ACL 5M1857H-.25 Race Series Main Bearing Set Undersize - 0.25mm

The ACL 5M1857H-.25 is a Race Series performance main bearing set engineered for 5-cylinder engines requiring a 0.25mm undersize to accommodate a reground or undersized crankshaft. Designed for high-performance and competition applications, these bearings deliver the precision tolerances and superior load capacity demanded by built engines operating under elevated stress.

Key Features:

• Race Series construction — tri-metal overlay with copper-lead alloy for superior fatigue resistance and load capacity versus standard OEM bearings
• 0.25mm undersize — engineered for use with crankshafts that have been reground 0.25mm under standard journal diameter
• Tighter manufacturing tolerances — ACL Race Series bearings are manufactured to tighter-than-OEM specifications for improved oil film consistency and reduced crankshaft play
• High-performance bimetal/trimetal construction — aluminum tin or copper-lead overlay provides excellent conformability and embeddability
• 5-cylinder main bearing set — complete set for 5-cylinder engine applications
• Eccentricity control — precision-engineered for consistent oil clearance across all bearing surfaces

ACL Bearings are manufactured in Australia to strict quality standards and are a trusted choice among professional engine builders for both street performance and motorsport applications. The 5M1857H-.25 is ideal for any engine rebuild requiring an undersized main bearing with race-proven reliability.