Clevite MS-804H-20 High Performance Main Bearing Set H-Series

The Clevite MS-804H-20 is a high-performance main bearing set from the legendary H-Series line, designed specifically for competition engines and demanding racing applications. Originally developed for NASCAR-style racing, these bearings deliver the durability and precision required for high-RPM performance engines across all forms of motorsports.

H-Series Performance Features:

• Medium eccentricity design for optimal load distribution and contact patterns
• High crush specification ensures maximum bearing retention under extreme conditions
• Hardened steel backing provides superior strength and resistance to fretting
• Thin overlay construction prevents overlay fatigue and "hen tracking"
• Enlarged chamfers accommodate crankshafts with oversized fillets
• 180-degree upper shell grooving optimizes oil film thickness while feeding rod bearings
• Non-flash plated for improved seating and bedding characteristics

Advanced Oil Film Technology:

Clevite's H-Series bearings utilize optimized groove design based on extensive performance testing. The 180-degree groove in the upper main shell provides the best overall performance by maintaining thick oil film in critical load zones while ensuring adequate oil supply to connecting rod bearings. This design minimizes horsepower loss and peak oil film pressure compared to full-grooved alternatives.

Application Guidelines:

H-Series bearings are ideal for engines running in medium to high RPM ranges with crankshafts featuring oversize fillets. These bearings produce optimal contact patterns covering 2/3 to 3/4 of the bearing surface. If you're uncertain which performance bearing series to choose, H-Series bearings are the recommended starting point for most racing applications.

Built on Clevite's proven TriMetal construction with lead-tin-copper overlay, these bearings offer excellent wear resistance and durability. The MS-804H-20 set includes precision-manufactured upper and lower main shells engineered to withstand the severe demands of competition use.