King MB5227XPSTDX XP Main Bearing Set for Mitsubishi 4G63/4G64 6-Bolt 1983-1997

Vehicle Fitment

• 1983 Mitsubishi Tredia (Base, L, LS, 1.8L I4, FWD)
• 1988-1989 Mitsubishi Mirage (Turbo, 2.0L 4G63 I4, FWD)
• 1990-1994 Mitsubishi Eclipse (Base, GS, 2.0L 4G64 I4, FWD)
• 1990-1994 Mitsubishi Eclipse (GST, 2.0L 4G63T I4 Turbo, FWD)
• 1990-1994 Mitsubishi Eclipse (GSX, 2.0L 4G63T I4 Turbo, AWD)
• 1991-1992 Mitsubishi Galant (Base, GS, GSR, GSX, LS, 2.0L 4G63 I4, FWD/AWD)
• 1991-1992 Mitsubishi Galant (VR-4, 2.0L 4G63T I4 Turbo, AWD)
• 1991-1992 Mitsubishi Mirage (GS, 2.0L 4G63 I4, FWD)
• 1990-1994 Eagle Talon (Base, DL, ES, ESi, 2.0L 4G64 I4, FWD)
• 1990-1997 Eagle Talon (TSi, 2.0L 4G63T I4 Turbo, FWD/AWD)
• 1993-1994 Eagle Talon (DL, ES, 2.0L 4G64 I4, FWD)
• 1995-1997 Eagle Talon (ESi, 2.0L 4G64 I4, FWD)
• 1990 Plymouth Colt (GT, 2.0L 4G63 I4, FWD)
• 1990-1994 Plymouth Laser (Base, RS, 2.0L 4G63/4G64 I4, FWD/AWD)

Fitment Notes

• Fits 6-bolt crankshaft engines ONLY. Does not fit 7-bolt 4G63 engines used in 1992.5-1994 and all 2nd Gen (1995-1999) DSM vehicles.
• The 6-bolt to 7-bolt engine transition occurred mid-1992 production year; verify crankshaft bolt pattern before ordering.
• 4G63 and 4G64 main bearings share the same part number for the 6-bolt platform.
• STDX designation = standard journal diameter crankshaft with +0.001" extra oil clearance for performance applications.
• Not for use with undersized or reground crankshafts - see MB5227XP010X, MB5227XP020X for undersize variants.
• Mitsubishi Tredia (1983) fitment is for the early 4G63 pre-DSM application; confirm engine displacement and crank bolt count before installation.

Features

• pMaxBlack™ tri-metal structure featuring an intermediate layer with 4.5% tin content - 22% harder (115 HV) than conventional race bearings, with a load carrying capacity of 17,000 psi.
• pMaxBlack™ overlay uses 5% copper content with an innovative nano-scaled hardening process, achieving 14.5 HV hardness versus the industry standard 11-14 HV, providing 24% greater fatigue resistance.
• Bull's Eye Tolerance™ technology maintains wall thickness variation at ±0.0001" - significantly tighter than the industry standard of ±0.00025" - ensuring consistent oil clearance without selective fitting.
• Bearings are narrowed for large-radius crankshaft fillets, reducing edge loading and improving crankshaft-to-bearing contact for the 6-bolt 4G63/4G64 crank geometry.
• Enlarged, chamfered oil holes with 3/4 groove pattern on upper shells for improved oil distribution and lubrication across all journal surfaces under high RPM and boost conditions.
• SecureBond adhesion process provides superior inter-layer bonding stability, preventing delamination under extreme thermal and mechanical cycling common in forced-induction DSM builds.
• Greater main bearing shell height improves bearing-to-bore contact area and heat transfer, directly reducing the risk of bearing spin at high RPM - critical for high-horsepower 4G63 applications.
• Single-set fitment capability: the STDX extra-clearance specification eliminates the need to purchase multiple sets to achieve desired oil clearance, streamlining the engine build process.
• Race-validated construction proven in circle track, off-road, and offshore competition - designed for sustained high-load, long-duration engine operation.

Specifications

• Part Number: MB5227XPSTDX
• Bearing Type: Main bearing set (crankshaft)
• Engine Application: Mitsubishi 4G63 / 4G64 - 6-bolt crankshaft platform
• Material: Tri-metal - steel backing / copper-lead intermediate with nickel barrier / lead-tin-copper Babbitt pMaxBlack™ overlay
• Size: STDX - standard journal diameter, +0.001" extra oil clearance
• Wall Thickness Tolerance: ±0.0001"
• Intermediate Layer Load Capacity: 17,000 psi
• Overlay Hardness: 14.5 HV
• Groove Style: 3/4 groove (upper shells)
• Oil Hole: Enlarged and chamfered for improved flow
• Bearing Width: Narrowed for large-radius crankshaft fillets
• Position: Main (crankshaft) - journals 1 through 5

Included Components

• 5x Main bearing shells (upper and lower pairs for all 5 main journals)

Product Description

The King MB5227XPSTDX is a race-grade XP-Series crankshaft main bearing set engineered specifically for the Mitsubishi 6-bolt 4G63 and 4G64 engine platform found in 1st Generation DSM vehicles - including the Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Mitsubishi Galant. These bearings are built around King's pMaxBlack™ tri-metal architecture, which combines a steel backing with a copper-lead intermediate layer featuring elevated tin content for dramatically higher load capacity, topped by a nano-hardened overlay that provides fatigue resistance beyond anything achievable with conventional race bearing materials. The STDX designation means the bearing ships at standard journal diameter sizing with a +0.001" additional oil clearance built in - eliminating the guesswork of shimming or selective fitting during assembly and making them an ideal choice for performance rebuilds targeting improved oil pressure stability at high RPM.

For builders pushing the 6-bolt 4G63 or 4G64 platform under forced induction, the MB5227XPSTDX addresses the most common failure modes of the stock and conventional aftermarket bearings. King's narrowed bearing design accommodates the large-radius crankshaft fillets of the 6-bolt crank, preventing edge stress concentration that can lead to premature fatigue and spalling. The 3/4-grooved upper shells with enlarged, chamfered oil holes ensure consistent oil film development across the entire journal surface even under the extreme loads generated by high-boost 4G63T builds. This bearing set is a direct-fit replacement requiring no machining beyond standard journal preparation and meets the demands of circle track, drag, and street/strip performance applications.

It is critical to confirm your engine uses the 6-bolt crankshaft before ordering. The 4G63 transitioned from the 6-bolt to the 7-bolt crankshaft design mid-way through the 1992 production year; the 7-bolt application requires a different bearing set. For standard journal crankshafts in good condition, the STDX clearance specification is the recommended choice. If the crankshaft has been reground, select the appropriate undersize variant (010X, 020X) to match the machined journal diameter. These bearings are intended for race and performance use and are sold as a complete set of 5 shells covering all main journal positions.