Accurate valve spring load is critical for stable high-RPM operation on Nissan RB-series engines. The Tomei Valve Spring Seat Set (part number TA305A-NS05C) provides a 0.5 mm thickness option in a set of eight seats, giving builders a more substantial adjustment step when setting installed spring height and restoring correct seat pressure.
After a valve job or when installing aftermarket valve springs, the effective spring height can change enough to drop seat load below the intended specification. These 0.5 mm precision seats allow a larger correction than the thinner options, helping bring spring pressure back into the proper range and supporting consistent valve control. The set is designed for use on RB26, RB25, and RB20 cylinder heads where uniform spring loads are required for reliable high-RPM performance.
At Terra Firma Automotive, we supply this genuine Tomei 0.5 mm Valve Spring Seat Set for engine builders working on Skyline and other RB-powered platforms. Whether you are assembling a performance cylinder head or compensating for machining changes, these seats offer a straightforward and effective method for achieving the correct spring geometry. Choose Terra Firma Automotive for authentic Tomei components that support precise head assembly work.
- Genuine Tomei Valve Spring Seat Set
- Part Number: TA305A-NS05C
- Thickness: 0.5 mm
- Quantity: 8 pieces
- Application: Nissan RB26 / RB25 / RB20 series
- Used to adjust valve spring installed height
- Provides a larger correction step than thinner seats
- Helps restore correct spring load after machining
- Supports consistent valve control at high RPM
- Ideal for use with aftermarket valve springs
- Useful for performance cylinder head setups
- Prevents reduced seat pressure from valve jobs
- Simple and effective adjustment solution
- Trusted Japanese performance component
- Available from Terra Firma Automotive
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