RPM Series Beehive Valve Spring Set

The PAC Racing Springs PAC-1219X is an RPM Series beehive valve spring set engineered to improve valvetrain stability in high-performance engines. By utilizing ovate wire geometry and a reduced-mass design at the top coil, these springs allow for the use of smaller, lighter retainers. This design helps minimize seat pressure while increasing lobe acceleration rates and extending the usable RPM range for both street and strip applications. Technically, these springs provide a spring rate of 340 lbs/in and a maximum recommended valve lift of 0.625 inches. Key specifications include an installed height of 1.800 inches at 145 lbs of pressure, with open pressures reaching 358 lbs at 1.175 inches. The coil bind height is 1.100 inches, and the springs feature an outer diameter of 1.307 inches at the large end. Proper installation requires careful verification of your engine's valvetrain geometry, as these springs are typically paired with specific retainers (such as CCA-795-16) and locators (such as CCA-4705-16). Professional installation or measurement using a valve spring height micrometer is recommended to ensure correct setup and prevent coil bind. This kit is widely used across various platforms, including GM Gen III/IV LS engines and other performance applications.