The S&S KN420 Camshaft is a high-lift Camshaft for modified knuckle engines. Features .420 inch valve lift and increased duration for larger engines up to 93 inch and compression ratio of up to 8.5:1. Special high-lift valve springs are required. Designed to be used with solid lifters.
Fits 1936-1947 OHV big twin engines in Harley-Davidson® motorcycles and Flathead Power KN-Series engines.