R&D has developed an economical solution for upgrading the upper valve train by offering a one stop shopping parts upgrade kit that will work great in the 8500-9000 RPM range in an economical price range. The kit includes our Super Single chrome silicone valve spring, precision machined premium grade titanium top spring retainers, and custom designed bottom spring/locator cup. The R&D Super Single Valve Spring Kit is a recreational and offshore upgrade favorite which offers great valve control and adds gimproved strength and reliability by changing out the stock steel retainers known to crack for super strong, lightweight titanium! R&D has documented that the seat tension or pressure on the O.E.M. stock springs is a low 52-55 pounds, and coil bind on the stock springs occurs .050 after full lift on the stock cams. As an industry rule or standard, as boost levels are increased to the engine, the valve spring seat pressure should be increased 1-2 pounds per pound of boost. As an industry rule, as RPM'S are increased, the spring pressure at full lift should be increased as well to reduce or eliminate valve float at high rpm frequencies. With the stock springs short lift travel shimming is NOT an option. Valve Springs and Parts MUST be upgraded. Also to consider is valve spring travel at full cam lift, and to have enough spring clearance freedom to run high performance camshafts or add additional spring tension pressures without coil bind issues. The R&D spring kit parts were developed and used during the 2009/2010 season and have proven their performance with two APBA Pro Offshore National Championships. R&D Super Single springs are a lightweight design and manufactured from ultra clean, high tensile materials with multi step surface treatments to improve fatigue strength and reliability. NOTE: R&D also offers additional bottom cup shim kits for proper seat pressures adjustments and valve travel settings. Features: 70-75 pounds at seat, 140-150 pounds at full lift (standard spec.), Shim friendly, add R&D spring collar base shims to add 2 pounds per .010 shim added, Allows the use of higher lift cams (up to +.080 more lift), Linear spring pressure curve allows smooth precision valve control, adds to overall horsepower and High performance materials and surface finishes add to reliability.
