Clevite MS459P20 Clevite77 P-Series Crankshaft Main Bearing Set -.020" Undersize

The Clevite MS459P20 is a Clevite 77 P-Series TriMetal crankshaft main bearing set in -.020" (20 thousandths) undersize, designed for engine rebuilds requiring precision-fit undersized bearings to accommodate reground or worn crankshaft journals.

Part of the legendary Clevite 77 bearing family, the P-Series TriMetal design features a hardened precision steel backing, an intermediate cast copper-lead alloy layer, and an electroplated lead-tin-copper overlay. This tri-metal construction delivers superior conformability, embedability, and fatigue resistance compared to OEM and competitive bimetal bearings.

Key Features:

• P-Series TriMetal construction — steel back, copper-lead alloy intermediate layer, and electroplated overlay for maximum durability
• -.020" undersize — engineered for use with crankshafts that have been reground .020" under standard journal diameter
• High crush design for improved bearing seating and retention in the housing bore
• High eccentricity to accommodate rod bore distortion common in high-performance and high-mileage engines
• Cast copper-lead substrate increases fatigue strength approximately 20% over powdered metal (sintered) processes used by competitors
• Meets or exceeds OE specifications for fit, form, and function
• Suitable upgrade from bimetal bearings due to increased load capacity of the TriMetal design
• Ideal for street performance, heavy duty, and motorsports engine rebuilds

Clevite, now part of MAHLE, has been the industry standard in replacement and performance engine bearings since 1948. The P-Series is the most versatile bearing in the Clevite lineup, equally at home in stock rebuilds and demanding high-performance applications.