An improved intake system for an internal combustion engine is disclosed which includes a combustion chamber, an intake passage and an exhaust passage opening to the combustion chamber, and an intake valve and an exhaust valve disposed in the intake and exhaust passages for opening and closing thereof....http://www.google.fr/patents/US4483282?utm_source=gb-gplus-shareBrevet US4483282 - Intake system of an internal combustion engine
