The ACL 7M1397H-STD Race Series Main Bearing Set is designed for compatible BMW N54B30, N55B30, and S55B30 3.0L inline-six engines. This listing is for the standard-size version of ACL's high-performance crankshaft main bearing set.
ACL Race Series bearings are engineered for demanding performance and high-RPM engine applications. The H-series design uses performance-oriented bearing construction with tight manufacturing tolerances to help maintain consistent oil clearances and reliable crankshaft support under increased engine loads.
Features
- ACL Race Series high-performance main bearing set
- Designed for BMW N54B30, N55B30, and S55B30 3.0L engines
- Standard-size bearing set
- Performance-oriented H-series construction
- Designed for demanding turbocharged and high-RPM applications
- 3/4-grooved main bearing design to balance oil flow and load-carrying area
- Tight wall-thickness tolerances for consistent bearing clearance
- Designed to provide stable crankshaft support in performance engine builds
Engine Fitment
- BMW N54B30 3.0L Twin-Turbo Inline 6
- BMW N55B30 3.0L Turbo Inline 6
- BMW S55B30 3.0L Twin-Turbo Inline 6
Common Vehicle Applications
- BMW 135i
- BMW 1 Series M Coupe
- BMW 335i / 335is
- BMW 535i
- BMW 740i / 740Li
- BMW Z4 sDrive35i / sDrive35is
- BMW M2 Competition
- BMW M3 with S55 engine
- BMW M4 with S55 engine
Vehicle compatibility depends on the exact engine installed. Confirm your BMW uses a compatible N54B30, N55B30, or S55B30 engine before ordering.
Specifications
- Manufacturer: ACL
- Series: Race Series
- Part Number: 7M1397H-STD
- Base Bearing Set: 7M1397H
- Product Type: Crankshaft Main Bearing Set
- Bearing Size: Standard
- Engine Configuration: Inline 6
- Engine Displacement: 3.0L / 2979cc
- Engine Families: N54B30 / N55B30 / S55B30
Standard Size
This listing is for ACL part number 7M1397H-STD, the standard-size main bearing set. Standard-size bearings are intended for crankshaft journals that remain within the applicable standard dimensional specification.
Crankshaft journals and main bearing housing bores should be measured before selecting bearing size. Do not assume standard-size bearings are correct without verifying the engine's actual clearances and journal condition.
Recommended Use
- Performance BMW N54 engine builds
- Performance BMW N55 engine builds
- BMW S55 engine rebuilds
- Modified turbocharged engines
- High-RPM performance applications
- Engine rebuilds requiring standard-size main bearings
What’s Included
- 1 complete ACL 7M1397H-STD main bearing set
Installation
Main bearing installation requires precise crankshaft and housing measurements. Verify crankshaft journal dimensions, main housing bore dimensions, and oil clearances before final assembly. Follow the appropriate BMW and ACL engine-building specifications. Professional engine-builder installation is recommended.
Proposition 65 Warnings.
Cancer and Reproductive Harm. See details below.
Items that are not CARB Legal will not be sold and ship to California or CARB states.
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