Street Performance .585" Valve Spring Kit for 2005-'18 Twin Cam 88® big twins w/ stock heads (both 7mm and 5/16" valve stems) and 2004-19 XL models. Single wire conical shape. Suitable for high performance applications. Accommodates camshaft lift to 0.585”. Kit contains: Valve Guide Seals, Springs, Top & Bottom Collars, Keepers, Shims.
Use with shoulderless-style valve guides.
Special keepers included fit valves with stock 5⁄16" stems and S&S collars only.
Spring seat force is typically 170 lbs. at stock 1.800" installed height.
Open force is 390 lbs. at .560" lift, 415 lbs. at .630" lift.
May also be used in any other heads that require stock O.D. outer spring.
S&S springs will not fit 2005 - later stock heads because of the change in
valve spring and valve stem diameter.
High lift cams may require the engine builder to obtain additional clearance
between the piston and valves, the intake and exhaust valves and the upper
spring collar and rocker cover. Clearance should also be checked between
the rocker arm and valve spring collar as well as between the rocker arm and
rocker cover. It is imperative that the engine builder confirm these clearances
and check for spring coil bind, even when using parts specifically designed for
high performance. Most valve train failures can be traced to over-revving or
failure to confirm correct clearances during assembly.