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- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 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

Fits:
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.
Kit includes
High performance valve spring x 12
High performance valve spring seat x 12
High performance 8mm titanium valve spring retainer disc x 12
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
HP10T8HPSSKIT
The product you are viewing cross references to these numbers
This kit is comprised of the following items:
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 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

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Related, superseded, cross reference or alternative numbers for comparison.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
The product you are viewing cross references to these numbers
- 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
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:
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
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 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

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
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 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

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
The product you are viewing cross references to these numbers
Porsche Performance Valve Springs - High-RPM Valvetrain Control
Valve Springs are critical valvetrain components responsible for controlling valve movement, ensuring precise opening and closing at all engine speeds. In performance, tuned, or high-revving Porsche engines, upgraded valve springs are essential to maintain valve control, prevent float, and protect the engine under increased RPM and load.
Available from Design911, Porsche performance valve springs are engineered to deliver increased spring rate, improved fatigue resistance, and consistent operation—making them ideal for performance builds, engine rebuilds, and motorsport applications.
What Do Valve Springs Do?
Valve springs control valve motion and ensure accurate timing during engine operation.
Core Functions:
- Close valves quickly and securely after camshaft actuation.
- Maintain valve control at high RPM.
- Prevent valve float and bounce.
- Support accurate valve timing and combustion.
- Protect valvetrain components from excessive wear.
Proper valve spring performance is essential for safe high-speed engine operation.
Why Do Valve Springs Fail?
Standard valve springs are designed for factory RPM limits
and daily driving. Failures can occur when engines are pushed beyond these
limits due to:
- Metal fatigue from repeated high-RPM cycles.
- Valve float caused by insufficient spring pressure.
- Heat-related loss of spring tension.
- Increased camshaft lift or aggressive profiles.
- Age-related weakening in high-mileage engines.
Valve spring failure can lead to loss of power, misfires, or severe engine damage due to valve-to-piston contact.
Why Upgrade to Performance Valve Springs?
Performance valve springs are designed to maintain valvetrain control under extreme conditions.
Upgrade Benefits:
- Higher spring rates for improved valve control.
- Increased resistance to fatigue and heat.
- Supports higher RPM and aggressive camshafts.
- Essential for tuned, track, and race engines.
- Improved reliability and engine safety.
Upgrading valve springs ensures stable, precise valve operation in high-performance Porsche engines.
Highlights
- Porsche performance valve spring upgrades
- Improved valvetrain control at high RPM
- Designed for tuned and motorsport engines
- Reduces risk of valve float and engine damage
- Essential upgrade for high-revving applications