Hydraulic Roller Cams and Solid flat tappet cams over .500" lift require a dual valve spring, meaning there is a separate outer spring, a flat damper, and then an additional inner spring inside that. This is different from "single springs" which usually include only the outer spring and sometimes the flat damper. The dual springs are required to maintain the correct spring pressure, as per most cam manufacturers recommendation. We carry these Dual Springs for all our Hydraulic ROLLER cams and SOLID flat tappet cams up to .650" lift. Use these springs together with our 145-1003 10 degree Retainers, and our 145-1002 10 degree Locks for a perfectly matched valvetrain setup. Due to the small inner diameter of the inner springs, these require using reduced diameter teflon type "PC" valve seals, use our part number 101-1049, as well as our special inner spring locator shims, part number 145-1015. Will not work with the stock black rubber type seals which are supplied on our Stealth heads, since they are too large of a diameter. This part number is for a full set of 16 valve springs. These are the same springs used on our Dual Spring Stealth Heads, part numbers 200-1201 and 200-1202.
Valve Spring Type: | Double Spring with Damper for most all flat and roller cams from .500"-.650" lift. We always recommend checking your cam manufacturer's recommendation for matching valve springs, locks and retainers. |
Valve Spring Closed (seat) Pressure: | Approx. 130 pounds @ 1.875" installed height |
Valve Spring Open Pressure | Approx. 374 pounds @ 1.225" (.650" lift.) |
Spring Pressure @ 1.800" | Approx. 158 pounds |
Spring Pressure @ 1.700" | Approx. 195 pounds |
Spring Pressure @ 1.600" | Approx. 233 pounds |
Spring Pressure @ 1.500" | Approx. 270 pounds |
Spring Pressure @ 1.400" | Approx. 308 pounds |
Spring Pressure @ 1.300" | Approx. 345 pounds |
Spring Pressure @ 1.200" | Approx. 383 pounds |
Inner Valve Spring Inner Diameter: | .780" |
Valve Spring Coil Bind Height: | Under 1.000" |
Valve Spring Outer Diameter: | 1.520" |
Valve Spring Free Height | 2.300" |
Valve Spring Installed Height: | 1.875" |
Valve Spring Wire Diameter: | .195" |
Valve Spring Number of Coils: | 5 |