What does the +0.25mm sizing mean for these bearings?

The +0.25mm sizing indicates that these bearings are intended for use when the crankshaft journals have been machined down by 0.25mm. This is a common practice during engine rebuilds to clean up wear or damage on the crankshaft surfaces.

What is the SX material used in these bearings?

The SX material is a high-performance tri-metal bearing material developed by King Engine Bearings. It's known for its strength, durability, and ability to maintain a consistent oil film, which is crucial for protecting the crankshaft.

Do these bearings come with installation hardware?

This set includes the main bearings only. It does not include any additional installation hardware or crankshaft seals. Always refer to the manufacturer's installation instructions for any required additional parts or procedures.

Specifications

Brand: King Engine Bearings
Part #: MB7792SX0.25
UPC: 611500626869

King Engine Bearings Porsche 911 M97 (Size +0.25mm) Main Bearing Set

Name: King Engine Bearings Porsche 911 M97 (Size +0.25mm) Main Bearing Set
Brand: King Engine Bearings
SKU: king-engine-bearings-king-engine-bearings-porsche-911-m97-size-0-25mm-main-beari-t14-771103
Price: 92.28 USD
Availability: BackOrder

$92.28

On Backorder — Expected to ship by Jul 24, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

King Engine Bearings Porsche 911 M97 Main Bearing Set. This +0.25mm set is crucial for engine rebuilds.

Key Features

This is a +0.25mm undersize main bearing set for Porsche 911 M97 engines.
Features King's SX tri-metal material for improved strength and durability.
Designed to maintain proper oil clearance after crankshaft journal machining.
Direct replacement for stock main bearings when journals are machined to size.

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About this part

Product Details

If you're rebuilding the engine in your Porsche 911 with the M97 engine, getting the main bearings right is a critical step. These main bearings from King Engine Bearings are designed to be a direct replacement for your stock bearings, but they come in a +0.25mm size. This means they're intended for use when the crankshaft journals have been machined down by 0.25mm to clean up wear or damage, ensuring a proper fit and oil clearance.

King Engine Bearings are known for their well-built construction. This set uses their SX material, which is a high-performance tri-metal material that offers excellent strength and durability. The design focuses on maintaining consistent oil film thickness, which is essential for protecting your crankshaft and ensuring the longevity of your engine rebuild. When installing, always refer to the manufacturer's specifications for proper torque and oil clearance to ensure these bearings perform as intended.