What does '.50mm oversized' mean for these main bearings?

This means the bearings are designed to fit a crankshaft that has been machined down by 0.50mm (or 0.020 inches). This is typically done when the original crankshaft journals have wear or damage and need to be re-machined to a smaller diameter.

Are these bearings suitable for a standard, un-machined crankshaft?

No, these bearings are specifically sized for a crankshaft that has been machined to be 0.50mm undersize. If your crankshaft is at its original factory size, you will need standard size bearings.

What is the benefit of using ACL main bearings for an engine rebuild?

ACL is known for producing well-built engine components. These bearings are manufactured to precise tolerances, which is essential for maintaining proper oil clearance and oil pressure, helping to ensure the longevity and performance of your rebuilt engine.

ACL BMW N63B44/S63B44 4.4L V8 .50mm Oversized Main Bearings

Specifications

Brand: ACL
Part #: 5M1573H-.50
UPC: 9315726470213

ACL BMW N63B44/S63B44 4.4L V8 .50mm Oversized Main Bearings

Name: ACL BMW N63B44/S63B44 4.4L V8 .50mm Oversized Main Bearings
Brand: ACL
SKU: acl-acl-bmw-n63b44-s63b44-4-4l-v8-50mm-oversized-main-bearings-t14-719902
Price: 266.87 USD
Availability: BackOrder

$266.87

On Backorder

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Fits 2012-2018 BMW M6. ACL .50mm oversized main bearings for your 4.4L V8 engine. Essential for engine rebuilds.

Key Features

Fits 2012-2018 BMW M6.
Also fits 2009-2012 BMW 750i, 2013-2016 BMW M5, and 2011-2013, 2015-2018 BMW X5.
Set includes .50mm (0.020 inch) oversized main bearings.
Designed for BMW N63B44 and S63B44 4.4L V8 engines.
Manufactured by ACL, a well-known engine component supplier.
Crucial for engine rebuilds and crankshaft journal repair.

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Will this fit your vehicle?

Product Details

When you're rebuilding the engine in your BMW, especially one with the N63B44 or S63B44 4.4L V8, getting the right main bearings is critical. This set from ACL is .50mm oversized, meaning they are designed to fit a crankshaft that has been machined down by 0.020 inches. This is a common step when addressing wear or damage on the main journals to ensure a tight, proper fit for optimal oil pressure and engine health.

ACL is known for making well-built engine components, and these main bearings are no exception. They are manufactured to precise tolerances, which is crucial for maintaining consistent oil film and preventing metal-on-metal contact between the crankshaft and the engine block. Using bearings that are the correct size and specification helps ensure the longevity and performance of your rebuilt V8 engine.

This set is specifically sized for a .50mm undersize crank journal, so make sure your crankshaft has been machined to this specification before installation. If you're in the process of an engine overhaul for your BMW 750i, M5, M6, or X5, these ACL bearings are a solid option to consider for a reliable rebuild.