What does the +0.50mm sizing mean for these bearings?

The +0.50mm sizing indicates that these bearings are intended for use when the crankshaft journals have been machined down by 0.50mm. This is a common practice during engine rebuilds to clean up wear or damage on the original crankshaft.

What is the construction of these main bearings?

These main bearings are constructed with a bimetal material that has an aluminum base. This type of construction is chosen for its ability to manage heat effectively and resist wear in demanding engine applications.

Are these bearings compatible with all BMW engines?

No, these bearings are specifically designed for certain BMW engine families, including the M20, M50, and M52 series. It is important to verify that your vehicle is equipped with one of these compatible engine codes before purchasing.

Specifications

Brand: King Engine Bearings
Part #: MB7720AM0.5
UPC: 611500209321

King Engine Bearings BMW M20B20/M20B25/27/M50B20/25/M52B20/25/28 (Size +0.50mm) Main Bearing Set

Name: King Engine Bearings BMW M20B20/M20B25/27/M50B20/25/M52B20/25/28 (Size +0.50mm) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-bmw-m20b20-m20b25-27-m50b20-25-m52b20--t14-771096
Price: 124.76 USD
Availability: BackOrder

$124.76

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King Engine Bearings Main Bearing Set MB7720AM0.5. Bimetal aluminum base construction for BMW M20, M50, M52 engines.

Key Features

Fits 19+ vehicle make/model combinations including BMW M20, M50, and M52 engines.
Main bearing set is sized +0.50mm for use with machined crankshaft journals.
Features a bimetal construction with an aluminum base for heat and wear management.
Designed for BMW engines such as M20B20, M20B25/27, M50B20/25, and M52B20/25/28.

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About this part

Product Details

This main bearing set from King Engine Bearings features a bimetal construction with an aluminum base, a design choice that helps manage heat and wear in performance BMW engines. These bearings are sized +0.50mm, meaning they are intended for use when the crankshaft journals have been machined down by 0.50mm to clean up wear or damage. This set is designed to fit a range of popular BMW engines, including the M20B20, M20B25/27, M50B20/25, and M52B20/25/28 variants found in models like the E30 325i, E36 328is, and E39 525i.

King Engine Bearings is known for their well-built components, and this set is no exception. The bimetal material offers good compatibility with various oil types and provides a solid foundation for engine longevity. When rebuilding or refreshing an engine, using bearings that are correctly sized for the machined crankshaft is crucial for establishing proper oil clearance and ensuring the crankshaft spins freely without excessive play. This +0.50mm sizing is a common requirement after a performance rebuild or when addressing wear on the original crankshaft journals.