Patent ID: 6381956
Filing Date: 2002-05-07
Classification: F01N,F02B,Y02T

Abstract:
An exhaust system tuned for performance for an internal combustion engine having at least two cylinders each with an exhaust port, the exhaust system comprising a single elongated exhaust pipe having a first end with at least two headers connected to the respective engine exhaust ports and a second end and at least one section between the first and second ends having a predetermined length and cross sectional area, the exhaust pipe having separate non-circular exhaust passages extending between the respective headers and the second end for conducting exhaust gases from the respective engine cylinders to the atmosphere without mixing, each exhaust passage being partially defined by an outer wall that extends between the first and second ends, and being further defined by and separated from an adjacent passage by a shared wall inside the outer wall, wherein the exhaust pipe comprises at least one first section whereat the outer wall diverges toward the exhaust pipe second end, and at least one second section between the first section and the second end whereat the outer wall converges toward the exhaust pipe second end, the outer wall at the first and second sections being so dimensioned and cooperating with the shared wall to tune a two-stroke engine for performance.