The ACL Race Series 6B1395HX-STD connecting rod bushes are designed for BMW N52 and N53 2.5- and 3.0-liter inline-6 engines. This HX version in STD sizes is designed to maintain a standard-size crankshaft while providing greater oil clearance than the H-STD bushes.
Developed for high-performance engines, the ACL Race Series features a trimetal design suited to the high stresses of the lower engine. The specific geometry of the HX version allows the engine builder to adjust the operating clearance without switching to a crankshaft repair size.
HX STD Version with Additional Oil Clearance
Part number 6B1395HX-STD has a maximum thickness at the top of 1.780 mm, compared to 1.793 mm for the 6B1395H-STD version. This difference provides approximately 0.025 mm of additional oil clearance across the diameter while maintaining standard-sized crankpins.
The HX STD version should therefore not be confused with a repair size. It addresses the needto adjust engine oil clearance during engine preparation and assembly.
ACL Race Series for BMW N52 and N53 Engines
These bearings are designed for 2.5- and 3.0-liter BMW N52 and N53 engines. ACL specifies a standard rod journal diameter between 49.973 and 49.993 mm and a bearing housing diameter between 53.600 and 53.616 mm.
The HX version should be selected after measuring the crankshaft, inspecting the connecting rod journals, and measuring the oil clearance. The required clearance depends on the configuration and tolerances used during engine assembly and should not be determined solely based on the desired power output.
Technical Specifications for ACL Race Series 6B1395HX-STD Bearings
Brand: ACL
Range: Race Series
Manufacturer Part Number: 6B1395HX-STD
Type: connecting rod bushes
Version: HX STD
Design: Tri-metal
Engine applications: BMW N52 and N53
Cubic capacity: 2.5 and 3.0 liters
Engine configuration: cylinders in line, 6
Crankshaft diameter: standard
Additional clearance: approximately 0.025 mm compared to the H-STD version
Standard rod journal diameter: 49.973 to 49.993 mm
Bore diameter: 53.600 to 53.616 mm
Maximum thickness at the top: 1.780 mm
Maximum width: 17.55 mm
ACL material: F781
Selection: based on crankshaft dimensions and required oil clearance
