Recently R&D revealed the new set of valve springs that has been designed to use along with the new set of 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 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 with stock retainers during the 2009 season and have proven their performance with an APBA/IJSBA Pro Open National Championship. R&D dual springs are a lightweight design and manufactured from ultra clean, high tensile material with multi step surface treatments to improve fatigue strength and reliability. NOTE: R&D Spring Kits must use the R&D Bottom Spring Retainer Cups. The new springs, retainer cups, oil seals and shims are already available from R&D.
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>R&D spring valves for 300X
















