PAC-1371-16 0.716 in. ID – 1.374 in. OD – 1.950 in. installed Height – 0.700 in. Max Valve Lift

0.716 in. ID – 1.374 in. OD – 1.950 in. installed Height – 0.700 in. Max Valve Lift PAC Racing’s 1300 Series Drag Race Dual Valve Spring is the manifestation of the latest technology in the drag racing valvetrain aftermarket. Traditional springs were made with higher loads and rates without concern of spring mass and frequency. PAC Racing has taken years of research and coupled that with exotic new heat treatment methods to produce the next generation of drag racing valve springs. The 1300 Series springs feature a 15-30% reduction in physical mass. This, coupled with a natural frequency increase of 20%, enables your engine to rev higher, faster, and last longer even with aggressive camshaft profiles. These springs are constructed of our signature PACaloy super clean wire and are heat-treated in-house for precise spring rates and enhanced strength. They undergo a multi-peen process to optimize service life as well. Unique to the 1300 Series, these springs then receive ID/OD chamfer finishing, a run through the polisher, and a Nano-Peen™ proprietary surface treatment to improve operating cycles. Built using our signature PACaloy super clean wire to ensure strength and durability In-house heat-treating for precise spring rates and increased strength Multi-peen process to optimize service life ID/OD chamfer finishing Polishing to improve operating cycles Nano-Peen™ Proprietary Surface Treatment Outer Diameter – Outer Valve Spring 1.374 IN Inner Diameter – Outer Valve Spring 1.000 IN Inner Diameter – Inner Valve Spring 0.716 IN Installed Height 1.950 IN Installed Load 150 PS Open Height 1.250 IN Open Load 455 PS Open Load / Height (Valve Open) 455 LB @ 1.250 IN Valve Spring Rate 436 PS Max Coil Bind 1.190 IN Max Valve Lift 0.700 IN Recommended Valve Spring Retainer – 300 Series R317, R348 Recommended Valve Spring Retainer – 500 Series R517, R552 Recommended Valve Spring Seat S114, S115 Valve Spring Series 1300 Series Valve Spring Type Dual Valve Spring Application Circle Track Primary Market Circle Track|Street Performance