Engine intake system

An intake system of an engine, comprising:

• an intake manifold, attached to a cylinder head of the engine and formed by joining a plurality of members, the intake manifold including:
• an intake air introducing pipe having a tubular passage and configured to introduce fresh air;
• and
• a plurality of independent intake pipes, each having a tubular passage, attached to the cylinder head of the engine and configured to guide the fresh air to respective intake ports formed in the cylinder head,
• wherein the intake air introducing pipe is formed so as to extend in a cylinder lined-up direction of the engine,
• wherein each of the plurality of independent intake pipes is formed in an arc shape so as to surround the intake air introducing pipe from outside, with a space from a peripheral surface of the intake air introducing pipe opposite from the engine,
• wherein, when the intake manifold is seen from the front in an intake-and-exhaust direction of the engine, among the plurality of independent intake pipes, a first independent intake pipe located at one end in the cylinder lined-up direction is curved more in the cylinder lined-up direction than a second independent intake pipe different from the first independent intake pipe,
• wherein, when the intake manifold is seen from the side in the cylinder lined-up direction, the arc shape of the second independent intake pipe is more distant from the intake air introducing pipe than the first independent intake pipe is, and
• wherein the plurality of members constituting the intake manifold includes:
• a first member constituting a part of a peripheral wall of the intake air introducing pipe;
• a second member joined to the first member radially outward of the intake air introducing pipe, wherein joining of the first and second members forms the arc shape of the first independent intake pipe;
• and
• a third member disposed radially outward, with reference to the intake air introducing pipe, of the first member with a gap therebetween, wherein joining of the second and third members forms the arc shape of the second independent intake pipe.