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Engine Valves / Guides / Springs

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DISPLAYING 17 to 23 (of 23 products)
1 2
99310590151/1
Product Information
Product Information
Valve spring. Porsche 993 1995-97

oematch

Fits:
Porsche 993 C2 / C4 3.6L 1994-97

Click 'Zoom in' for large parts diagram.
Diagram Ref No 13.

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Related, superseded, cross reference or alternative numbers for comparison.

99310590151
99310590151

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Special Order item
99310541700
Product Information
Product Information
Valve stem collect for inlet and exhaust valves
24 per engine.

porsche

Fits:
Porsche 993 1994-98

Click picture for large parts diagram.
Diagram Ref no 15.
99310411102/3
Product Information
Product Information
Valve stem seals.  Sold individually x12 required per engine. 

The valve stem seal, OEM part number 993 104 111 02 (sometimes superseding 993 104 111 01), is a component for the Porsche 993 series.

These seals are installed around the valve stems and serve to regulate, not entirely block, oil flow into the combustion chamber. They wipe excess oil off the valve stems and prevent undue oil burning or plug fouling. They are applicable across various 993 configurations—including the naturally aspirated Carrera and the Turbo variants—for 1994–1998 models.

Fits:
  • 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  


Why You Should Replace Them

Over time, valve stem seals, typically rubber or elastomeric, can harden, crack, or shrink, especially under high heat and engine age—which compromises their sealing effectiveness.

Visible Symptoms:

  • Blue exhaust smoke, particularly upon a cold start—leftover oil seeps past hardened seals and burns in the combustion chamber.
  • Increased oil consumption without noticeable external leaks, as oil is being burned rather than escaping visibly.
  • Smoke or puffing at idle or after deceleration, when high vacuum draws oil past failing seals.
  • Compression or misfiring issues—oil-fouled spark plugs can disrupt ignition, and carbon buildup may mimic compression loss.

Diagram ref. 8.



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Related, superseded, cross reference or alternative numbers for comparison.

99310411102
99310411102
99310411101

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Special Order item
96410546101
Product Information
Product Information
Valve stem seals washer for inlet and exhaust valves.
12 per engine

porsche

Fits:
Porsche 993 1994-98

Click picture for large parts diagram.
Diagram Ref no 11.
Special Order item
93010546100
Product Information
Product Information
Valve stem seals washer for inlet and exhaust valves.
12 per engine

porsche

Fits:
Porsche 993 1994-98

Click picture for large parts diagram.
Diagram Ref no 11.
Special Order item
99310411102
Product Information
Product Information
Valve stem seals for inlet and exhaust valves
12 per engine. Sold each.

porsche

Fits:
Porsche 993 1994-98

Click 'Zoom in' for large parts diagram.
Diagram Ref no 8.

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

99310411102
99310411101
99310411102

The product you are viewing cross references to these numbers
99310411102
Product Information
Product Information
Valve stem seals for inlet and exhaust valves
12 per engine.

victorreinz

Fits:
Porsche 993 1994-98

Click 'Zoom in' for large parts diagram.
Diagram Ref no 8.

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

99310411102
99310411101
99310411102
12-28590-01
122859001

The product you are viewing cross references to these numbers
DISPLAYING 17 to 23 (of 23 products)
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About Engine Valves / Guides / Springs

Engine Valves, Valve Guides & Valve Springs – Precision, Performance & Reliability for Porsche Engines

The valves, guides, and springs form the heart of your Porsche’s cylinder head, precisely managing airflow and combustion efficiency. Intake (inlet) valves allow the correct air-fuel mixture into the combustion chamber, while exhaust valves release spent gases. Working together with guides and springs, they ensure perfect timing, compression, and power delivery.

At Design911, we offer a comprehensive range of precision-engineered inlet and exhaust valves, valve guides, and valve springs designed for performance, durability, and exact fitment across Porsche models. Each component is manufactured from heat-resistant, high-grade steel or titanium, ensuring reliable operation under extreme conditions.

Whether rebuilding a classic air-cooled flat-six or maintaining a modern turbocharged engine, our high-quality valve components deliver the precision, strength, and sealing performance your Porsche demands.

What Do Valves, Guides & Springs Do?

These components work in harmony to control the critical air and exhaust flow that determines your engine’s power, efficiency, and longevity.

Core Functions:

  • Inlet Valves: Regulate air-fuel intake into the combustion chamber.
  • Exhaust Valves: Release burnt gases efficiently during the exhaust stroke.
  • Valve Guides: Maintain valve alignment and prevent side wear.
  • Valve Springs: Control valve movement, ensuring precise timing and closing pressure.

Together, they keep your Porsche engine breathing freely, running smoothly, and performing as designed — lap after lap, mile after mile.

Why Do Valves, Guides & Springs Fail?

Valves and related components endure extreme heat, pressure, and friction. Over time, these conditions can lead to wear, deformation, or loss of tension, affecting airflow, compression, and overall engine performance.

Common Causes of Failure Include:

  • Valve seat wear or pitting, leading to compression loss.
  • Burnt or bent valves caused by overheating or timing issues.
  • Worn valve guides, increasing oil consumption and exhaust smoke.
  • Weak or fatigued valve springs, resulting in valve float at high RPMs.
  • Corrosion and carbon build-up from poor fuel quality or short trips.

When these issues develop, symptoms may include misfires, poor performance, oil burning, or rough idling — clear indicators that replacement or overhaul is required.

Why Replace with Precision-Engineered Valve Components?

Replacing worn valves, guides, and springs ensures your Porsche engine maintains proper compression, valve timing, and airflow — all essential to reliable power delivery and fuel efficiency.

Key Benefits:

  • Restores correct airflow and combustion efficiency.
  • Improves engine compression and throttle response.
  • Prevents oil leakage and smoke caused by worn guides.
  • Eliminates valve float and restores high-RPM stability.
  • Crafted from premium heat-resistant alloys for durability and longevity.
  • Perfect fitment across classic and modern Porsche engines.

Precision-engineered components bring your engine back to its optimal condition, preserving both performance and refinement.

Highlights:

  • Comprehensive range of inlet and exhaust valves, valve guides, and springs.
  • Precision-manufactured from high-tensile, heat-treated materials.
  • Restores compression, power, and valve timing accuracy.
  • Improves reliability and reduces wear in high-performance engines.
  • Designed for rebuilds, restorations, and performance upgrades.
  • Compatible with air-cooled and water-cooled Porsche models.

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