An intake swirl gasket is disclosed herein. It is installed between a cylinder head and an intake manifold and comprises plural airflow holes for respectively communicating with plural intake passages of the cylinder head; and plural diversion devices respectively disposed in the plural airflow holes and each having an axis and plural splitter blades extended from the axis for connecting to an inner wall of each of the plural airflow holes, wherein each of the plural splitter blades is shaped as an arc to form a recessed surface towards the intake manifold at one side thereof and a convex surface towards the cylinder head at the other side thereof, and wherein an included angle between each of the plural splitter blades and an end face of the intake swirl gasket oriented towards the cylinder head ranges from 50 to 80 degrees.

A gas-liquid separator includes a cylindrical inlet pipe and a fluid inflow pipe. The inlet pipe includes a fluid inlet which is formed in a fluid entering side and radially opens. An axis line of the inlet pipe horizontally extends. The fluid inflow pipe includes at an end a connection opening connected to the fluid inlet. An axis line of the fluid inflow pipe horizontally extends. The fluid inflow pipe introduces the gas-liquid two-phase fluid through the fluid inlet from a side of the inlet pipe. In a connecting portion, a position of an axis line extending through a center of a connection opening in communication with the fluid inlet is vertically offset with respect to a position of the axis line of the inlet pipe.

An intake swirl gasket is disclosed herein. It is installed between a cylinder head and an intake manifold and comprises plural airflow holes for respectively communicating with plural intake passages of the cylinder head; and plural diversion devices respectively disposed in the plural airflow holes and each having an axis and plural splitter blades extended from the axis for connecting to an inner wall of each of the plural airflow holes, wherein each of the plural splitter blades is shaped as an arc to form a recessed surface towards the intake manifold at one side thereof and a convex surface towards the cylinder head at the other side thereof, and wherein an included angle between each of the plural splitter blades and an end face of the intake swirl gasket oriented towards the cylinder head ranges from 50 to 80 degrees.

A gas-liquid separator includes a cylindrical inlet pipe and a fluid inflow pipe. The inlet pipe includes a fluid inlet which is formed in a fluid entering side and radially opens. An axis line of the inlet pipe horizontally extends. The fluid inflow pipe includes at an end a connection opening connected to the fluid inlet. An axis line of the fluid inflow pipe horizontally extends. The fluid inflow pipe introduces the gas-liquid two-phase fluid through the fluid inlet from a side of the inlet pipe. In a connecting portion, a position of an axis line extending through a center of a connection opening in communication with the fluid inlet is vertically offset with respect to a position of the axis line of the inlet pipe.

An intake manifold 10 includes: a blowby gas introduction port 16g that is configured to introduce blowby gas into a PCV chamber 15; a blowby gas exhaust port 16f that is configured to discharge the blowby gas from the PCV chamber 15 into a surge tank 11; and a drain hole 17c that is configured to discharge water contained in the blowby gas, from the PCV chamber 15 into the surge tank 11. A bottom wall 17d of the surge tank 11 includes protruding parts 17e, 17f that protrude upward, the blowby gas exhaust port 16f is located upstream of the most upstream side protruding part 17e located on the most upstream side, and the drain hole 17c is located downstream of the most upstream side protruding part.

An intake manifold 10 includes: a blowby gas introduction port 16g that is configured to introduce blowby gas into a PCV chamber 15; a blowby gas exhaust port 16f that is configured to discharge the blowby gas from the PCV chamber 15 into a surge tank 11; and a drain hole 17c that is configured to discharge water contained in the blowby gas, from the PCV chamber 15 into the surge tank 11. A bottom wall 17d of the surge tank 11 includes protruding parts 17e, 17f that protrude upward, the blowby gas exhaust port 16f is located upstream of the most upstream side protruding part 17e located on the most upstream side, and the drain hole 17c is located downstream of the most upstream side protruding part.