Connection Rod Nut. Porsche 912 / 356  ❭  50203114

Connection rod bolt.
12 per engine. Price is for each.



Fits:
Porsche 993 1994-98
Porsche 996 Turbo / GT2 1998-05
Porsche 997 Turbo / GT2 2005-08

Click 'Zoom in' for large parts diagram.
Diagram Ref No 10.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99610317670

The product you are viewing cross references to these numbers

Con Rod Nut 
Sold each - 12 required per car

The OE Match Con Rod Nut is a critical internal engine fastener used to secure the connecting rod cap to the connecting rod assembly. Suitable for various Porsche 911, 964, 993, 996 Turbo and 997 Turbo engines, this precision-engineered component plays a vital role in maintaining the structural integrity of the engine's rotating assembly.

Fits:

• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50
• 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
• 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
• Porsche 993 (911) TURBO 1994-96
• Porsche 993 (911) GT2 1994-97
• Porsche 993 (911) TURBO S 1994-97
• Porsche 996 TURBO 2000-05
• Porsche 996 GT2 2001-05
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MK1 GT2 2007-09

Diagram Ref No 11

The connecting rod assembly is subjected to enormous forces during engine operation, particularly at high RPM. The con rod nuts must maintain precise clamping force to ensure the connecting rod cap remains securely attached under extreme combustion and inertial loads. Even the slightest loss of clamping force can result in catastrophic engine failure.

For this reason, con rod nuts are considered a critical engine rebuild component and should always be replaced during engine overhauls, connecting rod servicing or performance engine builds.

What Does a Con Rod Nut Do?

The con rod nut secures the connecting rod cap to the connecting rod body, clamping around the crankshaft journal bearing.

Its functions include:

• Maintaining connecting rod cap security
• Preserving bearing crush and alignment
• Supporting crankshaft rotation
• Withstanding high engine loads
• Maintaining precise clamping force
• Supporting engine reliability
• Protecting internal engine components

The connecting rod assembly relies entirely on the integrity of its fastening hardware to survive the extreme loads generated during operation.

Why Do Con Rod Nuts Fail?

Con rod nuts are subjected to repeated tensile loads, heat cycles and vibration throughout their service life.

Common causes of failure include:

• Metal fatigue
• Repeated engine stress cycles
• Overstretching during previous installation
• Improper torque procedures
• High mileage wear
• Performance engine operation
• Corrosion during storage
• Reuse during multiple rebuilds

Many con rod nuts are designed as single-use fasteners and can lose their ability to maintain proper clamping force if reused.

When Should Con Rod Nuts Be Replaced?

Replacement is strongly recommended whenever the connecting rods are disassembled.

Typical situations include:

• Engine rebuilds
• Crankshaft replacement
• Connecting rod servicing
• Bearing replacement
• Performance engine upgrades
• Motorsport engine preparation
• Full engine restoration projects
• Preventative rebuild maintenance

As con rod nuts are relatively inexpensive compared to the cost of engine repairs, replacing them during rebuild work is considered essential best practice.

Why Replacement Matters

The con rod nut is one of the most critical fasteners within the entire engine.

Benefits of replacement include:

• Maintains correct clamping force
• Supports bearing integrity
• Reduces risk of engine failure
• Improves engine reliability
• Protects expensive internal components
• Essential for professional engine builds
• Supports high-performance applications
• Provides peace of mind during rebuilds

For air-cooled and turbocharged Porsche engines, correct connecting rod hardware is fundamental to long-term durability and performance.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99310317403

The product you are viewing cross references to these numbers

Connection Rod Bolt 3/8 x 24 WMC Bolt 1.600UHL H6 or WMC6 Head Marking.
Price is Each


Diagram Ref No 10.