Cylinder head bolt long, Set of 12. Porsche Boxster / Cayman / 996 / 997  ❭  99610418059

Cylinder head bolt long. M10 x 230
Cylinder head bolts are high-strength engine fasteners that clamp the cylinder head, head gasket and engine block together. The OE Match set contains 12 long bolts, which is the correct quantity required for one cylinder head in Porsche M96 and M97 engines 
SET OF 12  is required per cylinder head (two sets per engine)

Fits:
Porsche 986 Boxster 2.7L / S 3.4L 2003 - 2004
Porsche 987.1 Boxster 2005 - 2008
Porsche 987C.1 Cayman 2005 - 2008
Porsche 996 C2 / C4 / C4S 2002 - 2005
Porsche 997.1 Carrera 2005 - 2008

Diagram ref no 20.

These bolts are engineered to withstand extreme engine conditions such as high combustion pressure, temperature fluctuations and constant mechanical stress. OE Match bolts are produced to match the original Porsche specifications to ensure correct torque application and reliable engine assembly.

The cylinder head bolts apply precise clamping force between the cylinder head and engine block. This pressure compresses the head gasket, creating a tight seal that prevents coolant or oil leakage while maintaining proper compression inside the combustion chambers.

Replacing the bolts during engine service helps maintain the integrity of the engine assembly and ensures reliable performance.

Function
•  Engine Fastening: Secures the cylinder head to the engine block
•  Gasket Compression: Maintains the seal of the head gasket
•  Combustion Stability: Preserves compression inside the cylinders
•  Structural Strength: Designed to withstand heat, pressure and engine vibration

Cylinder head bolts are subjected to extreme pressure and thermal expansion during engine operation. Many modern bolts are torque-to-yield fasteners, meaning they stretch slightly during installation and should be replaced once removed. Using new bolts during engine repairs ensures correct clamping force and prevents potential head gasket failure, oil leaks or overheating issues.

Consider replacing cylinder head bolts when:
•  Replacing the cylinder head gasket
•  Performing a top-end engine rebuild
•  Removing or reinstalling the cylinder head
•  High-mileage engine maintenance

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