What is the purpose of main bearings in an engine?

Main bearings are crucial components that sit between the crankshaft and the engine block. They support the crankshaft, allowing it to rotate smoothly while absorbing the significant forces generated during engine operation. Proper function is vital for engine longevity.

Why would I need oversized main bearings like these?

Oversized bearings, like this .025mm set, are typically used when the engine's crankshaft has been machined undersize. This machining is often done during an engine rebuild to correct wear or damage on the crankshaft journals. Using the correct oversized bearing ensures the proper oil clearance is maintained.

What is the significance of the ACL brand for engine bearings?

ACL is a well-known manufacturer in the automotive industry, particularly for engine bearings. Their products are recognized for being well-built and suitable for demanding applications, including performance and rebuilt engines.

2008-2013 BMW M3 Main Bearings | ACL .025mm Oversized 5M1581

Name: ACL BMW S65B40 4.0L V8 .025mm Oversized Main Bearings
Brand: ACL
SKU: acl-acl-bmw-s65b40-4-0l-v8-025mm-oversized-main-bearings-t14-719907
Price: 295.60 USD
Availability: BackOrder

ACL BMW S65B40 4.0L V8 .025mm Oversized Main Bearings

$295.60

On Backorder

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

Fits 2008-2013 BMW M3. ACL .025mm oversized main bearings for your S65B40 4.0L V8 engine. Essential for engine rebuilds.

Key Features

Fits 2008-2013 BMW M3.
Designed for the S65B40 4.0L V8 engine.
This set is .025mm oversized for use with a machined crankshaft.
Well-built main bearings from ACL.
Supports the crankshaft and maintains proper oil clearance.

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Product Details

For your 2008-2013 BMW M3 with the S65B40 4.0L V8 engine, these ACL main bearings are a critical component for any engine rebuild or repair. Main bearings sit between the crankshaft and the engine block, supporting the crankshaft and allowing it to spin smoothly while handling the immense forces generated during combustion. When rebuilding an engine, especially after a failure or for performance enhancements, replacing these bearings with a well-built set like these from ACL is essential for proper oil clearance and long-term engine health.

ACL has been a well-known name in engine bearings for a long time, and these main bearings are built to meet the demands of high-performance V8 engines. This specific set is .025mm oversized, which is important if your crankshaft has been machined undersize during a rebuild to correct wear or damage. Using the correct bearing size ensures the proper oil clearance, which is vital for lubrication and preventing premature wear. The material and precision manufacturing mean they can handle the stresses of the S65 engine.

When you're deep into an engine build, getting the right parts the first time saves a lot of headaches. These ACL main bearings are designed to fit your M3's specific engine, and using the correct .025mm oversized size is key if your crankshaft has been machined to match. Always refer to your vehicle's service manual for the correct installation procedures and torque specifications.