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Porsche // 993 (911) (1994-1998) // 993 (911) TURBO 1994-96
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Inlet valve guide 1st oversize. Porsche 993 1994-98 - 99310432271
99310432271/1
Vehicle Group
- 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
Information
Exhaust valve guide 1st oversize.
This is a replacement intake valve guide - the small, cylindrical bushing within the cylinder head that guides the intake valve stem, ensuring correct alignment and smooth, controlled movement as the valve opens and closes. In some rebuild or re-machining scenarios, oversized guides are used to restore proper fit after head work.
Price is for each, 6 required per engine.
Fits:
Porsche 993 1994 - 1998
Diagram Ref no 3.
• Use Cases: Head rebuilds; valve-seat re-cut; restoring compressed guide bores; upgrading worn or damaged valve guides; preventive maintenance where valve guide integrity is uncertain.
• Supplied individually - multiple guides needed per head depending on engine (one per intake valve).
This valve guide keeps the intake valve moving in perfect alignment, ensuring proper sealing, efficient combustion, and stable engine performance. It supports the valve stem to prevent wobble or side movement that can cause uneven seat wear or loss of compression. Designed to withstand high RPM and heat, it promotes smooth valve operation and protects the valve, seat, and cylinder-head surfaces. As an oversize guide, it also restores correct fit in worn or re-machined heads, ensuring a safe and reliable rebuild.
Valve guides endure constant thermal cycles, valve-spring force, and high-speed motion. Over time they can wear, enlarge, or become loose - causing:
• Valve wobble and mis-alignment
• Poor sealing at valve seats - resulting in compression loss, misfires, or exhaust leakage
• Increased valve-stem wear, potential seat damage, or premature engine wear
• Reduced engine efficiency, elevated emissions, and unsafe reliability.
Replacing worn or oversized guides with a proper unit restores correct valve operation, extends cylinder-head life, ensures compression integrity, and brings the engine back to spec - critical for performance, reliability, and longevity.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310432271
The product you are viewing cross references to these numbers
This is a replacement intake valve guide - the small, cylindrical bushing within the cylinder head that guides the intake valve stem, ensuring correct alignment and smooth, controlled movement as the valve opens and closes. In some rebuild or re-machining scenarios, oversized guides are used to restore proper fit after head work.
Price is for each, 6 required per engine.
Fits:
Porsche 993 1994 - 1998
Diagram Ref no 3.
• Use Cases: Head rebuilds; valve-seat re-cut; restoring compressed guide bores; upgrading worn or damaged valve guides; preventive maintenance where valve guide integrity is uncertain.
• Supplied individually - multiple guides needed per head depending on engine (one per intake valve).
This valve guide keeps the intake valve moving in perfect alignment, ensuring proper sealing, efficient combustion, and stable engine performance. It supports the valve stem to prevent wobble or side movement that can cause uneven seat wear or loss of compression. Designed to withstand high RPM and heat, it promotes smooth valve operation and protects the valve, seat, and cylinder-head surfaces. As an oversize guide, it also restores correct fit in worn or re-machined heads, ensuring a safe and reliable rebuild.
Valve guides endure constant thermal cycles, valve-spring force, and high-speed motion. Over time they can wear, enlarge, or become loose - causing:
• Valve wobble and mis-alignment
• Poor sealing at valve seats - resulting in compression loss, misfires, or exhaust leakage
• Increased valve-stem wear, potential seat damage, or premature engine wear
• Reduced engine efficiency, elevated emissions, and unsafe reliability.
Replacing worn or oversized guides with a proper unit restores correct valve operation, extends cylinder-head life, ensures compression integrity, and brings the engine back to spec - critical for performance, reliability, and longevity.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310432271
99310432271
The product you are viewing cross references to these numbers
Price: £15.00
In stock
Also found on these pages
Related products
Vehicle Group
- 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
Information
Valve spring
Fits:
Porsche 993 C2 / C4 3.6L 1994-97
Click 'Zoom in' for large parts diagram.
Diagram Ref No 13.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310590151
The product you are viewing cross references to these numbers
Fits:
Porsche 993 C2 / C4 3.6L 1994-97
Click 'Zoom in' for large parts diagram.
