft comprising an internal combustion engine and a hull defining a center plane extending generally vertically from bow to stern, the internal combustion engine comprising a cylinder body mounted within the hull, the cylinder body defining at least one cylinder bore, a piston reciprocating within the cylinder bore, a crankshaft, a connecting rod pivotally connecting the crankshaft with the piston, the piston having a pivot axis at which the connecting rod is pivotally coupled with the piston, the pivot axis generally lying within the center plane during at least one point of reciprocal travel of the piston within the cylinder bore, a cylinder head member closing an end of the cylinder bore and defining a combustion chamber with the cylinder bore and the piston, the cylinder head member slanting toward one side of the hull from the center plane, a plurality of air intake paths introducing air to the combustion chamber, and at least one exhaust path receiving exhaust gases from the combustion chamber, the number of air intake paths being greater than the number of the exhaust paths, air intake valves arranged to selectively open and close the air intake paths, at least one exhaust valve arranged to open and close the at least one exhaust path, an intake camshaft arranged to actuate the intake valves, an exhaust camshaft arranged to actuate the exhaust valve, both the intake and exhaust camshafts extending generally in parallel to the center plane, and the intake camshaft lying closer to the center plane than the exhaust camshaft.

A watercraft comprising an internal combustion engine and a hull defining a center plane extending generally vertically from bow to stern, the internal combustion engine comprising a cylinder body defining at least one cylinder bore, a piston reciprocating within the cylinder bore, a connecting rod coupled to the piston, a crankshaft including at least one connecting rod journal having an axis about which the connecting rod moves, a cylinder head member closing an end of the cylinder bore and defining a combustion chamber with the cylinder bore and the piston, a first passage comprising at least two paths communicating with the combustion chamber, a first valve device comprising at least two valves arranged to selectively connect and disconnect the paths of the first passage with the combustion chamber, a second passage comprising at least one path communicating with the combustion chamber, the second passage having a fewer in number of paths than that of the first passage, and a second valve device comprising at least one valve arranged to selectively connect and disconnect the at least one path of the second passage with the combustion chamber, the first valve device being disposed closer to the center plane than the second valve device, the engine being disposed within the hull such that the rotational axis of the crankshaft lies to one side of the center plane and both the first and second valve devices are disposed on the other side of the center plane, the rotational axis of the crankshaft being substantially offset from the center plane to at least partially counterbalance the weight of the first and second valve devices.

A watercraft comprising an internal combustion engine and a hull defining a center plane extending generally vertically from bow to stern, the internal combustion engine comprising a cylinder body mounted within the hull, the cylinder body defining at least one cylinder bore, a piston reciprocating within the cylinder bore, a connecting rod coupled to the piston, a crankshaft including at least one connecting rod journal having an axis about which the connecting rod moves, a cylinder head member closing an end of the cylinder bore and defining a combustion chamber with the cylinder bore and the piston, a plurality of air intake passages introducing air to the combustion chamber, and at least one exhaust passage receiving exhaust gases from the combustion chamber, the number of air intake passages being greater than the number of exhaust passages, air intake valves arranged to selectively open and close the air intake passages, at least one exhaust valve arranged to open and close the at least one exhaust passage, an intake camshaft arranged to actuate the intake valves, an exhaust camshaft arranged to actuate the exhaust valve, the intake camshaft lying closer to the center plane than the exhaust camshaft, the engine being disposed within the hull such that the rotational axis of the crankshaft lies to one side of the center plane and both the intake and exhaust camshafts rotate about axes that lie on the other side of the center plane, the rotational axis of the crankshaft being substantially offset from the center plane to at least partially counterbalance the weight of the first and second valve devices.