King Engine Bearings MB7776GPC GPC Main Bearing Set BMW N52 N53 N55 B30A STD

Vehicle Fitment

• BMW N52 B30A (naturally aspirated 3.0L inline-6) - E82/E88 128i, E90/E91/E92/E93 325i/328i/330i, E60/E61 525i/528i/530i, E70 X5 xDrive30i, E83 X3, and other N52-powered applications
• BMW N53 B30A (naturally aspirated 3.0L direct injection inline-6) - European-market 3-series, 5-series, and X3/X5 variants with N53
• BMW N55 B30A (single-turbocharged 3.0L inline-6) - E82/E88 135i, E84 X1 xDrive35i, E70 X5 xDrive35i, E71 X6 xDrive35i, E90/E92/E93 335i, E60 535i, and other N55-powered applications

Fitment Notes

• The MB7776GPC fits BMW inline-6 engines sharing the N52/N53/N55 main bearing journal specification - housing bore 70.02/70.00mm, crankshaft journal 64.98/64.96mm. Verify your specific engine code matches N52 B30A, N53 B30A, or N55 B30A before ordering.
• Available sizes: Standard (STD) - this listing, Standard with Extra Clearance (STDX), +0.026mm, and +0.25mm. Measure crankshaft main journals and consult your engine builder before selecting a size.
• Sold as a complete set of 7 pairs (14 shells) - covers all 7 main bearing positions in the BMW inline-6 crankshaft.
• GPC is King's silver-based tri-metal race material - a fundamentally different and higher load-capacity material than the XP (pMaxBlack copper-lead) series. The GPC's silver overlay is rated to 17,000 PSI versus approximately 11,000 PSI for XP-series bearings. This makes it specifically appropriate for forced induction, high-boost, and extreme-load BMW builds where XP-series capacity may be insufficient.
• The GPC polymer coating is factory-applied with no added wall thickness - maintaining the original dimensional specification at the stated nominal size.

Features

• GPC (Polymer-SilveRace) silver-based tri-metal construction is King's highest load-capacity main bearing specification for extreme race applications - capable of withstanding up to 17,000 PSI compressive loading, significantly exceeding the ~11,000 PSI ceiling of conventional race materials and providing the necessary safety margin for high-boost N55 builds and other extreme-demand applications
• Silver overlay with solid lubricant particles distributed throughout the silver matrix provides outstanding anti-seizure and low-friction characteristics in addition to its extreme load capacity - the solid lubricant particles reduce friction during boundary lubrication conditions and provide emergency protection when the hydrodynamic oil film is momentarily insufficient
• Factory-applied polymer top coat over the silver overlay adds critical protection against oil starvation and metal-to-metal contact - essential for modified N55 and N52 applications where aggressive tuning, hard cornering, oil surge, or pressure transients can create conditions that damage even race-quality uncoated bearings
• The polymer coating maintains its protective function without altering the bearing's original wall thickness - all King polymer coatings are applied before final sorting and dimensioning, ensuring the stated nominal size is accurate without requiring clearance adjustment
• RadiaLock™ optimized crush height ensures consistent bearing-to-bore contact across all 7 main bearing positions, maximizing heat transfer out of the bearing shells and maintaining correct bearing retention under the high loads produced by boosted BMW inline-6 engines
• EccentriX™ optimized eccentricity ensures stable hydrodynamic oil wedge formation and consistent oil film distribution across the full crankshaft journal contact area at all RPM and load conditions
• Industry-leading wall thickness tolerance - outperforms standard industry shell-to-shell variation tolerances, ensuring the most consistent clearance relationship possible across all 14 shells in the complete 7-position set
• Designed for circle track, drag racing, off-shore, and all high-load, extended-duration racing applications utilizing steel crankshafts

Specifications

• Part Number: MB7776GPC
• Brand: King Engine Bearings
• Bearing Type: Main (Crankshaft) Bearing Set
• Series: GPC (Polymer-SilveRace - Silver-based tri-metal with factory polymer coating)
• Material Structure: Steel backing → Lead-bronze intermediate layer → Silver overlay with solid lubricant particles → Polymer top coat
• Maximum Load Capacity: Up to 17,000 PSI
• Polymer Coating Added Thickness: None (factory-dimensioned)
• Application Engines: BMW N52 B30A | N53 B30A | N55 B30A (3.0L inline-6)
• Housing Bore Dimension: 70.02 / 70.00 mm
• Crankshaft Journal Diameter: 64.98 / 64.96 mm
• Bearing Thickness: 2.508 mm
• Bearing Length: 19.8 mm
• Size: Standard (STD)
• Quantity per Set: 7 pairs (14 shells - complete inline-6 main bearing set)
• UPC: 611500626708
• Design Features: RadiaLock™ crush height | EccentriX™ eccentricity optimization | Industry-leading wall thickness tolerance

Included Components

• 14x GPC (Polymer-SilveRace) Main Bearing Shells (7 pairs - complete 7-main-journal inline-6 set in Standard size)

Product Description

The King Engine Bearings MB7776GPC is the GPC (Polymer-SilveRace) main bearing set for BMW N52 B30A, N53 B30A, and N55 B30A inline-6 engines. It includes 7 pairs (14 shells) covering all main bearing positions. Standard size - measure crankshaft journals and consult your engine builder before ordering. Housing bore 70.02/70.00mm, crankshaft journal 64.98/64.96mm.

The GPC is King's premium silver-based race bearing material, and it is the correct choice for forced induction and high-output BMW inline-6 applications where the XP-series (copper-lead, pMaxBlack) bearing's capacity may be insufficient. The silver overlay with solid lubricant particles is rated to 17,000 PSI - compared to approximately 11,000 PSI for the XP series - providing a decisive load capacity margin for turbocharged N55 builds producing significantly elevated cylinder pressures and main bearing loads. The factory-applied polymer coating over the silver overlay adds the critical second layer of protection against oil starvation and seizure, specifically addressing the failure modes that affect modified BMW engines under track use, sustained boost, and aggressive oil system demands.

Unlike the XPC series (which uses pMaxBlack tri-metal as the base), the GPC uses a silver-based intermediate layer over steel backing - a fundamentally different and higher-capacity metallurgical approach that is used in applications requiring protection beyond what conventional race tri-metal materials can provide. All dimensional processing including polymer coating is done at King's facility before final sorting, maintaining the original nominal size specification without added thickness. RadiaLock™ and EccentriX™ geometric features ensure consistent oil film distribution and bearing seating across all 7 main positions.