Race STD Size Conrod Bearing Set

The ACL Race Series 6B1490H-STD is a standard size conrod bearing set engineered for high-performance motorsports applications. These bearings are recognized for their endurance and capability in racing engines that have set records and won championships across various disciplines. The unique combination of design, metallurgy, and engineering ensures they can perform where other bearings cannot. Constructed with high-strength overlay plate, these bearings feature reduced thickness for improved fatigue properties. The hardened steel backs provide superior support for the bearing lining and assist with retention within the housing. Benefits include increased crush for improved bearing retention, elimination of flash plating on the back for better heat transfer and grip, and increased eccentricity to compensate for bore distortion at high RPMs and aid in hydrodynamic oil film formation. Additionally, the 3/4 grooved main bearings optimize load-carrying surface area and oil flow, while tight, consistent wall tolerances help maintain precise clearances. Enlarged ID chamfers are included where required to accommodate large fillet radii on performance crankshafts. These ACL Race Series conrod bearings are designed with identical halves and offer standard oil clearance. They are available in sizes STD, .025, .25, and .50. The specified dimensions include a minimum standard shaft size of 1.7707in / 44.975mm and a maximum of 1.7713in / 44.991mm, with a minimum standard tunnel size of 1.8898in / 48.000mm and a maximum of 1.8904in / 48.016mm. The maximum wall at the crown is 0.0588in / 1.493mm, and the maximum overall length is 0.709in / 18.00mm. This specific bearing set is compatible with various BMW engines including M20, M50, M52, and M54 variants, with specific applications listed for 2003-2015 BMW Z4 models. They are a direct replacement for standard size installations, ensuring a precise fit and optimal performance for your engine build.