Athena 330023R BMW M52 / M54 Cooper Ring Performance Head Gasket

The Athena 330023R Head Gasket is a high-performance cylinder-head gasket developed for selected BMW straight-six M52 and M54 24-valve engines.

Designed for engines operating beyond standard factory performance levels, this Athena gasket combines a reinforced gasket construction with separate stainless-steel cylinder sealing rings, helping maintain an effective combustion seal when subjected to increased cylinder pressure and temperature.

With an 87.6mm gasket bore and 1.50mm thickness, the 330023R is an excellent solution for performance BMW engine rebuilds, modified road cars, track cars and forced-induction projects where dependable cylinder-head sealing is essential.

High-Performance Cooper Ring Technology

Athena’s Cooper Ring system has been developed for high-output engine applications where conventional head gasket arrangements may be pushed beyond their intended operating conditions.

The gasket uses separate stainless-steel sealing rings around the cylinder bores, concentrating sealing force around the combustion chambers.

This makes the Athena 330023R particularly attractive for:

• Turbocharged BMW engine builds
• Supercharged BMW engines
• High-compression naturally aspirated builds
• Track and motorsport vehicles
• Performance road cars
• Rebuilt or uprated M52/M54 engines
• High-cylinder-pressure applications

Athena states that its Cooper Ring design provides enhanced cylinder sealing and is designed for demanding high-performance applications, including boosted engines.

87.6mm Bore for Performance Engine Builds

The 330023R features an 87.6mm gasket bore, providing additional clearance compared with standard-bore applications and making it especially useful where the engine specification requires this particular gasket diameter.

Athena recommends that the gasket bore should generally be approximately 0.5–1.0mm larger than the engine cylinder bore, although the final gasket specification must always be confirmed by the engine builder or machinist responsible for the engine.

1.50mm Gasket Thickness

The supplied gasket has a nominal thickness of 1.50mm.

Head gasket thickness affects several important engine parameters, including:

• Piston-to-head clearance
• Quench / squish clearance
• Compression ratio
• Cylinder-head-to-block spacing
• Cam timing geometry on some engine combinations

For this reason, performance engine builders should always confirm that 1.50mm is appropriate for the exact engine configuration before installation.

Designed for BMW M52 and M54 Engines

Athena catalogue information for 330023R identifies applications including BMW engines such as:

M52B25
M52B28
M54B25
M54B30
M54 256 S3 / S5
M54 306 S3

Vehicle applications commonly associated with these engines include selected BMW 320, 325 and 330 24-valve models, particularly E46-generation applications.

Because BMW engine specifications can differ according to year, chassis, market and engine code, customers should verify compatibility using the engine code rather than relying on vehicle model alone.

Key Features

• Genuine Athena performance head gasket
• Athena part number 330023R
• Designed for selected BMW M52 and M54 engines
• 87.6mm gasket bore
• 1.50mm gasket thickness
• Cooper Ring / Cut Ring sealing technology
• Separate stainless-steel cylinder sealing rings
• Reinforced performance gasket construction
• Enhanced combustion-chamber sealing
• Suitable for high-cylinder-pressure applications
• Ideal for turbocharged and supercharged builds
• Suitable for performance road and motorsport engines
• Compatible with selected BMW 320 / 325 / 330 applications
• Suitable for selected M52B25, M52B28, M54B25 and M54B30 engines
• Premium alternative for modified BMW straight-six engines

Technical Specifications

Why Choose Athena 330023R?

A performance engine produces significantly higher cylinder pressures and temperatures than a standard road engine. Maintaining an effective seal between the cylinder block and cylinder head therefore becomes increasingly important as power increases.

The Athena 330023R BMW performance head gasket is designed to address these demands through its reinforced construction and dedicated stainless-steel cylinder sealing rings.

For BMW enthusiasts building an uprated M52 or M54 engine, this makes the Athena gasket a strong choice for applications including:

Turbo conversions
Supercharger conversions
Forged engine builds
High-compression builds
Track-day vehicles
Competition cars
High-power road cars

Important Installation Information

Professional installation is strongly recommended.

Before ordering or installation, confirm:

• Exact BMW engine code
• Cylinder bore
• Finished block bore diameter
• Cylinder-head condition
• Block deck condition
• Required gasket thickness
• Compression-ratio requirements
• Piston-to-head clearance
• Engine builder specifications

For Cut Ring versions with separate sealing rings, installation orientation must also be followed correctly. Specialist product documentation for this Athena gasket specifies that the ring grooves are fitted towards the cylinder head.

Always follow the latest Athena installation instructions and your engine builder’s recommendations.

Compatibility Summary

Commonly associated applications include selected:

BMW 320i 24V
BMW 325i 24V
BMW 330i 24V
BMW 325Ci
BMW 330Ci

with compatible M52/M54 engine configurations.

Compatible Engine Families

• BMW M52
• BMW M54

Referenced Engine Codes

• M52B25
• M52B28
• M54B25
• M54B30
• M54 256 S3
• M54 256 S5
• M54 306 S3

Important: Compatibility should be confirmed from the engine code and required gasket dimensions, not simply the BMW badge/model. Athena catalogue and aftermarket fitment databases show some differences in the model/year ranges assigned to this part.

FAQ

Is the Athena 330023R a standard replacement BMW head gasket?

The 330023R is primarily a performance-oriented Cooper Ring / Cut Ring head gasket, designed for demanding engine applications rather than simply being marketed as a basic OE-style replacement.

What is the bore of the Athena 330023R?

The gasket has an 87.6mm bore.

What is the thickness?

The Athena 330023R has a nominal 1.50mm thickness.

Which BMW engines can use Athena 330023R?

Athena catalogue information identifies applications including selected M52B25, M52B28, M54B25 and M54B30 engines. Exact compatibility should always be checked against the engine code, bore and required gasket dimensions.

Is Athena 330023R suitable for turbocharged BMW engines?

The Cooper Ring design is specifically intended for demanding, high-cylinder-pressure applications and is commonly selected for turbocharged, supercharged and high-performance BMW builds. The complete engine specification must still be approved by the engine builder.

Does it fit a BMW 330i?

It is associated with selected BMW 330i/330Ci 24V applications, particularly those using compatible M54B30 engine specifications. Always verify your engine code before ordering.

Does it fit a BMW 325i?

It is associated with selected 325i/325Ci applications using compatible M52/M54 engine configurations. Confirm engine code and gasket dimensions before purchase.