ACL Race Main Bearings Set Subaru EJ20/EJ22/EJ25 (Thrust Position 5)

King Racing Main Bearings – 5M8309H Series (STD, 0.025, 0.25, 0.50)

King Racing 5M8309H main bearings are a performance replacement for standard main bearings in engines that use the 5M8309H-series shell. They use a tri-metal construction with an F780 alloy overlay and a hardened steel back for fatigue resistance under high RPM, heat and load. A 3/4 groove design improves oil flow through to the conrod bearings, and enlarged ID chamfers suit aftermarket crankshafts with large fillet radii.

This listing covers

• Engines using King 5M8309H-series main bearings
• High-performance and motorsport engine builds
• Available in STD, 0.025, 0.25 and 0.50 sizes

Note: For engines requiring additional oil clearance, HX versions are also available (for example, 5M8309HX).

What you'll also need

• Crankshaft journal and main tunnel measurements to confirm the correct size and resulting oil clearance before assembly

Specifications

• Material: F780 tri-metal
• Oil clearance: factory specification
• Minimum standard shaft size: 59.984 mm
• Maximum standard shaft size: 60.000 mm
• Minimum standard tunnel size: 64.000 mm
• Maximum standard tunnel size: 64.020 mm
• Maximum wall at crown: 2.005 mm
• Overall length: 22.92 mm (8309H)
• Half type: identical halves
• Available sizes: STD, 0.025, 0.25, 0.50
• Hardened steel back for housing support and retention
• 3/4 groove main journal design
• Increased crush and consistent wall tolerances
• Enlarged ID chamfers for performance crankshafts
• No flash plating, for improved heat transfer and grip

Specifications listed are for the STD size. Installation and clearance measurement by a qualified professional engine builder is recommended.

Shop more: ACL Performance Engine Bearings · ACL Subaru EJ & FA20 Engines (WRX, STI, BRZ & Toyota 86)

Need help choosing? Contact our team at sales@chicaneaustralia.com.au.