Diagram Ref No 13.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310590151
99310590151
The product you are viewing cross references to these numbers
Price: £53.18
In stock
Vehicle Group
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) TURBO S 1994-97
Information
Engine Cylinder Head Inlet Valve.
The OE Match Engine Cylinder Head Inlet Valve is a high-quality replacement valvetrain component designed to regulate the flow of air and fuel into the combustion chamber. Manufactured to OE specifications for fit, precision and durability, this inlet valve is essential for maintaining efficient combustion, engine performance and long-term reliability.
Fits:
Diagram Ref No 9
Constructed from premium-grade materials engineered to withstand continuous operation and high engine temperatures, the inlet valve works in conjunction with the camshaft, valve springs, valve guides and cylinder head assembly to control intake airflow with precise timing. Proper valve operation ensures optimal cylinder filling, efficient combustion and the responsive performance expected from a Porsche engine.
What This Product Does:
Symptoms Of Wear Or Failure:
Why Replacement Matters:
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310540902
The product you are viewing cross references to these numbers
The OE Match Engine Cylinder Head Inlet Valve is a high-quality replacement valvetrain component designed to regulate the flow of air and fuel into the combustion chamber. Manufactured to OE specifications for fit, precision and durability, this inlet valve is essential for maintaining efficient combustion, engine performance and long-term reliability.
Fits:
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) TURBO S 1994-97
Diagram Ref No 9
Constructed from premium-grade materials engineered to withstand continuous operation and high engine temperatures, the inlet valve works in conjunction with the camshaft, valve springs, valve guides and cylinder head assembly to control intake airflow with precise timing. Proper valve operation ensures optimal cylinder filling, efficient combustion and the responsive performance expected from a Porsche engine.
What This Product Does:
- Controls the intake of air and fuel into the combustion chamber.
- Opens and closes in precise synchronisation with the engine cycle.
- Maintains an effective seal during compression and combustion.
- Supports efficient airflow and cylinder filling.
- Helps maximise engine power and throttle response.
- Contributes to fuel economy and emissions control.
- Forms a critical part of the engine valvetrain system.
Symptoms Of Wear Or Failure:
- Reduced engine power and acceleration.
- Rough idle or uneven engine operation.
- Engine misfires.
- Poor throttle response.
- Increased fuel consumption.
- Low compression in the affected cylinder.
- Difficulty starting the engine.
- Ticking or tapping noises from the cylinder head.
- Engine management warning lights or fault codes.
- Failed compression or leak-down test results.
Why Replacement Matters:
- Inlet valves operate continuously under demanding conditions and are subjected to thousands of opening and closing cycles every minute. Over time, exposure to heat, combustion deposits and mechanical wear can cause valves to become worn, bent, burnt, carbon-contaminated or develop sealing issues.
- A damaged inlet valve can restrict airflow into the combustion chamber, reducing combustion efficiency and negatively affecting engine performance. If left unresolved, valve-related problems can lead to compression loss, increased fuel consumption and potential damage to valve seats, cylinder heads and other internal engine components.
- Replacing a worn or damaged inlet valve restores proper airflow, improves combustion efficiency and helps maintain optimal engine performance. An OE Match replacement provides factory-style fitment, precision manufacturing and long-term durability, ensuring reliable operation and helping protect your Porsche engine from premature wear and costly repairs.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310540902
99310540902
993.105.409.02
3310.239
854429-6
The product you are viewing cross references to these numbers
Price: £27.00
In stock
Vehicle Group
- 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
Information
Valve stem seals for inlet and exhaust valves
12 per engine. Sold each.
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
The product you are viewing cross references to these numbers
12 per engine. Sold each.
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
Price: £5.87
In stock
Vehicle Group
- 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
Information
Valve stem seals washer for inlet and exhaust valves.
12 per engine
Fits:
Porsche 993 1994-98
Click picture for large parts diagram.
Diagram Ref no 11.
12 per engine
Fits:
Porsche 993 1994-98
Click picture for large parts diagram.
Diagram Ref no 11.
Price: £3.63
In stock