New set of double valve springs and retainers to go with aggressive Schrick cams on S54 engines used in E46 M3, MZ3, and E85/E86 Z4M models.

Set includes:
24 x 041502095, inner & outer valve spring
24 x 041513011, upper retainer (Titanium)
24 x 041513012, lower spring seat (steel)

The Schrick S54 springs are a dual-spring design, using an inner and outer spring. The main reason for new springs is to use a stiffer spring and prevent valve-piston contact with the extra lift from these cams. The dual design has the additional benefit of controlling spring behavior and frequency, especially at high RPM, as well as providing a fallback in the unlikely occurrence of a broken spring (prevents the valve from dropping or floating). Top retainers are made from Titanium.