A multi-cylinder engine includes an engine body having first and second cylinder groups, first and second exhaust passage groups each having a plurality of independent exhaust passage parts and a collective exhaust passage part, and an exhaust gas recirculation (EGR) passage. In a plan view in cylinder axis directions, the passage groups are disposed adjacent to each other, and, in the first exhaust passage group, a first independent exhaust part of the plurality of independent exhaust passage parts is connected to the EGR passage and a second independent exhaust passage part is connected to the collective exhaust passage part so as to be directed to a connection of the first independent exhaust passage part to the collective exhaust passage part, and in the second exhaust passage group, an opening of the collective exhaust passage part is offset toward the first exhaust passage group in a lineup direction.

A multi-cylinder engine includes an engine body having first and second cylinder groups, first and second exhaust passage groups each having a plurality of independent exhaust passage parts and a collective exhaust passage part, and an exhaust gas recirculation (EGR) passage. In a plan view in cylinder axis directions, the passage groups are disposed adjacent to each other, and, in the first exhaust passage group, a first independent exhaust part of the plurality of independent exhaust passage parts is connected to the EGR passage and a second independent exhaust passage part is connected to the collective exhaust passage part so as to be directed to a connection of the first independent exhaust passage part to the collective exhaust passage part, and in the second exhaust passage group, an opening of the collective exhaust passage part is offset toward the first exhaust passage group in a lineup direction.

Methods and systems are provided for a cam drive system of an engine. In one example, a front end of an engine includes an idler gear assembly including an idler gear and idler pulley, the idler gear in meshing engagement with a first end of a crankshaft and the idler pulley coupled to and sharing a rotational axis with the idler gear. The front end of the engine may further include first and second camshaft pulleys positioned vertically above the idler gear assembly and a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley.

The present invention relates to an exhaust gas heat exchanger capable of controlling the cooling performance. The exhaust gas heat exchanger includes: a cooler through which cooling water flows and in which a plurality of gas tubes is provided to allow exhaust gas to flow; an intake and exhaust block including an intake part, a supply line, a discharge line, a bypass line, and a first flap; a U-turn block including an inflow part, a re-cooling line, a release line, and a second flap; and an air duct.

A thermoelectric generator for a vehicle utilizing heat of exhaust gas discharged from an engine of the vehicle includes a heat exchange unit, through which a coolant circulates, a thermoelectric generation unit for converting thermal energy of exhaust gas into electrical energy, a first flow passage for guiding the exhaust gas to pass through the heat exchange unit, a second flow passage for guiding the exhaust gas to pass through the thermoelectric generation unit, a third flow passage for guiding the exhaust gas to bypass the heat exchange unit and the thermoelectric generation unit without passing therethrough, a first valve for opening or closing the first flow passage, a second valve for selectively opening or closing the second flow passage and the third flow passage, and a driving unit for operating the first valve and the second valve by a single power source.

A fuel passage leads a fuel from a pressure-accumulation vessel to a nozzle hole of a fuel injection valve. A fuel pressure sensor detects a fuel pressure in a fuel passage. An estimation device is applicable to a combustion system, which includes these components, and includes a mixing acquisition unit and an injection amount estimation unit. The mixing acquisition unit acquires the mixing ratio of various components contained in the fuel used for combustion in the internal combustion engine. The injection amount estimation unit estimates an injection amount of the fuel from the nozzle hole according to a change mode of the fuel pressure, which is detected with the fuel pressure sensor and associated with injection of the fuel from a nozzle hole, and the mixing ratio acquired with the mixing acquisition unit.

A fuel passage leads a fuel from a pressure-accumulation vessel to a nozzle hole of a fuel injection valve. A fuel pressure sensor detects a fuel pressure in a fuel passage. An estimation device is applicable to a combustion system, which includes these components, and includes a mixing acquisition unit and an injection amount estimation unit. The mixing acquisition unit acquires the mixing ratio of various components contained in the fuel used for combustion in the internal combustion engine. The injection amount estimation unit estimates an injection amount of the fuel from the nozzle hole according to a change mode of the fuel pressure, which is detected with the fuel pressure sensor and associated with injection of the fuel from a nozzle hole, and the mixing ratio acquired with the mixing acquisition unit.

An engine 1 includes an exhaust manifold, an intake manifold, and an EGR device configured to supply EGR gas from the exhaust manifold to the intake manifold. An upper end of the EGR cooler extended downward is attached to a downwardly extending attachment part provided to the exhaust manifold.

Methods and systems are provided for a cooling arrangement of an engine. In one example, a method comprises flowing coolant from a high temperature coolant circuit or a low temperature coolant circuit to a fresh air heat exchanger in response to a condensate likelihood.

Methods and systems are provided for a cooling arrangement of an engine. In one example, a method comprises flowing coolant from a high temperature coolant circuit or a low temperature coolant circuit to a fresh air heat exchanger in response to a condensate likelihood.