TWO CYCLE ENGINE WITH EXHAUST BRIDGE LUBRICATION

摘要

In a two cycle internal combustion engine , a fuel-air flow passage and reservoir is provided along the exhaust bridge and between the piston and the cylinder inner wall for lubricating the exhaust bridge . The piston has a flat spot machined on its side wall to form an axially extending flow passage and reservoir closed at its top end by the piston rings and at its bottom end by a lower portion of the piston side wall which is not machined and which is closely adjacent the cylinder inner wall . When the piston is in its power stroke, crankcase pressure forces fuel-air mixture through holes in the piston side wall at the flat surface into the flow passage and reservoir . If the exhaust bridge heats and expands into the cylinder , the piston will not rub on it.