Norris HD Single Valve Springs with Spring Dampeners MADE IN USA
Norris single HD valve springs with spring dampeners are an excellent choice when a lightweight valvetrain is in order and longevity and reliability are of utmost importance. The inner spring dampener is composed of a spring coiled backward that counteracts the harmonic vibration effect that a normal single spring suffers from. It has been proven that use of an inner spring dampener can double the life of a valve spring. Best yet? No machining required to install on stock cylinder head!
Usually, you'll use these up to 5500 RPM's... more if shimmed properly, the correct cam profile, and lightweight components are used.
Springs rated at 110 lbs @ 1.055" installed height.