Supertech Single Valve Spring Kit w/ Titanium Retainers Nissan Skyline RB25 w/ Hydraulic Lifters | SPRK-2081-RB25

Vehicle Fitment

• Nissan RB25 DOHC 24V engines
• Nissan Skyline RB25DET hydraulic lifter applications
• Nissan Skyline R33 RB25DET (non-NEO hydraulic lifter cylinder heads)

Does NOT fit:

• RB25 NEO cylinder heads
• Solid lifter conversion applications

The Supertech SPRK-2081-RB25 Single Valve Spring Kit is designed for Nissan RB25 DOHC 24-valve engines equipped with hydraulic lifters. This performance valvetrain upgrade improves valve control, reduces the risk of valve float, and provides increased reliability for modified RB25DET engines running higher RPM, increased boost, and upgraded camshaft profiles.

Engineered specifically for hydraulic lifter RB25 applications, this kit combines Supertech’s high-performance valve springs with lightweight titanium retainers and exhaust valve seat components to provide improved valvetrain stability while maintaining compatibility with hydraulic lifter cylinder heads.

Product Features

• Manufacturer: Supertech Performance
• Part Number: SPRK-2081-RB25
• Single valve spring kit
• Designed for Nissan RB25 DOHC 24V hydraulic lifter engines
• Includes valve springs, titanium retainers, and exhaust valve seats
• Lightweight titanium retainers reduce valvetrain mass
• Improves valve control at elevated RPM
• Designed for performance street and race applications
• Precision-matched valvetrain components

Kit Includes

• 24 Single Valve Springs
• 24 Titanium Retainers
• 12 Exhaust Valve Seats

Included components:

• Valve Springs: SPR-2081/RB25
• Titanium Retainers: RET-NVG1015/T1
• Exhaust Valve Seats: SS-2082-E

Note: OEM intake valve seats are required and are not included.

Valve Spring Specifications

• Spring Type: Single Spring
• Outer Spring Diameter: 27.50mm
• Inner Diameter: 20.00mm
• Seat Pressure: 85 lbs @ 30.60mm
• Open Pressure: 171 lbs @ 9mm lift
• Maximum Net Lift: 9.90mm
• Coil Bind Height: 20.70mm
• Spring Rate: 9.60 lbs/mm

Performance Benefits

• Reduces valve float at higher RPM
• Improves valve stability with upgraded camshafts
• Maintains consistent spring pressure during high-load operation
• Lightweight titanium retainers reduce valvetrain weight
• Enhances reliability in turbocharged RB25 builds
• Provides improved control during aggressive driving conditions
• Supports performance upgrades while retaining hydraulic lifter operation

Why Upgrade Your RB25 Hydraulic Lifter Valvetrain?

The factory RB25 valvetrain was designed for OEM power levels and factory operating conditions. When increasing boost, installing aftermarket camshafts, raising the RPM limit, or increasing cylinder head performance, upgraded valve springs help maintain proper valve control.

The Supertech SPRK-2081-RB25 kit is ideal for:

• Modified RB25DET engines
• Turbocharged street builds
• High-performance engine refreshes
• Track and drift applications
• Vehicles with upgraded camshafts
• Increased RPM applications