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- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
The OE Match Engine Cylinder Head Inlet Valve is a high-quality replacement valvetrain component designed to control the intake of the air-fuel mixture into the engine's combustion chamber. Manufactured to OE specifications for fit, precision and durability, this inlet valve plays a vital role in engine breathing, combustion efficiency and overall performance.
Fits:
- Porsche 911 1968-1973 2.2L / 2.4L / 2.7L RS LWB (F)
- Porsche 911 1974-1977 2.7L / 1976-77 3.0 Carrera
Diagram Ref No 9
Constructed from premium-grade materials and precision-engineered to withstand continuous operation, the inlet valve works in conjunction with the camshaft, valve spring, valve guide and cylinder head assembly to ensure accurate timing and efficient airflow. Proper valve operation is essential for maintaining engine power, fuel efficiency and smooth running characteristics.
What This Product Does:
- Controls the flow of air and fuel into the combustion chamber.
- Opens and closes in precise timing with the engine cycle.
- Maintains an effective seal when closed.
- Supports efficient combustion and engine performance.
- Helps maximise engine power output.
- Contributes to fuel efficiency and emissions control.
- Forms an essential part of the engine valvetrain system.
Symptoms Of Wear Or Failure:
- Loss of engine power and acceleration.
- Rough idle or uneven engine running.
- Engine misfires.Reduced fuel efficiency.
- Low compression in the affected cylinder.
- Difficulty starting the engine.
- Hesitation during acceleration.
- Engine management warning lights or fault codes.
- Ticking or tapping noises from the cylinder head.
- Failed compression or leak-down test results.
Why Replacement Matters:
- Inlet valves operate continuously under demanding conditions and are subjected to repeated opening and closing cycles, high temperatures and constant airflow. Over time, valves can become worn, bent, burnt, carbon-contaminated or develop sealing issues that affect engine performance and combustion efficiency.
- A damaged inlet valve can reduce airflow into the combustion chamber, leading to poor combustion, reduced power, increased fuel consumption and compression loss. If left unresolved, valve failure can contribute to further damage within the cylinder head, valve seat and other internal engine components, potentially resulting in costly repairs.
- 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 protection for your Porsche engine.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
91110541120
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
Valve Spring
Sold each
The Porsche Valve Spring is a critical component
of the valve train system fitted to numerous Porsche 911 and Porsche 964 models
from 1965 to 1994. Designed to maintain precise valve operation throughout the
engine's RPM range, the valve spring ensures that intake and exhaust valves
close correctly after being opened by the camshaft.
Fits:
- 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
Diagram Ref No 13
In Porsche's legendary air-cooled flat-six engines, accurate valve control is essential for maintaining combustion efficiency, engine performance, reliability, and long-term durability. The valve spring works continuously under extreme mechanical stress, cycling thousands of times per minute to keep the valve train operating correctly.
Whether you're rebuilding a classic Porsche engine, restoring a 911, or carrying out a cylinder head overhaul, replacing worn valve springs helps maintain factory performance and reduces the risk of costly engine damage.
What Does the Valve Spring Do?
The valve spring is responsible for returning the intake and exhaust valves to their closed position after each opening cycle generated by the camshaft.
Its key functions include:
- Maintaining correct valve timing operation
- Ensuring valves close fully and consistently
- Keeping the valve train under proper tension
- Preventing valve float at higher engine speeds
- Supporting engine compression and combustion efficiency
- Protecting the valve train from instability and excessive wear
Without adequate spring tension, valves may not close correctly, leading to poor performance and potential engine damage.
Why Does the Valve Spring Fail?
Valve springs are constantly subjected to compression, heat, vibration, and high engine speeds. Over time, these factors can lead to material fatigue and a gradual loss of spring tension.
Common causes of valve spring failure include:
- Metal fatigue from repeated cycling
- High mileage wear
- Prolonged exposure to engine heat
- Over-revving the engine
- Corrosion or contamination
- Performance modifications increasing valve train loads
- Age-related weakening of spring material
- Improper engine assembly or valve train geometry
As spring pressure decreases, valve control becomes less precise, particularly at higher RPM.
Common Symptoms of Worn Valve Springs
A weakened or damaged valve spring may cause:
- Loss of engine performance
- Valve float at higher RPM
- Rough idle
- Engine misfires
- Increased valve train noise
- Reduced power output Inconsistent compression readings
- Premature wear of valves, guides, and camshaft components
In severe cases, a broken valve spring can result in valve-to-piston contact and major engine damage.
When Should You Replace Valve Springs?
