Abstract: A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

Abstract: A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

Abstract: A dual pipe exhaust manifold includes an inner pipe, an outer pipe and a plurality of spacers. The inner pipe includes a plurality of branch pipes and a plurality of collector pipes. The collector pipes are slidably connected to each other. One end of each of the branch pipe is fixed to a flange section configured and arranged to be attached to a cylinder head of an engine, and the other end of each of the branch pipe is slidably connected to a corresponding one of the collector pipes so that each of the collector pipes is connected to a plural number of the branch pipes. The outer pipe covers a circumference of the inner pipe. The spacers are disposed between the outer pipe and the inner pipe to form a gap therebetween.

Abstract: An exhaust manifold has a structure such that an end portion of a collecting section where pipes connected to respective cylinders of an engine are collected is connected to an exhaust pipe via a joint tube member. The joint tube member is constituted by an upper joint portion and a lower joint portion, and cut-out grooves are formed on both joining portions of the upper joint portion or the lower joint portion. With the cut-out grooves, a partition plate is engaged to be positioned, and in this state, the partition plate is fixed to the upper joint portion or the lower joint portion.

Abstract: An exhaust manifold has a structure such that an end portion of a collecting section where pipes connected to respective cylinders of an engine are collected is connected to an exhaust pipe via a joint tube member. The joint tube member is constituted by an upper joint portion and a lower joint portion, and cut-out grooves are formed on both joining portions of the upper joint portion or the lower joint portion. With the cut-out grooves, a partition plate is engaged to be positioned, and in this state, the partition plate is fixed to the upper joint portion or the lower joint portion.

Abstract: An exhaust-gas recombustion system for recombusting exhaust gases coming out of exhaust ports of an internal combustion engine equipped with a catalytic converter, comprises a plurality of branch pipes of an exhaust manifold connected to the exhaust ports, a plurality of secondary air injection tubes each connected to either one of the branch pipes for recombusting the exhaust gases coming out of the exhaust ports by secondary air injection. An air-injection nozzle of the secondary air injection tube is directed towards the exhaust port communicating with the connected branch pipe along the axial line of the exhaust port. Additionally, the air-injection nozzle is arranged close to a curved wall of the connected branch pipe to effectively sweep away resultant exhaust gases left in the exhaust port and consequently to assure a rapid activation of the catalytic converter during a cold start of the engine.