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Porsche > 964 (911) (1989-1994) > 964 (911) C2 1989-93 > Engine Tuning >

Valve springs

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DISPLAYING 1 to 4 (of 4 products)
High performance valve spring, seat and retainer kit 9mm. Porsche 911 / 964 - 90110590150, 90110590151, 90110546300, 90110546303, 90110542103, 90110542104, 90110552102
6
High performance valve spring, seat and retainer kit 9mm. Porsche 911 / 964
HP109HSSKIT
Product Information
Product Information
High performance valve spring, seat and retainer kit 9mm. 

aasco

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

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 9mm titanium valve spring retainer disc x 12



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Related, superseded, cross reference or alternative numbers for comparison.

HP109HSSKIT
90110590150
90110590151
90110546300
90110546303
90110542103
90110542104
90110552102

The product you are viewing cross references to these numbers
Valve spring kit high performance. Porsche 911 / 964 / 993 - 90110590150, 90110590151, 99310590151
1
Valve spring kit high performance. Porsche 911 / 964 / 993
HP109
Product Information
Product Information
Valve spring kit - high performance. 

aasco

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Related, superseded, cross reference or alternative numbers for comparison.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
90110590150
90110590151
99310590151

The product you are viewing cross references to these numbers
Valve spring retainer disc kit 9mm Titanium high performance. Porsche 911 / 964 - 90110542103, 90110542104, 90110552102
2
Valve spring retainer disc kit 9mm Titanium high performance. Porsche 911 / 964
HP10T9
Product Information
Product Information
9mm Titanium valve spring retainer disc kit - high performance. 

aasco

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

9mm Porsche 911 titanium valve spring retainers for 9mm valves. 

Can be used to directly replace OE retainers but we recommend using in conjunction with Aasco HP109  valve springs and HPSS spring seats.

Set of 12



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Related, superseded, cross reference or alternative numbers for comparison.

HP10T9
90110542103
90110542104
90110552102

The product you are viewing cross references to these numbers
Valve spring seat kit high performance. Porsche 911 / 964 / 993 - 90110546300, 90110546303, 99310546302
1
Valve spring seat kit high performance. Porsche 911 / 964 / 993
HPSS
Product Information
Product Information
Valve spring seat kit - high performance. 

aasco

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
90110546300
90110546303
99310546302

The product you are viewing cross references to these numbers
DISPLAYING 1 to 4 (of 4 products)
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About Valve springs

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       

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