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Tomei Valve Spring Sheets 0.5mm Mitsubishi EVO VII VIII IX 4G63 03-07



Model #TA305A-MT01C

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Tomei began operations in 1968 as a race car tuner in Japan. Over the last 40 years Japan has emerged as one of the leaders in automotive research, racing, and culture. Tomei products have been utilized in nearly every motor sport imaginable. Tomei's racing heritage means their research and design team have first hand knowledge of the extreme demands racing puts on an engine. Using only the highest quality materials means that Tomei's products can handle the intense strain and heat a purpose built engine will experience whether it be on the street or the track. Tomei's attention to detail is second to none. All of their products are thoroughly researched and engineered to achieve optimal efficiency. Because of even miniscule differences in measurements can cause catastrophic engine failure, all Tomei products fall within strict tolerances. Tomei machines all of their engine components to enhance airflow and ensure proper fitment and seal.

When installing aftermarket valve springs in a head assembly, the amount of load applied to each spring needs to be adjusted until everything so that the load applied to each spring is uniform. This is a standard procedure all race engines go through in order to be able to raise the engine RPM without any glitches or hesitation. The standard method involved when putting together the valve assembly is to fully balance all the added components to tighter clearances than the manufacturer specifications. This method called ???blueprinting??? can be a time consuming and very costly service performed by an experienced engine builder. By utilizing the various thicknesses of the spring sheets to adjust to each individual spring rate load, the same objective can be satisfied with fraction of the cost. All of Tomei's complete race engines are fitted and tuned with these valve spring sheets to ensure uniform specification for all necessary areas.


  • Smoother engine operation
  • Precise adjustments mean uniform engine wear and reliability
  • Other Part Numbers:
    Tomei #162009

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    Vehicle Engine Notes
    Mitsubishi Evolution

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