What does '+0.030 inch undersize' mean for these bearings?

This means the bearings are manufactured to be 0.030 inches smaller in diameter than a standard-sized bearing. This size is used when the engine's crankshaft has been ground down by 0.030 inches during a rebuild to remove wear or imperfections.

What is the material construction of these bearings?

These bearings utilize a tri-metal construction, featuring a copper-lead bearing material with a nickel barrier and a babbit overlay. This combination is chosen for its balance of strength, wear resistance, and ability to conform to the crankshaft.

Are these bearings suitable for a stock rebuild?

These bearings are designed for performance and durability, often used in performance or rebuilt engines. They are specifically sized for a crankshaft that has been machined to the +0.030 inch undersize specification, so they are not a direct replacement for standard-sized bearings in an untouched engine.

Specifications

Brand: King Engine Bearings
Part #: MB5293MC030
UPC: 611500619182

King Engine Bearings GM Vortec /LS-Series Gen III IV V (Size +0.030) Main Bearing Set

Name: King Engine Bearings GM Vortec /LS-Series Gen III IV V (Size +0.030) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-gm-vortec-ls-series-gen-iii-iv-v-size--t14-432453
Price: 100.61 USD
Availability: BackOrder

$100.61

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King Engine Bearings Main Bearing Set MB5293MC030. This is a +0.030 inch undersize set for GM Vortec and LS-series Gen III IV V engines.

Key Features

This is a +0.030 inch undersize main bearing set.
Features a high-performance overlay that is 0.0003 inches thick.
Built with a tri-metal material for improved strength and conformability.
Designed for GM Vortec and LS-series Gen III, IV, and V engines.

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About this part

Product Details

These main bearings are built with a high-performance overlay that's 0.0003 inches thick, designed to handle the demands of GM Vortec and LS-series Gen III, IV, and V engines. This specific set is machined to be 0.030 inches undersize, which is crucial when rebuilding an engine that has had its crankshaft ground down to match this size. The overlay material helps to reduce friction and wear, ensuring that your engine's rotating assembly runs smoothly and lasts longer.

King Engine Bearings uses a specialized tri-metal material for these bearings, combining copper-lead with a nickel barrier and a babbit overlay. This construction offers a good balance of strength and conformability, allowing the bearings to adapt to the crankshaft surface while providing solid load-carrying capacity. This is a popular choice for engine builders looking for a well-built bearing that offers improved durability over stock components.

When installing these bearings, it's important to follow the manufacturer's recommended torque specifications and to ensure the crankshaft journals are clean and properly measured. This set is intended for use with a crankshaft that has been machined to the +0.030 inch undersize specification.