Dual Valve Springs with Damper, 1.538" OD, 436 lbs/in

The Trick Flow® by PAC Racing Dual Valve Springs, part number TFS-16929-16, are engineered to meet rigorous performance standards. Manufactured from high tensile-strength Pacaloy™ chrome-silicon steel, these springs are double shot-peened to exceed Aerospace Material Specifications (AMS) reliability criteria, ensuring exceptional durability and longevity. They feature a 1.538-inch outside diameter, a 1.140-inch inside diameter for the outer spring, and a 0.752-inch inside diameter for the inner spring. The spring rate is rated at 436 lbs./in., with a coil bind height of 1.090 inches. Performance specifications include a seat pressure of 157 lbs. at an installed height of 1.850 inches and an open pressure of 440 lbs. at an open height of 1.200 inches. These springs are designed to support a maximum valve lift of 0.650 inches. A damper spring is included to provide extra surge prevention, crucial for high-revving applications. This set is sold as a quantity of 16, enough for a complete engine build.