234929 Fits 1977 1984 Shovelhead 1984 2000 Evolution Big Twin Breat

This S&S Cycle steel breather valve is a precision-made component designed to optimize crankcase breathing in Big Twin engines. It fits a wide array of Harley-Davidson models, including Dyna, FXR, Softail, and Touring bikes. This steel valve is an excellent replacement for the stock steel units found in 1936–1989 engines or as a durable upgrade for the plastic valves used in 1990–1999 models. Proper breathing is vital for engine health, as it helps manage internal pressure and prevents oil leaks and carry-over. S&S builds these valves to tight tolerances to ensure reliable performance and consistent timing. Whether you’re refreshing a classic Shovelhead or building a stout Evolution, this breather valve is a key part of a well-sealed and efficient engine.