King Engine Bearings MB509HP020 Main Bearing Set for Chevrolet 400 V8 .020" Undersize

The King Engine Bearings MB509HP020 is a high-performance main bearing set specifically engineered for Chevrolet 400 cubic inch V8 engines. This HP-Series bearing set is designed for street and strip applications where extreme loads and demanding conditions are expected.

HP-Series Construction:

These bearings feature bi-metal silicon aluminum construction optimized for blown, turbocharged, nitrous oxide, and alcohol-fueled engines. The bearings are specifically designed to work with aftermarket crankshafts and include chamfered oil holes that accommodate the large radii typically found at the edge of aftermarket journal surfaces. Most main bearings in this set feature 3/4 grooving to enhance oil delivery to the rod journals under high-load conditions.

Key Features:

• HP-Series bi-metal silicon aluminum bearings for high performance applications
• .020" undersize thickness for use with turned-down crankshafts
• Chamfered oil holes designed for aftermarket crankshaft radii
• 3/4 groove configuration for improved oil flow to rod journals
• High-strength steel backing for maximum durability
• Ideal for drag racing, tractor pulling, and other high-load, short-duration applications
• Complete main bearing set for Chevrolet 400ci V8 engines

Application Note: The term "undersize" refers to the crankshaft journal diameter, not the bearing itself. These .020" undersize bearings are thicker than standard to compensate for crankshafts that have been machined down .020" during reconditioning. This set is engineered for high-load, short-duration motorsports applications including drag racing, monster trucks, and tractor pulling.