Clevite MS-1429G-.25MM High Performance Main Bearing Set .25MM Undersize

The Clevite MS-1429G-.25MM is a high-performance engine crankshaft main bearing set designed for demanding performance and racing applications. This bearing set features .25mm undersize dimensions for use with reground crankshafts, providing precision fitment and optimal oil clearance for modified engines.

Advanced Bearing Design:

Clevite main bearings utilize optimized groove configurations to balance oil delivery with bearing performance. The upper main shells feature a 180-degree groove design that efficiently supplies oil to connecting rod bearings while maintaining maximum oil film thickness on loaded surfaces. Unlike older full-grooved designs, modern Clevite lower main shells eliminate grooving to preserve the critical oil film that separates the bearing from the crankshaft, resulting in improved load capacity and extended bearing life.

TriMetal Construction:

These bearings feature Clevite's proven TriMetal construction with a steel backing, intermediate copper-lead alloy layer, and a lead-tin-copper overlay. This multi-layer design provides exceptional strength, excellent conformability, and superior wear resistance across a wide range of operating conditions.

Performance Features:

• High crush design ensures positive bearing retention in the housing
• Reduced overlay thickness prevents overlay fatigue and "hen tracking"
• Precision-manufactured for consistent quality and dimensional accuracy
• Engineered chamfers provide proper crankshaft fillet clearance
• No flash plating on steel back promotes improved seating characteristics
• Optimized eccentricity for proper bearing contact patterns

Application Guide:

This bearing set is ideal for performance street engines, racing applications, and engine rebuilds requiring undersize bearings due to crankshaft machining. The .25mm undersize dimension compensates for material removed during crankshaft grinding, restoring proper bearing clearances. Proper bearing selection, installation, and clearance checking are critical for optimal performance and longevity.

Clevite has been the trusted choice of engine builders and professional racers for decades, delivering the reliability and performance demanded by high-output engines operating under extreme conditions.