Valve springs

8mm titanium valve spring retainer disc - high performance



Fits:
Porsche 993 - 1994 to 1998

8mm Porsche 911 Titanium Retainers for 993 1995-1998 for 8mm valves.

Please note
Must be used in conjunction with Aasco HP109-Valve Springs and HPSS Spring Seats. 

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

HP10T8

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Mechanical Rocker Arm Conversion Set - High-Performance Valve Train Upgrade

The Mechanical Rocker Arm Conversion Set is a precision-engineered valve train upgrade for Porsche 993, 993 Turbo and GT2 engines. This conversion replaces the original hydraulic lifter system with a mechanical rocker arm setup featuring oil-lubricated rocker shafts, delivering improved valve control, reliability, and performance at high engine speeds.

Fits:

• Porsche 993 (911) C2 1994-97
• Porsche 993 (911) C4 1994-97
• Porsche 993 (911) C2S 1994-97
• Porsche 993 (911) C4S 1994-97
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97  

Designed for high-performance road, motorsport, and track-focused engines, this conversion eliminates the limitations associated with hydraulic lifters, particularly under sustained high RPM and extreme thermal loads. By adopting mechanically actuated rocker arms with direct oil lubrication, engine builders gain greater consistency, improved durability, and enhanced camshaft control.

This system is widely used in competition builds, high-output street engines, and applications where precise valve timing and stability are critical.

What Does the Mechanical Rocker Arm Conversion Do?

This conversion fundamentally improves how the valve train operates under load.

Core Functions:

• Replaces hydraulic lifters with mechanically actuated rocker arms.
• Provides direct, oil-lubricated rocker shaft operation.
• Improves valve control and timing accuracy at high RPM.
• Reduces valve float and lifter pump-up issues.
• Enhances reliability in high-performance and motorsport applications.

By removing hydraulic compensation, the valve train responds more precisely to camshaft profiles, making this conversion ideal for aggressive cam setups and sustained high-speed operation.

Why Do Hydraulic Valve Train Components Fail?

Hydraulic lifter systems are designed for comfort and noise reduction, but they become a limitation in high-performance environments.

Common Failure or Limitation Causes Include:

• Lifter pump-up at high RPM, causing valve float.
  
• Oil aeration or pressure fluctuations, reducing lifter effectiveness.
  
• Thermal breakdown, leading to inconsistent valve timing.
  
• Wear or collapse of hydraulic elements over time.
  
• Reduced reliability under track or motorsport conditions.

These issues can compromise performance, cause misfires, or lead to accelerated valve train wear.

Why Replace or Upgrade to a Mechanical Rocker Arm System?

Upgrading to a mechanical rocker arm system provides a robust, performance-focused solution for demanding engines.

Key Benefits:

• Consistent valve operation at high engine speeds.
• Improved durability compared with hydraulic systems.
• Oil-lubricated rocker shafts for reduced friction and wear.
• Ideal for high-lift or motorsport camshaft profiles.
• Enhanced throttle response and power delivery.
• Proven solution for track, race, and high-output road engines.

This conversion is a cornerstone upgrade for Porsche 993-based performance engines where reliability and precision are paramount.

Highlights
Mechanical rocker arm conversion for Porsche 993, 993 Turbo & GT2.
Oil-lubricated rocker shafts for superior durability.
Eliminates hydraulic lifter limitations.
Designed for high-RPM and motorsport use.
Improves valve timing accuracy and stability.
Suitable for performance builds, restomods, and race engines.       

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

FVD105399

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Valve spring kit - high performance. 



Fits:
Porsche 911 - 1965 to 1989
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1998

Our Valve Springs are designed and manufactured to specifically fit the envelope of a Porsche application not a spring from another use. 

It operates a higher natural frequency than the original spring for racing and at the very least minimizes damage from over rev in track day situations. 

Please note
993 - must use 8mm Ti retainers and Aasco Seats

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

HP109

The product you are viewing cross references to these numbers

Valve spring seat kit - high performance. 



Fits:
Porsche 911 - 1965 to 1989
Porsche 964 - 1989 to 1994
Porsche 993 - 1994 to 1998

Our Steel Spring Seats pocket the inner spring of our Aasco High Performance Valve Springs.

Our Valve Springs are designed and manufactured to specifically fit the envelope of a Porsche application not a spring from another use. 

It operates a higher natural frequency than the original spring for racing and at the very least minimizes damage from over rev in track day situations. 

Please note
993 - must use 8mm Ti retainers and Aasco Seats

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

HPSS

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