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- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
The OE Match exhaust valve is a precision engine component designed for Porsche 911 (993) Carrera models equipped with early 3.6L engines. It is installed in the cylinder head and forms part of the valve train responsible for controlling the flow of exhaust gases from the combustion chamber to the exhaust system.
Sold individually, 6 required per vehicle
Fits:
Porsche 993 C2 / C4 3.6L 1993 - 1995
* with Engine codes: M64.05 / M64.06 / M64.07 / M64.08
Diagram Ref No 10
The OE Match version of part number 99310541901 is designed for pre-Varioram Porsche 993 engines used in early Carrera models. It is engineered with the correct stem diameter, valve head size and material specification to withstand the extreme temperatures and stresses experienced in high-performance air-cooled engines.
The exhaust valve regulates the release of burnt gases from the combustion chamber. When opened at the correct time by the camshaft, it allows exhaust gases to exit the cylinder and enter the exhaust system, preparing the chamber for the next intake cycle.
Maintaining properly functioning valves is essential for efficient combustion, engine power and reliable operation.
Exhaust valves operate under extremely high temperatures and continuous mechanical stress. Over time they may wear, warp or suffer from carbon buildup, which can lead to compression loss, poor engine performance or valve train noise. Replacing worn valves during engine service or rebuild ensures proper combustion sealing and reliable engine operation.
Consider replacing the exhaust valve if you notice:
• Loss of compression or engine power
• Excessive valve train noise
• Burnt or worn valve surfaces
• During cylinder head rebuild or engine overhaul
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310541901
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 1965-1968 2.0L / 912 SWB (F)
- Porsche 914 (1970-1976)
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
The product you are viewing cross references to these numbers
- Porsche 911 1965-1968 2.0L / 912 SWB (F)
- Porsche 914 (1970-1976)
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