Abstract: An engine system may include: an engine including a plurality of combustion chambers generating driving torque by burning fuel; an intake line through which fresh air flows into the combustion chambers; an intake manifold for distributing fresh air supplied by the intake line to the combustion chambers; an exhaust line in which exhaust gas exhausted from the combustion chambers flows; a recirculation line branched from the exhaust line and joined to the intake line; a connection pipe disposed at a portion where the recirculation line and the intake line are joined; and a water line connecting the connection pipe and the intake manifold. Condensate water generated at the connection pipe flows in the water line.

Abstract: The present disclosure provides a method and system, for controlling a coolant circulating in an engine, including: selecting a reference inlet temperature for a coolant flowing through a coolant inlet of an engine; controlling an open rate of the coolant control valve unit based on the reference inlet temperature; sensing an actual inlet temperature of the coolant flowing through the coolant inlet of the engine; sensing an actual outlet temperature of a coolant flowing through a coolant outlet of the engine; calculating a difference value between the actual inlet temperature and the actual outlet temperature; and varying the reference inlet temperature according to the difference value.

Abstract: A valve timing control apparatus of an internal combustion engine may include a driving rotational body to which torque is transmitted from a crankshaft, a driven rotational body fixed to a camshaft to which torque is transmitted from the driving rotational body, an electric motor disposed between the driving rotational body and the driven rotational body and relatively rotating the driving rotational body and the driven rotational body when electric power is applied thereto, and a deceleration mechanism that decelerates a rotational speed of the electric motor and transmits the decelerated rotational speed to the driven rotational body.

Abstract: A water jacket for a cylinder block may include a first main body formed inside the cylinder block at a first side thereof, and a second main body formed at a second side thereof, and in which coolant flows, a first sub-body formed at an upper portion of the first main body, and a second sub-body formed at an upper portion of the second main body, each of the first and second sub-bodies being connected to an inside of a cylinder head to flow a coolant into an upper portion of the cylinder block and the cylinder head, a first insert member disposed between the first main body and the first sub-body to partition the first main body and the first sub-body, and a second insert member disposed between the second main body and the second sub-body to partition the second main body and the second sub-body.

Abstract: An engine system may include: an engine including a plurality of combustion chambers generating driving torque by burning fuel; an intake line through which fresh air flows into the combustion chambers; an intake manifold for distributing fresh air supplied by the intake line to the combustion chambers; an exhaust line in which exhaust gas exhausted from the combustion chambers flows; a recirculation line branched from the exhaust line and joined to the intake line; a connection pipe disposed at a portion where the recirculation line and the intake line are joined; and a water line connecting the connection pipe and the intake manifold. Condensate water generated at the connection pipe flows in the water line.

Abstract: The present disclosure provides a method and system, for controlling a coolant circulating in an engine, including: selecting a reference inlet temperature for a coolant flowing through a coolant inlet of an engine; controlling an open rate of the coolant control valve unit based on the reference inlet temperature; sensing an actual inlet temperature of the coolant flowing through the coolant inlet of the engine; sensing an actual outlet temperature of a coolant flowing through a coolant outlet of the engine; calculating a difference value between the actual inlet temperature and the actual outlet temperature; and varying the reference inlet temperature according to the difference value.

Abstract: A water jacket for a cylinder block may include a first main body formed inside the cylinder block at a first side thereof, and a second main body formed at a second side thereof, and in which coolant flows, a first sub-body formed at an upper portion of the first main body, and a second sub-body formed at an upper portion of the second main body, each of the first and second sub-bodies being connected to an inside of a cylinder head to flow a coolant into an upper portion of the cylinder block and the cylinder head, a first insert member disposed between the first main body and the first sub-body to partition the first main body and the first sub-body, and a second insert member disposed between the second main body and the second sub-body to partition the second main body and the second sub-body.

Abstract: A valve timing control apparatus of an internal combustion engine may include a driving rotational body to which torque is transmitted from a crankshaft, a driven rotational body fixed to a camshaft to which torque is transmitted from the driving rotational body, an electric motor disposed between the driving rotational body and the driven rotational body and relatively rotating the driving rotational body and the driven rotational body when electric power is applied thereto, and a deceleration mechanism that decelerates a rotational speed of the electrical motor and transmit the decelerated rotational speed to the driven rotational body.

Abstract: Disclosed is a variable compression ratio device which changes a top dead center of a piston provided in an engine depending on a driving state of the engine. The variable compression ratio device may include: a lower piston reciprocally movable in a cylinder of the engine and connected with a connecting rod to rotate a crankshaft, an operation chamber, an upper piston disposed above the lower piston and partially inserted into the operation chamber, a push plate dividing the operation chamber into upper and lower spaces, a hydraulic pressure chamber which is the lower space, an elastic member provided in the upper space to push the push plate downward, a hydraulic pressure supply unit selectively supplying hydraulic pressure to the hydraulic pressure chamber, and a hydraulic pressure supply pathway connecting the hydraulic pressure supply unit and the hydraulic pressure chamber for supplying the hydraulic pressure.

Abstract: Disclosed is a variable compression ratio device which changes a top dead center of a piston provided in an engine depending on a driving state of the engine. The variable compression ratio device may include: a lower piston reciprocally movable in a cylinder of the engine and connected with a connecting rod to rotate a crankshaft, an operation chamber, an upper piston disposed above the lower piston and partially inserted into the operation chamber, a push plate dividing the operation chamber into upper and lower spaces, a hydraulic pressure chamber which is the lower space, an elastic member provided in the upper space to push the push plate downward, a hydraulic pressure supply unit selectively supplying hydraulic pressure to the hydraulic pressure chamber, and a hydraulic pressure supply pathway connecting the hydraulic pressure supply unit and the hydraulic pressure chamber for supplying the hydraulic pressure.