Abstract: A noise insulation structure of a synthetic resin made conduit includes a synthetic resin made chamber and a rubber made noise insulation member. Since the chamber is closely covered around with the noise insulation member through projections and grooves formed on the contact surface of the chamber with the noise insulation member. Further, cylindrical blind-end bores are provided on the inner surface of the noise insulation member so as to form air columns when the noise insulation member is installed on the chamber. The air columns serve as resonators to muffle noise.

Abstract: A noise insulation structure of a synthetic resin made conduit includes a synthetic resin made chamber and a rubber made noise insulation member. Since the chamber is closely covered around with the noise insulation member through projections and grooves formed on the contact surface of the chamber with the noise insulation member. Further, cylindrical blind-end bores are provided on the inner surface of the noise insulation member so as to form air columns when the noise insulation member is installed on the chamber. The air columns serve as resonators to muffle noise.

Abstract: Commonly, an engine control unit is mounted in an appropriate place of the passenger compartment. According to the present invention, an engine control unit mounting apparatus for accommodating the engine control unit is directly mounted on the engine utilizing a space of the bank offset on either side of the left or right bank. The engine control unit mounting apparatus includes a material having a good heat conductivity like aluminum alloy. Its connecting terminal is directed towards the passenger compartment and as a result the electrical connection with the wiring harness of the passenger compartment becomes easy. An advantage of the present invention is to be able to shorten the length of wiring harnesses between the engine control unit and sensors, switches and actuators of the engine, and to facilitate connections with the wiring harnesses.