ARRANGING STRUCTURE OF DOUBLE POPPET VALVE

摘要

PURPOSE: To shorten the maximum lift distance of three or more intake poppet valves that needs to be equal or approximate to the cross-sectional area of a single intake duct, with which these valves are used, by setting the total circumference of these valves at least one-point-four times as long as the circumference of the duct. CONSTITUTION: Four intake poppet valves 11 are arranged in a symmetrical relation about the axis of a single intake duct 14. The cross-sectional area of the intake duct 14 is predetermined so as to equate with the total area of valve ports 17 substantially. If a plurality of valves 11 of the same area are used, the total contour length of these valves 11 or ports 17 is set at least one-point-four times as long as the contour length of an existent single valve set in a single port opening cut in a cylinder head 22. This arrangement shortens the lift distance of these valves 11 that allows the single duct 14 to deliver its maximum possible flow rate of intake air for a longer period.