Manley Performance Lightweight Dual Drag Race Valve Springs - 1.540 Double

- Higher natural frequency and lower active mass provides improved valvetrain control and higher RPM potential

- Dual spring design reduces friction, which generates less heat and translates into greatly reduced load loss

- Extensively tested on the Spintron, dyno and race track (including blown nitro engines) and proven highly effective

- Smaller diameter, lightweight dual design allows engine to rev higher with improved valve train control

- Accepts smaller, lighter retainers which also promotes higher revs

- Ultra clean, high tensile strength chrome silicon material

- Super Finished multi-step surface enhancement significantly improves fatigue strength

- Ideal loads for multiple applications with minimal load loss

- Alcohol &?Fuel Classes, Pro Mod

- Maximum Valve Lift 1.000

- O.D. 1.540

- I.D. .710

- Installed / Open Pressure 425 @ 2.300 / 1389 @ 1.300

- Rate (lbs/in.) 964

- Coil Bind 1.215

- Weight (grams) 154