S&S Cycle S&S BT93-99 style breather reed valve

Tuotenumero 750586

199,63 € · tilaustuote

Patent pending reed valve crankcase breather from S&S that really helps to resolve oil carry over problems in Evolution Big Twin engines. Unlike the rotary breather valve that has been used in Big Twin engines since the 1930's, the S&S crankcase breather reed valve is not dependent on the rotation of the crankshaft to make it open and close. Therefore the opening and closing times are not determined by crankshaft position. Instead, the reeds open when the pressure in the crankcase becomes greater than the pressure in the cam chest. The reeds then close when the pressure in the cam chest is equal to or greater than the pressure in the crankcase. The difference in the way these breather valves function is important because the ideal breather timing actually changes with rpm and the condition of the engine. By opening and closing "on demand" the reed valves automatically compensate for the lag time associated with accelerating the mass of air as it is forced out of the crankcase. This is most significant at high rpm when the time available to get the air out is the shortest. In addition, "on demand" operation allows reed valves to accommodate greater amounts of compression blo