Abstract: An engine lubrication system for a multi-cylinder engine, comprising: plurality of crank chambers that are partitioned by crankshaft bearing portions of the engine; pumps that take out oil from a lower portion of the engine; oil collection passages that are respectively provided for the crank chambers, a designated number of the oil collection passages being merged and connected to at least one of suction ports of the pumps; an oil storage section that temporarily stores the oil taken out from the lower portion of the engine; a lubrication part that supplies the oil in the oil storage section to a portion to be lubricated of the engine; and a pressure variation suppression section that is provided between the suction ports of the pumps and the designated number of the crank chambers to be merged, the pressure variation suppression section suppressing pressure variations in the crank chambers.

Abstract: An engine can include a first catalyst disposed in a first exhaust passage, a second catalyst disposed in a second exhaust passage to be located upstream of the first catalyst, a variable valve operating mechanism configured to make lifting amounts of a first and second exhaust valves variable between approximate zero and maximum, and a lifting amount control unit for controlling the lifting amounts of the first and second exhaust valves with the variable valve operating mechanism such that an exhaust gas amount passing through the second exhaust passage is larger than that passing through the first exhaust passage.

Abstract: An engine lubrication system for a multi-cylinder engine, comprising: plurality of crank chambers that are partitioned by crankshaft bearing portions of the engine; pumps that take out oil from a lower portion of the engine; oil collection passages that are respectively provided for the crank chambers, a designated number of the oil collection passages being merged and connected to at least one of suction ports of the pumps; an oil storage section that temporarily stores the oil taken out from the lower portion of the engine; a lubrication part that supplies the oil in the oil storage section to a portion to be lubricated of the engine; and a pressure variation suppression section that is provided between the suction ports of the pumps and the designated number of the crank chambers to be merged, the pressure variation suppression section suppressing pressure variations in the crank chambers.

Abstract: An engine can include a first catalyst disposed in a first exhaust passage, a second catalyst disposed in a second exhaust passage to be located upstream of the first catalyst, a variable valve operating mechanism configured to make lifting amounts of a first and second exhaust valves variable between approximate zero and maximum, and a lifting amount control unit for controlling the lifting amounts of the first and second exhaust valves with the variable valve operating mechanism such that an exhaust gas amount passing through the second exhaust passage is larger than that passing through the first exhaust passage.