1511ML Single Beehive Valve Springs for Gen III/IV LS

The PSI 1511ML valve springs are engineered for high-performance Gen III/Gen IV LS engines, featuring a lightweight, nitrided single beehive design. This nitriding process, conducted in-house, increases the wire's surface strength while slightly softening the core, improving endurance for applications like Circle Track and Road Racing where fatigue is a concern. The springs are optimized for engines with lightweight valves, such as LS6 and LS7, to maintain control at higher lifts. With a maximum lift capability of 0.625 inches, these springs provide 130 lbs of seat pressure at 1.800 inches and 370 lbs of open pressure at 1.175 inches. The outer diameter is 1.290 inches and the inner diameter is 0.630 inches, with a coil bind at 1.100 inches. The nitriding process makes them particularly beneficial for endurance racing, though drag racers not limited by endurance may not see the same benefit from the core material's altered hardness. These springs are specifically designed to work with LS, LT1, L83, and LT4 engines, and require proper hardware for installation. Katech recommends a coil bind clearance of 0.050 inches, allowing for valve lift heights up to 0.650 inches. They are offered as a set of 16.