Clevite MS1343H H-Series Performance Main Bearing Set

The Clevite MS1343H is an H-Series high-performance main bearing set engineered for NASCAR-type racing and all forms of competition engines. These premium bearings feature a proven tri-metal construction with medium eccentricity, high crush for maximum retention, and a hardened steel backing for superior strength and durability.

H-Series Performance Features:

• Medium eccentricity design optimized for medium to high RPM operation
• High crush construction ensures positive bearing retention under extreme conditions
• Thin overlay reduces risk of overlay fatigue and "hen tracking"
• Enlarged chamfers provide greater crankshaft fillet clearance
• 180-degree upper shell grooving for optimal oil film development
• No flash plating for improved bearing seating
• Hardened steel back resists fretting and provides added strength

Engineering Advantages:

The H-Series design represents the ideal balance for most performance applications. The 180-degree groove in the upper main shell maximizes oil delivery to connecting rod bearings while maintaining the thickest possible oil film on the loaded lower bearing surface. This configuration provides superior bearing life compared to full-groove designs, which compromise oil film thickness and increase horsepower loss.

The medium eccentricity design produces optimal contact patterns covering 2/3 to 3/4 of the bearing surface—ideal for crankshafts with oversized fillets operating in the medium to high RPM range. If you're unsure which performance bearing series to choose, H-Series bearings are the recommended starting point for most racing applications.

Applications:

Best suited for competition engines with oversized fillet crankshafts, medium to high RPM operation, and applications requiring proven durability under extreme loads. The H-Series is Clevite's most versatile performance bearing line, suitable for circle track, road racing, drag racing, and high-performance street applications.