Please wait… 
Please wait while we process your order,
do not press the back button…
do not press the back button…
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
Category Filter
Valve stem seals. Porsche 993 1994-98 - 99310411102
99310411102
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Related, superseded, cross reference or alternative numbers for comparison.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Related, superseded, cross reference or alternative numbers for comparison.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: €5.93
In stock
Related products
Vehicle Group
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 914 (1970-1976)
Information
Cylinder Head Intake Valve.
Maintain the performance and reliability of your classic Porsche engine with this OE Match cylinder head intake valve. Designed to precisely replicate the original Porsche specification, this valve ensures proper airflow, sealing, and combustion efficiency in early air-cooled engines.
Fits:
Porsche 911 S/TU/T/E 1965 - 1969
Porsche 914-6 1970 - 1976
Diagram ref no 9.
Manufactured from high-grade, heat-resistant steel alloy, it delivers outstanding strength, thermal stability, and wear resistance — essential for the demanding environment of Porsche’s horizontally-opposed engines. Each valve is precision-ground for perfect seat contact, ensuring smooth intake flow, consistent compression, and long-term durability.
Function:
The intake valve allows the precise entry of the air-fuel mixture into the combustion chamber. Properly sealing valves are critical for maintaining compression, fuel efficiency, and smooth idle. A high-quality OE Match valve ensures exact timing, optimal airflow, and factory-level performance across the rev range.
Why & When Replacement Matters
Why:
Continuous exposure to heat, carbon build up, and mechanical stress can cause valve face wear, pitting, or bending, leading to loss of compression, rough running, and reduced power.
When:
Replacing with an OE Match intake valve restores engine efficiency, reliability, and preserves the authentic performance character of your classic Porsche.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110540700
The product you are viewing cross references to these numbers
Maintain the performance and reliability of your classic Porsche engine with this OE Match cylinder head intake valve. Designed to precisely replicate the original Porsche specification, this valve ensures proper airflow, sealing, and combustion efficiency in early air-cooled engines.
Fits:
Porsche 911 S/TU/T/E 1965 - 1969
Porsche 914-6 1970 - 1976
Diagram ref no 9.
Manufactured from high-grade, heat-resistant steel alloy, it delivers outstanding strength, thermal stability, and wear resistance — essential for the demanding environment of Porsche’s horizontally-opposed engines. Each valve is precision-ground for perfect seat contact, ensuring smooth intake flow, consistent compression, and long-term durability.
Function:
The intake valve allows the precise entry of the air-fuel mixture into the combustion chamber. Properly sealing valves are critical for maintaining compression, fuel efficiency, and smooth idle. A high-quality OE Match valve ensures exact timing, optimal airflow, and factory-level performance across the rev range.
Why & When Replacement Matters
Why:
Continuous exposure to heat, carbon build up, and mechanical stress can cause valve face wear, pitting, or bending, leading to loss of compression, rough running, and reduced power.
When:
- During engine rebuilds or top-end overhauls
- When compression loss or poor idle is detected
- If valves show visible wear, burn marks, or stem play
- As part of routine maintenance for high-mileage or performance engines
Replacing with an OE Match intake valve restores engine efficiency, reliability, and preserves the authentic performance character of your classic Porsche.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110540700
90110540700
The product you are viewing cross references to these numbers
€35.10
Now €31.59
In stock
Vehicle Group
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 914 (1970-1976)
Information
Cylinder head exhaust valve.
The exhaust valve opens and closes in time with the camshaft to release burnt gases after combustion. A correctly sealing valve helps maintain compression, stable idle, clean running, and consistent performance.
Sold each, 6 required per vehicle.
Fits:
Porsche 911 S/TU/T/E 1965 - 1969
Porsche 914-6 1970 - 1976
Diagram ref no 10
This valve forms a gas-tight seal against the valve seat to contain combustion pressure, then opens to allow exhaust flow out of the cylinder. Because exhaust valves operate under high heat, correct material quality and precise machining are critical for longevity and reliable sealing
A worn, pitted, or burnt exhaust valve can cause compression loss, misfires, poor performance, and potentially lead to costly cylinder head damage if ignored. Replacing valves during a rebuild helps restore correct sealing and reliable operation under heat load.
When to replace:
• Low compression / leak-down points to valve sealing issues
• Burnt valve symptoms (misfire, rough idle, power loss)
• Visible pitting, tuliping, or seat damage during teardown
• Excessive valve stem wear found during head inspection
• During cylinder head overhaul or full engine rebuild
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110540850
The product you are viewing cross references to these numbers
The exhaust valve opens and closes in time with the camshaft to release burnt gases after combustion. A correctly sealing valve helps maintain compression, stable idle, clean running, and consistent performance.
Sold each, 6 required per vehicle.
Fits:
Porsche 911 S/TU/T/E 1965 - 1969
Porsche 914-6 1970 - 1976
Diagram ref no 10
This valve forms a gas-tight seal against the valve seat to contain combustion pressure, then opens to allow exhaust flow out of the cylinder. Because exhaust valves operate under high heat, correct material quality and precise machining are critical for longevity and reliable sealing
A worn, pitted, or burnt exhaust valve can cause compression loss, misfires, poor performance, and potentially lead to costly cylinder head damage if ignored. Replacing valves during a rebuild helps restore correct sealing and reliable operation under heat load.
When to replace:
• Low compression / leak-down points to valve sealing issues
• Burnt valve symptoms (misfire, rough idle, power loss)
• Visible pitting, tuliping, or seat damage during teardown
• Excessive valve stem wear found during head inspection
• During cylinder head overhaul or full engine rebuild
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110540850
90110540850
The product you are viewing cross references to these numbers
€38.61
Now €34.75
In stock
Vehicle Group
- Porsche 914 (1970-1976)
Information
Exhaust valve (36 mm).
Fits:
Porsche 912 Coupè, 2.0
Porsche 912 E, 2.0
Porsche 914 2.0L
Valve Head Ø: 36 mm
Valve Stem Ø: 9 mm
Valve Shaft Length: 117 mm
Valve Seat Angle: 45 °
Click 'Zoom in' for large parts diagram.
Diagram Ref No 17.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
039109611L
The product you are viewing cross references to these numbers
Fits:
Porsche 912 Coupè, 2.0
Porsche 912 E, 2.0
Porsche 914 2.0L
Valve Head Ø: 36 mm
Valve Stem Ø: 9 mm
Valve Shaft Length: 117 mm
Valve Seat Angle: 45 °
Click 'Zoom in' for large parts diagram.
Diagram Ref No 17.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
039109611L
039109611L
039109611E
039109611J
The product you are viewing cross references to these numbers
Price: €158.22
Orderable