There is provided a V-type engine, in which deck cylinder parts of a cylinder block are offset in the same direction as a rotational direction of a crankshaft, and oil separation chambers are provided at an upper portion of the cylinder head displaced to a lower side by the offset. Therefore, an allowance in the axial direction of cylinders may be provided above a cylinder head of the deck cylinder parts on the lower side, and the capacity of the oil separation chambers is increased by the allowance so that the oil separation performance may be improved, while an increase in the total width and total height of an engine block is suppressed.
1. A V-type engine, comprising:
a cylinder block formed with deck cylinder parts protruded in V-shape; and
cylinder heads provided at respective heads of said deck cylinder parts, said cylinder block being constructed such that the deck cylinder parts are offset in a direction identical with a rotational direction of a crankshaft; and
oil separation chambers, that separate oil from blow-by gas, provided at upper portion of said cylinder head displaced to a lower side by the offset.
2. A V-type engine according to claim 1 , wherein
the oil separation chambers are also provided at upper portion of said cylinder head displaced to a higher side by the offset, and
the oil separation chambers on the lower side are longer in an axial direction than the oil separation chambers on the higher side.
3. A V-type engine according to claim 2 , wherein among intake passages that lead intake air to the deck cylinder parts, a first air vent passage extended to an intake area located downstream across a throttle valve is connected to the oil separation chambers on the lower side.
4. A V-type engine according to claim 3 , wherein among the intake passages that lead intake air to the deck cylinder parts, a second air vent passage extended to an intake area located upstream across the throttle valve is connected to the oil separation chambers on the higher side.
5. A V-type engine according to claim 2 , wherein the oil separation chambers on the lower side are configured to cause blow-by gas generated inside the V-type engine in an overall operation range of the V-type engine to flow back toward intake ports, and the oil separation chambers on the higher side are configured to cause blow-by gas generated inside the V-type engine only during a high-load operation of the V-type engine to flow back toward the intake ports.