STK Performance Dual Racing Valve Spring Kit VW 8v
When you’re building a serious Volkswagen 8-valve motor, the valvetrain isn’t just another box to tick — it’s the backbone of the whole setup. High RPM, aggressive cam profiles, boost… they all demand control. And that starts with proper valve springs.
The STK Performance Dual Racing Valve Spring Kit for VW 8v engines is engineered to deliver the strength, stability, and durability required for performance applications that go well beyond factory limits.
What Is It?
This kit replaces the factory single valve springs with a high-performance dual spring design. Instead of one spring per valve, you get an inner and outer spring working together.
That dual setup dramatically improves valve control at higher engine speeds, making it ideal for:
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High-revving naturally aspirated builds
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Turbocharged or supercharged setups
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Engines running aggressive aftermarket camshafts
If your engine is operating outside stock specifications, single springs simply aren’t enough.
What’s Included
- 8 × Inner & Outer Springs
- 8 x Retainers 7mm
- 4 x Inlet Valves 40mm
- 4 x Exhaust Valves 33mm ( 3 groove )
Everything you need to properly upgrade and strengthen your valvetrain in one complete package.
Technical Specifications
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Seating Pressure (at 34 mm): ±90 lbs
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Open Pressure (Full Lift): ±200 lbs
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RPM Capability: Suitable for builds exceeding 8,500 RPM (depending on setup)
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Spring Material: Chrome-silicon alloy
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Retainers: Lightweight 4130 chromoly
These specs make the kit well-suited for aggressive street, drag, and track applications where consistent valve control is non-negotiable.
Why Dual Valve Springs Matter
As RPM climbs, so do the forces acting on your valvetrain. Factory springs can struggle to keep up, leading to valve float — when the valve fails to close fully before the next cam cycle. That’s where power loss starts… and where engine damage can follow.
Dual springs solve this by providing:
1. Improved High-RPM Stability The combined spring force keeps valves controlled and seated properly at elevated engine speeds.
2. Reduced Harmonics Because the inner and outer springs operate at slightly different frequencies, harmful harmonic vibrations are reduced. Less vibration means better durability and smoother operation.
3. Camshaft Compatibility High-lift and long-duration camshafts demand higher spring pressure. Dual springs provide the support required to run aggressive cam profiles safely.
Built for Strength and Longevity
The springs are manufactured from chrome-silicon alloy — a material known for exceptional tensile strength and fatigue resistance. It performs significantly better under heat and repeated stress than standard spring steel.
The included 4130 chromoly retainers are both lightweight and strong, reducing overall valvetrain mass while maintaining durability. Lower moving mass equals improved stability at high RPM.
Installation Notes
Professional installation is highly recommended.
Correct installed height, seat pressure, and coil bind clearance must be measured and verified. Builders should also confirm piston-to-valve clearance when using high-lift camshafts. Precision during assembly is critical to ensure long-term reliability.
Who Is This Kit For?
This kit is ideal for:
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High-revving naturally aspirated VW 8v builds
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Turbo or supercharged combinations
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Performance camshaft setups
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Track, drag, and serious street cars
If you’re pushing your VW 8-valve engine beyond factory limits, upgrading your valve springs isn’t optional — it’s essential.
Final Thoughts
The STK Performance Dual Racing Valve Spring Kit for VW 8v engines is designed for builders who refuse to compromise. With increased spring pressure, improved harmonic control, and high-strength materials, it provides the valve stability required to support serious power.
When every component in your engine matters, proper valve control isn’t just important — it’s foundational.
