When you're pushing a BMW S63 or N63 beyond factory limits, valve control stops being a detail and starts being survival. This VAC Motorsports High-Performance Valve Spring Kit is engineered to keep your valvetrain stable when RPM climbs, boost rises, and mistakes--like a missed downshift--are no longer theoretical.
Designed, tested, and manufactured in the USA, this kit delivers the added margin of safety serious builds demand, whether you're running mild upgrades or aggressive cam profiles.
Why This Kit Matters
Modern BMW V8s don't fail gracefully at high RPM. Valve float, over-rev events, and unstable valvetrain geometry can turn an expensive build into scrap metal in seconds. These springs and titanium retainers are built to hold the line--cleanly, consistently, and reliably.
This is not about chasing a number on paper. It's about control.
Key Features & Benefits
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High-performance dual valve springs engineered for high-RPM stability
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Lightweight titanium retainers reduce valvetrain mass
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Adds a critical safety margin against over-revving or mis-downshifts
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Designed for maximum long-term reliability
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Fully compatible with all performance camshafts
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Capable of handling both mild and aggressive cam profiles
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Shot-peened for stress relief and extended fatigue life
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Precision manufactured in the USA
Technical Specifications
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Seat Pressure: 83 @ 35.7mm
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Open Pressure: 165 @ 10mm
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Spring Rate: 8.2
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Maximum Valve Lift: 11.2mm
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Coil Bind: 23.00mm
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Outer Spring OD: 24.00mm
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Outer Spring ID: 17.20mm
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Inner Spring OD: 21.00mm
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Inner Spring ID: 14.20mm
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Retainers: Titanium
Ideal For
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High-boost S63 and N63 builds
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Track-driven or aggressively street-driven cars
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Engines running upgraded or aftermarket camshafts
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Builders who want reliability without compromise
VAC Engineering Philosophy
VAC Motorsports components are designed for engines that actually get used--hard. This valve spring kit reflects decades of real-world engine building experience, not theory. Every spec here exists to protect your investment when conditions stop being ideal.
If you're already inside the engine, this is the upgrade that quietly saves you thousands later.