Patent ID: 10054061

Abstract:
An engine includes a cylinder body, a cylinder head, and an ignition device including spark plugs. The engine also includes an intake device connected to intake ports, an exhaust device connected to exhaust ports, pistons, and a crankshaft connected to the pistons by connecting rods. Explosion intervals of the cylinders are 270°, 180°, 90°, and 180° as crank angles. The engine further includes a discomfort eliminator which, when the engine speed is lower than a predetermined value, makes the indicated mean effective pressure of at least one of two cylinders having an explosion interval of 90° lower than the indicated mean effective pressures of the other cylinders having an explosion interval of not 90°. The engine causes unequal-interval explosions but produces little change in the driving energy per unit time during an operating state in which an occupant is liable to feel torque fluctuations.