Engine intake system and control method thereof

A method of controlling an engine intake system including:

• a port partition disposed to divide an intake port of a cylinder head into an upper portion and a lower portion;
• a first intake manifold configured to supply air, which flows from an air cleaner through a charger and an intercooler, to the lower portion of the port partition;
• a second intake manifold configured to supply the air, which flows from the air cleaner while bypassing the charger and the intercooler, to the upper portion of the port partition;
• and a bypass valve disposed at an inlet of a bypass duct and configured to pass and block the air flowing into the second intake manifold from the air cleaner, the method comprising:
• determining whether a cooling water temperature of an engine, an engine Revolutions Per Minute (RPM), and an engine torque satisfy predetermined reference conditions, respectively;
• closing the bypass valve upon determining that the cooling water temperature, the engine RPM, and the engine torque satisfy all the reference conditions;
• and
• opening the bypass valve when at least one of the cooling water temperature, the engine RPM, or the engine torque does not satisfy the reference condition thereof.