Valve springs should be inspected whenever the cylinder heads are removed and replaced if any signs of fatigue or wear are detected.
Replacement is strongly recommended:
- During complete engine rebuilds
- During cylinder head refurbishment
- On high-mileage engines
- When installing performance camshafts
- If valve float is present
- When spring tension falls below specification
- During preventative maintenance on restoration projects
- Whenever a spring shows signs of corrosion or damage
Many experienced Porsche engine builders replace all valve springs during rebuilds to ensure consistent valve train performance and long-term reliability.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90110590151
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)
This is the standard valve guide used in early air-cooled Porsche 911/930 cylinder heads. It’s a plain (non-hydraulic) guide that locates the valve stem in the head; when worn it causes oil burning, loss of compression and poor valve seating — so they’re commonly replaced whenever heads are rebuilt
- Fits:
- 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)
Diagram Ref No 2 and 2A.
What the part is (technical data / dimensions)
Application:
Porsche 911 / 930 from about 1965–1989 (varies slightly by model and year; early cars both intake & exhaust, later years sometimes exhaust only).
Standard size (typical OE): ID ≈ 9.00 mm, OD ≈ 13.06 mm, length ≈ 51.2 mm.
Why these guides should be replaced
- Valve guides are a wearing item. Replace them when any of the following occur or when you rebuild the engine head.
- Excessive valve stem play — worn guide ID internal diameter lets the valve rock and misalign with the seat , poor sealing, reduced compression and power.
- Oil consumption / smoking — worn guides allow oil to wick down the stem into the combustion chamber, causing blue/grey smoke and fouled plugs.
- Hard starting, rough idle, misfire — poor sealing / valve timing irregularities from misaligned valves.
- Valve wobble that leads to premature valve stem wear or valve seat damage — once stems or seats are damaged you need deeper surgery.
- If a guide is cracked, broken, or has excessive ovality — must be replaced.
- Whenever you remove and refinish seats / replace springs / do a full head rebuild — replacing guides at that time is cheap insurance and ensures correct alignment.
Inner diameter 9,00 mm
Outer diameter 13,06 mm
Total Length 51,20 mm
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
93010432100
The product you are viewing cross references to these numbers
- 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) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
Manufactured to OEM specifications, this valve matches the factory dimensions, seat angle, and stem diameter for perfect sealing and valve timing accuracy. Built from high-grade heat-resistant steel, it delivers excellent thermal stability and wear resistance, ideal for the demanding environment of Porsche’s high-revving flat-six engines.
Fits:
Porsche 964 C2/C4 3.6L 1990-94
Porsche 911 3.3L Turbo 1978-89
911 (964), 3.3 Turbo M 30.69
911 (964), 3.3 Turbo S M 30.69S
911 (964), 3.6 Carrera M 64.01/M 64.02
911 (964), 3.6 Carrera M 64.01/M 64.02
911 (964), 3.6 Carrera 4 M 64.01
911 (964), 3.6 Carrera RS M 64.03
911 (964), 3.6 Turbo M 64.50
911 Cabriolet (964), 3.6 Carrera M 64.01/M 64.02
911 Cabriolet (964), 3.6 Carrera M 64.01/M 64.02
911 Cabriolet (964), 3.6 Carrera 4 M 64.01
911 Speedster (964), 3.6 CarreraM 64.01/M 64.02
911 Speedster (964), 3.6 CarreraM 64.01/M 64.02
911 Targa (964), 3.6 Carrera M 64.01/M 64.02
911 Targa (964), 3.6 Carrera M 64.01/M 64.02
911 Targa (964), 3.6 Carrera 4 M 64.01
Valve head diameter 9,00 mm
Valve stem diameter 9,00 mm
Valve shaft length 110,10 mm
Valve seat angle 45 °
Diagram Ref No 11.
Function:
The inlet valve controls the flow of air-fuel mixture into the combustion chamber. Proper sealing and timing are essential for maintaining compression, combustion efficiency, and overall power output. A high-quality OE Match valve ensures consistent intake airflow, reliable operation, and long engine life.
Why & When Replacement Matters
Why: Over time, inlet valves experience wear from heat, carbon build up, and mechanical stress, which can lead to reduced compression, power loss, and rough engine operation.
When: During engine rebuilds or cylinder head servicing If there are signs of valve leakage, pitting, or stem wear. When experiencing loss of power, misfires, or compression imbalance. As preventive maintenance on high-mileage engines or performance builds.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
93010540901
The product you are viewing cross references to these numbers