PSI, the first racing-only valve spring manufacturer in the U.S., offers the 1513ML from its 1500-series Max-Life line. It is built with advanced heat-treating processes to strengthen the base material to increase fatigue life and offer better resistance to load loss, but with an additional proprietary multi-step enhancements to further the life of the spring. These processes target the endurance applications that these springs were built for, like circle track and road racing. The ability to start and finish an event with the best spring possible to avoid not only breakage but also avoid load loss, which compromises your engine’s performance is the mindset behind this spring’s design.
Combined with quality BTR hardware, this spring package is a top-quality upgrade for hydraulic roller, stock rocker combinations looking for increased rpm capacity, and a top-quality valve-spring. When paired with lightweight hollow stem or titanium intake valves, high-performance lifters, appropriate trunnion or shaft rocker upgrade, and appropriate setup, these springs are capable of adequate valve-train control at engine speeds approaching 7,800rpm.
Spring Specifications:
- 290” O.D.
- 800” installed height
- 160lbs seat pressure
- 466lbs open pressure (@.650” lift)
- 471lbs spring rate
- .700” max lift
- 1.000” coil bind
Great product
Amazing