The ACL RACE Series performance engine bearing range of today has a strong pedigree in motorsport & traces its roots back to the 1960’s with the manufacture of engine bearings for use in the world conquering Brabham Formula 1. Further experience in the Australian Supercars Championship & numerous other race codes has culminated in the current ACL RACE Series technology platform. The unique combination of design, metallurgy, engineering & precision quality control come together to deliver what engine builders expect from performance engine bearings

ACL Race Series performance engine bearings are manufactured to exacting tolerances. Micron tolerance machining supported by precision measurement systems delivers consistent accuracy to key characteristics like wall thickness and crush. This ensures reliable fit and helps maintain consistent clearances.

1 - High strength overlay plate with reduced thickness for improved fatigue properties 2 - Hardened steel backs on all rod bearings to improve the support of the bearing lining and assist with bearing retention in the housing 3 - Increased crush for improved bearing retention 4 - Elimination of flash plating on the back of the bearings to improve heat transfer through the bearings and to maximize the grip between the bearings and its housing. 5 - Increased eccentricity to compensate for bore distortion at high rpm and to assist in the formation of hydrodynamic oil films 6 - 3/4 grooved Main Bearings to optimize bearing load carrying surface area and oil flow to the conrod bearings 7 - Tight consistent wall tolerances to help you maintain consistent clearances 8 - Enlarged ID chamfers on bearing edges where required to accommodate large fillet radius on performance crankshafts

What is HX/STDX bearing?

Suitable for high to extreme power applications where additional clearance is beneficial in providing:

1 - Additional oil flow through the bearings to both improve delivery to high load zones and enhancing cooling.

2 - Allowing for increased housing distortion under very high inertial and firing loads.

3 - Providing space for specialised anti-friction coatings that beneficially moderated bearing to shaft surface interactions.

source: aclraceseries.com