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- 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
M8 Exhaust Nut - M8
Sold each and used throughout
The Porsche M8 Exhaust Nut is a high-quality
replacement fastener used in various positions across Porsche exhaust systems.
Designed to secure exhaust components such as manifolds, heat exchangers,
silencers, brackets and connecting flanges, this nut helps maintain correct
clamping force and reliable exhaust sealing.
Fits:
- 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
Exhaust nuts operate in extremely harsh conditions, exposed to heat cycles, vibration, moisture, road salt and corrosion. Over time, original nuts can seize, round off, strip or weaken, making removal difficult and reducing their ability to hold exhaust components securely.
Replacing worn exhaust hardware during servicing or restoration helps ensure a secure, leak-free and professional exhaust installation.
What Does an Exhaust Nut Do?
An exhaust nut fastens exhaust components to studs or bolts, holding joints tightly together and helping maintain gasket compression.
A correctly fitted exhaust nut helps provide:
- Secure exhaust component mounting
- Proper gasket sealing
- Reduced risk of exhaust leaks
- Correct exhaust alignment
- Improved resistance to vibration
- Long-term exhaust system reliability
Symptoms of Wear or Failure
Common signs that an exhaust nut may need replacement
include:
- Rust or heavy corrosion
- Rounded or damaged edges
- Stripped threads
- Seized nut during removal
- Loose exhaust joints
- Exhaust blowing noises
- Rattling or vibration from the exhaust
- Soot marks around exhaust flanges
- Inability to tighten to the correct torque
Why Replacement Matters
Replacing worn or corroded exhaust nuts helps prevent exhaust leaks, loose components and future repair difficulties.
Benefits include:
- Restores secure exhaust fastening
- Helps prevent exhaust leaks
- Improves gasket sealing
- Reduces vibration and rattles
- Makes future maintenance easier
- Supports reliable exhaust repairs
- Protects surrounding exhaust components
- Improves restoration quality
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90091009701
The product you are viewing cross references to these numbers
- 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 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Fits:
Porsche 911 1969 - 1977
Porsche 914-6 1970 - 1976
Porsche 924 1976 - 1979
Diagram ref no 6
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90007514803
The product you are viewing cross references to these numbers
- 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 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Heat Exchanger Hexagon Nut – M10
Sold each
Ensure a secure and reliable exhaust installation with this Heat Exchanger Hexagon Nut. Manufactured to original equipment specifications, this high-quality
replacement hexagon nut is used to securely fasten the heat exchanger to the
engine's exhaust studs, ensuring a tight, leak-free connection.
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
- Porsche 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Diagram ref no 7
Heat exchanger mounting hardware is continually exposed to extreme exhaust temperatures, moisture, road salt and vibration. Over time, the original nuts can corrode, seize or lose their clamping force, making removal difficult and increasing the risk of exhaust leaks. Replacing worn or damaged hardware whenever the exhaust system is removed is considered best practice for both servicing and restoration work.
Manufactured from durable, corrosion-resistant materials, this OE Match hexagon nut provides dependable clamping force and long service life, making it ideal for routine maintenance, exhaust repairs and concours restorations.
What Does the Heat Exchanger Hexagon Nut Do?
The hexagon nut secures the heat exchanger to the cylinder head via the exhaust studs.
Its primary functions include:
- Securing the heat exchanger firmly in position.
- Maintaining correct gasket compression.
- Preventing exhaust gas leaks.
- Resisting loosening caused by vibration and heat cycling.
- Supporting proper exhaust alignment.
- Helping maintain engine performance and efficiency.
Correctly tightened exhaust hardware is essential for a safe and reliable exhaust system.
Why Should the Heat Exchanger Nut Be Replaced?
Exhaust mounting hardware operates under extremely demanding conditions.
Common reasons for replacement include:
- Corrosion caused by moisture and road salt.
- Heat cycling leading to material fatigue.
- Seized or rounded nuts during removal.
- Damaged threads.
- Reduced clamping force.
- Exhaust system restoration.
- Heat exchanger replacement.
Replacing the hardware during exhaust work helps avoid future maintenance issues and ensures a secure installation.
Symptoms of Worn or Damaged Exhaust Hardware
Typical signs include:
- Rusted or heavily corroded nuts.
- Seized fixings.
- Exhaust leaks.
- Loose heat exchanger.
- Rattling exhaust components.
- Broken or damaged fasteners.
- Difficulty removing existing hardware.
Renewing the mounting hardware helps restore the integrity of the complete exhaust system.
When Should the Heat Exchanger Hexagon Nut Be Replaced?
Replacement is recommended whenever:
- Heat exchangers are removed.
- Exhaust gaskets are replaced.
- Exhaust manifold repairs are carried out.
- Engine rebuilds are performed.
- Restoring a classic Porsche.
- Existing nuts show signs of corrosion or damage.
Installing new hardware during reassembly helps ensure reliable sealing and long-term durability.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
99908400202
The product you are viewing cross references to these numbers
- 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 924 2.0L 1976-79
- Porsche 914 (1970-1976)
Fits:
Porsche 911 1969 - 1977
Porsche 914-6 1970 - 1976
Porsche 924 1976 - 1979
Diagram ref no 6
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
90007514803
The product you are viewing cross references to these numbers