Exhaust gas discharge system for two-stroke internal combustion engine

USRE34764E · kind E · reissue

Assignee

• Outboard Marine Corporation · US

Inventor

• Alan Blair · Launceston, AU

Key dates

• Filing date: Apr 2, 1993
• Grant date: Oct 25, 1994
• Expiry date: Apr 2, 2013

Classification

• Technology area (CPC —): General

Abstract

Disclosed herein is a two stroke internal combustion engine comprising first, second, third, and fourth cylinders which fire in a predetermined sequence and which include respective first, second, third, and fourth exhaust ports which open and close in response to piston movement, and an exhaust gas discharge system communicating with the exhaust ports, including a duct portion, and being operable, in response to opening of one of the exhaust ports, to afford passage of exhaust gas from the one exhaust port to the exhaust gas discharge system so as to provide an outgoing positive acoustical pressure wave which travels in the duct portion and which arrives at the exhaust port of the previously fired cylinder prior to closure of the exhaust port of the previously fired cylinder and to provide a returning negative acoustical pressure wave which travels in the duct portion after substantial completion of the travel of the outgoing positive acoustical pressure wave in the duct portion and which arrives at the one exhaust port prior to closing of the one exhaust port.