Collector/muffler/catalytic converter exhaust systems for evacuating

Abstract

An exhaust collector for use with an internal combustion engine of the type having a plurality of generally nested exhaust tubes for individually receiving exhaust gases from separate associated engine exhaust ports. The collector is frustoconically shaped and has an open upstream end sealingly engaged with the downstream ends of the exhaust tubes to receive exhaust gases directly therefrom. The collector is oriented with its generally conical shape convergent in the downstream direction, and includes an internal cone shaped stem piece oriented with its longitudinal axis coaxial of the collector. A base portion of the stem piece is nested between and extends from the downstream ends of the exhaust tubes, and an apex end of the stem piece is generally aligned with the collector downstream end. The collector interior wall defines a smooth cylindrical surface when taken in radial cross section at any position along generally the entire length of the axis of the collector downstream of the tube exit ends. Preferably, the upstream end of the collector portion is formed to conform with and securely join to the array of nested exhaust tubes. A muffler/collector combination has an outer muffler casing encircling the collector portion and encasing the same with upstream and downstream end caps. An additional embodiment provides for at least one catalytic exhaust converter positioned and arranged within a corresponding exhaust tube upstream of the collector, in combination with either the collector or the muffler collector combination. Sound absorbing material may be disposed in an interior casing space defined between the inner surface of the outer casing and the outer surface of the nested exhaust tubes and the collector.