Built to Rev: OEM vs STK Dual Racing Valve Springs

Why Valve Springs Matter More Than You Think

Valve springs play a critical role in engine reliability and performance. Their job is simple but vital: keep the valves firmly seated and under control as engine speed increases. When valve control is lost, power drops—and serious engine damage can follow.

For standard daily driving, factory (OEM) valve springs do their job well. But once you introduce higher RPMs, aggressive camshafts, or forced induction, OEM springs quickly become a weak point.

The Limits of OEM Valve Springs

OEM valve springs are engineered for comfort, efficiency, and longevity at factory RPM ranges. They are not designed for performance driving or racing conditions.

Common issues with OEM springs in modified A14 and A15 engines include:

  • Valve float at higher RPM

  • Inconsistent valve timing

  • Reduced power in the upper rev range

  • Increased risk of valve-to-piston contact

  • Premature valvetrain wear

As engine speed rises, OEM springs simply don’t have enough seat pressure to keep the valves under control.

What Makes STK Dual Racing Valve Springs Different

STK Dual Racing Valve Springs are built specifically for performance-focused Nissan A-series engines. The dual-spring design provides increased seat pressure and improved stability, even under extreme operating conditions.

Key advantages include:

  • Superior valve control at high RPM

  • Reduced valve float

  • Improved camshaft performance

  • Increased reliability under boost or aggressive cams

  • Consistent performance across the rev range

The inner and outer spring combination works together to maintain precise valve movement, ensuring your engine can safely rev harder and breathe better.

Designed for Performance Builds

Whether you’re running a fast street setup, track car, or boosted application, STK Dual Racing Valve Springs are engineered to handle the demands that OEM parts cannot.

They are ideal for:

  • Performance camshafts

  • Raised rev limits

  • High-compression builds

  • Turbo or supercharged setups

  • Track and motorsport use

Instead of waiting for valve float or mechanical failure, upgrading your valve springs early protects your engine and unlocks its full potential.

OEM vs STK – The Real Difference

 

Intended Use

Daily driving

Performance & racing

High RPM Stability

Limited

Excellent

Valve Float Resistance

Low

High

Camshaft Compatibility

Stock only

Performance cams

Boost Compatibility

Not recommended

Designed for boost

Final Verdict

If your Nissan A14 or A15 engine is anything more than stock, OEM valve springs are holding you back. STK Dual Racing Valve Springs deliver the control, strength, and reliability needed for serious performance builds.

When you’re pushing higher RPMs, upgrading isn’t optional—it’s essential.