ACL bearings are used for tuning and engine upgrades where you want better quality with higher bearing capacity than normal standard bearings. Improvements of material, dynamic thickness, heat conduction, oil grooves and oil distribution are some of the points that make ACL one of the leading bearing manufacturers. Bearing data Part number: 6B1584H Bearing size: .25 Bearing half type: Upper & lower Bearing material: F781 Technical data (mm) Max overall length: 17.55 Max shaft size: 49.993 Max tunnel size: 53.616 Max vertical oil clearance: 0.103 Max wall at crown: 1.793 Min shaft size: 49.973 Min tunnel size: 53.6 Min vertical oil clearance: 0.055 Technical data (in) Max overall length: 0.6909 Max shaft size: 1.9682 Max tunnel size: 2.1109 Max vertical oil clearance: 0.0041 Max wall at crown: 0.0706 Min shaft size: 1.9674 Min tunnel size: 2.1102 Min vertical oil clearance: 0.0022 Engine code N54B30 / N55B30 / S55B30 Application BMW N54B30 2979cc Inline6 DOHC 4v Twin Turbo BMW N55B30 29