REVTECH ADJUSTABLE BREATHER VALVE +.030 OVERSIZE O.D. WITH 10 DURATION. FITS BIG TWIN SHOVEL & EVO MODELS LATE 1977-1999. U.S. PATENT #4 869 213
Source: Custom Chrome
Permit the engine builder to alter breather timing to match the displacement of the motor. Increasing the stroke or cylinder bore changes the total volume of the crankcase. If the breather is not modified, the cylinders fight the pressure build-up in the lower end that a stock breather cannot relieve. RevTech® offers an all-steel breather valve for Big Twins from late 1977 thru 1999. It s designed to replace the stock steel or plastic breather valve and with its removable gear, permits you to dial in the exact timing needed to ensure proper scavenging. Includes a selection of four different-sized thrust washers. Fit engines from late 1977 thru 1999 (except Twin Cam 88® models).