ACL Bearings 5M909H-STD Race Series Main Bearing Set Standard Size

The ACL Race Series 5M909H-STD main bearing set delivers professional-grade performance for Chevrolet small block engines. This standard size set includes 5 precision-manufactured bearings designed to withstand high RPM conditions and demanding motorsports applications.

Advanced Tri-Metal Construction:

• Multi-layered tri-metal copper alloy construction provides exceptional strength and seizure resistance
• High-strength overlay plate with reduced thickness for improved fatigue properties
• Hardened steel backing for enhanced support and bearing retention
• Manufactured to exact tolerances ensuring reliable fit and consistent clearances

Performance Engineering Features:

• 1/2 groove design optimizes bearing load carrying surface area and oil flow
• Increased crush for improved bearing retention and heat dissipation
• Enhanced eccentricity compensates for bore distortion at high RPM
• Enlarged ID chamfers accommodate large fillet radius on performance crankshafts
• Flash plating eliminated on bearing backs to maximize heat transfer and housing grip
• Fits engines with housing bores of 2.100 inches

ACL Race Series bearings are trusted by championship-winning race teams across NASCAR, IHRA, and NHRA competitions. Manufactured in Tasmania, Australia with over 70 years of precision bearing expertise, these bearings represent the pinnacle of design, metallurgy, and engineering for high-performance engine builds.