Motorcycle exhaust system

For use with an engine having at least two engine cylinders firing in an alternating sequence, an exhaust system comprising:

• a pair of exhaust conduits each having an inlet end connected to a different one of the engine cylinders for receiving exhaust gases discharged therefrom for passage through said conduits to atmosphere;
• a crossover pipe joined to each of said exhaust conduits by curved shoulders and defining an open flow path between said exhaust conduits, said shoulders serving to guide smoothly exhaust gas flow from one of said exhaust conduits into said crossover pipe, and further from said crossover pipe into the other of said exhaust conduits;
• and
• a pair of flow dividers mounted respectively within said exhaust conduits generally adjacent the inlet ends thereof, each of said flow dividers being disposed for dividing exhaust gases flowing through the associated exhaust conduit into two substantially equal flow portions, and including at its downstream end an arcuately-shaped portion extending generally toward the crossover pipe generally concentrically with respect to the adjacent curved shoulder for guiding one of the gas flow portions for flow through said crossover pipe to the other exhaust conduit, whereby exhaust gases from the engine flow at all times in substantially equal portions through both of said exhaust conduits.

For use with an engine having at least two engine cylinders firing in an alternating sequence, an exhaust system comprising:

• a pair of exhaust conduits each having an inlet end connected to a different one of the engine cylinders for receiving exhaust gases discharged therefrom for passage through said conduits to atmosphere;
• a crossover pipe joined at opposite ends to each of said exhaust conduits by curved shoulders and defining an open flow path between said exhaust conduits defining an open flow area of about 70 percent of the open flow area of one of said exhaust conduits, said shoulders serving to guide smoothly exhaust gas flow from one of said exhaust conduits into said crossover pipe, and further from said crossover pipe into the other of said exhaust conduits;
• a pair of flow dividers mounted respectively within said exhaust conduits generally adjacent the inlet ends thereof, each of said flow dividers being disposed for dividing exhaust gases flowing through the associated exhaust conduit into two substantially equal flow portions, and including at its downstream end an arcuately-shaped portion extending generally toward the crossover pipe generally concentrically with respect to the adjacent shoulder for guiding one of the gas flow portions for flow through said crossover pipe to the other exhaust conduit, said arcuately curved portion of each of said flow dividers extending over an arcuate path of at least about 45.degree. and terminating within the associated exhaust conduit generally at the upstream extent of said crossover pipe, whereby said exhaust gases from the engine flow at all times in substantially equal portions through both of said exhaust conduits;
• and
• a pair of noise abatement mufflers mounted respectively along said exhaust conduits downstream of the connection with said crossover pipe.