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- 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
Exhaust Valve - Varioram
Engines
Sold each - 6 required per car
Maintain the performance, efficiency and reliability of your
Porsche 993 Varioram engine with this OE Match Exhaust Valve.
Designed specifically for Porsche 993 Varioram engines including M64.21,
M64.22, M64.23 and M64.24 engine variants, this exhaust valve plays a critical
role in the combustion process by allowing spent exhaust gases to exit the
combustion chamber efficiently.
Fits:
- Porsche 993 (911) C2 1996-97
- Porsche 993 (911) C4 1996-97
- Porsche 993 (911) RS 1996-97
- Porsche 993 (911) C2S 1996-97
- Porsche 993 (911) C4S 1996-97
Diagram Ref No 10
Operating under extreme temperatures and pressures, exhaust valves are among the hardest-working components within the engine. During every combustion cycle, they must withstand intense heat while maintaining an effective seal against the valve seat to preserve compression, power output and engine efficiency.
Manufactured to OE Match specifications, this exhaust valve is ideal for engine rebuilds, cylinder head refurbishment, top-end overhauls and preventative maintenance projects.
Technical Specification
Valve
Head Diameter: 43.50 mm
Valve
Stem Diameter: 8.00 mm
Valve
Shaft Length: 109.00 mm
Valve
Seat Angle: 45°
Suitable
for Porsche 993 Varioram engines:
M64.21
M64.22
M64.23
M64.24
What Does the Exhaust Valve Do?
The exhaust valve is responsible for controlling the exit of combustion gases from the cylinder.
Its primary functions include:
- Releasing burnt exhaust gases
- Maintaining combustion chamber sealing
- Supporting efficient engine breathing
- Preserving compression
- Assisting engine performance
- Supporting fuel efficiency
- Maintaining smooth engine operation
Correct exhaust valve operation is essential for maintaining the power and responsiveness expected from the Porsche 993 Varioram engine.
Why Do Exhaust Valves Fail?
Exhaust valves are exposed to some of the harshest operating conditions within the engine.
Common causes of failure include:
- Extreme heat exposure
- Valve seat wear
- Carbon build-up
- High mileage wear
- Detonation damage
- Valve guide wear
- Overheating
Over time, valves can become worn, burnt, pitted or damaged, reducing their ability to seal effectively.
Symptoms of a Worn or Damaged Exhaust Valve
Common warning signs include:
- Reduced engine compression
- Loss of power
- Rough idle
- Increased exhaust emissions
- Misfires
- Excessive oil consumption
- Poor throttle response
- Unusual engine noise
In severe cases, a burnt valve can significantly affect engine performance and drivability.
When Should Exhaust Valves Be Replaced?
Replacement is recommended when:
- Carrying out a cylinder head rebuild
- Performing a top-end engine overhaul
- Valve seat damage is present
- Compression loss is identified
- Burnt valves are discovered
- Valve stem wear exceeds specifications
- Rebuilding a high-mileage engine
- Completing a full engine restoration
Professional engine builders routinely inspect and measure all valves during rebuild work.
Why Replacement Matters
A worn exhaust valve can compromise engine performance, reliability and efficiency.
Benefits of replacement include:
- Restored compression
- Improved power delivery
- Better engine efficiency
- Smoother operation
- Improved combustion quality
- Reduced emissions
- Increased engine reliability
- Long-term engine protection
Replacing worn valves during a rebuild helps ensure the longevity of expensive engine components.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99310541906
The product you are viewing cross references to these numbers
- Porsche 924 2.0L 1976-79
- Porsche 924 2.0L 1980-85
- Porsche 924 Turbo 2.0L 1979-81
- Porsche 924 Turbo 2.0L 1982-84
Fits:
Porsche 924 (1976 - 1985)
Porsche 924 Turbo (1979 - 1982)
Click 'Zoom in' for large parts diagram.
Diagram ref no 18
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PCG10945300
The product you are viewing cross references to these numbers
- Porsche 924 2.0L 1976-79
- Porsche 924 2.0L 1980-85
- Porsche 924 Turbo 2.0L 1979-81
- Porsche 924 Turbo 2.0L 1982-84
- Porsche 924 Carrera GT 2.0L 1981
- Porsche 924 Carrera GTS 2.0L 1982
Fits:
Porsche 924 (1976 to 1985)
Click 'Zoom in' for large parts diagram.
Diagram ref no 22
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PCG109623
The product you are viewing cross references to these numbers
- Porsche 924 2.0L 1976-79
- Porsche 924 2.0L 1980-85
- Porsche 924 Turbo 2.0L 1979-81
- Porsche 924 Turbo 2.0L 1982-84
- Porsche 924 Carrera GT 2.0L 1981
- Porsche 924 Carrera GTS 2.0L 1982
Sold each - 8 required per car
Fits:
Porsche 924 - 1976 to 1985
Porsche 924 turbo - 1979 to 1984
Porsche 924 Carrera GT - 1981 to 1982
Diagram ref no 27
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
046109675A
The product you are viewing cross references to these numbers