What is the advantage of the extra oil clearance on these bearings?

The extra 0.025mm of oil clearance helps maintain a stronger oil film between the crankshaft and the bearing, especially under high load or temperature conditions. This can be beneficial for engines that are driven hard or have been modified for performance.

Do these bearings require any special machining to install?

These are standard size main bearings, meaning they are designed to fit without requiring the crankshaft to be turned undersize. However, it is always recommended to check crankshaft journal tolerances and the condition of the block during an engine rebuild.

What other parts are typically needed when replacing main bearings?

When replacing main bearings, it's standard practice to also replace the connecting rod bearings. You'll also need new engine oil and oil filter, and potentially new main bearing bolts or studs depending on their condition and manufacturer recommendations.

ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings

Specifications

Brand: ACL
Part #: 7M1512HX-STD
UPC: 9315726470077

ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings

Name: ACL BMW B58B30/S58B30 3.0L Inline 6 Standard Size Main Bearings
Brand: ACL
Price: 267.93 USD
Availability: InStock

$267.93

On Backorder — Expected to ship by Mar 29, 2026

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

Fits 2016-2018 BMW 340i. ACL standard size main bearings for B58B30/S58B30 3.0L Inline 6 engines, offering an extra 0.025mm oil clearance for improved performance.

Key Features

Fits 2016-2018 BMW 340i, 2018-2019 BMW X3, and 2020 Toyota GR Supra.
Designed for BMW B58B30 and S58B30 3.0L inline-6 engines.
Standard size bearings for direct replacement.
Includes an extra 0.025mm (0.001 inch) of oil clearance for improved oil film strength.
Well-built by ACL for reliable engine performance.

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Fits these vehicles

BMW 340i 2016-2018
BMW X3 2018-2019
Toyota GR Supra 2020

Product Details

Doing an engine rebuild on your 2016-2018 BMW 340i, or perhaps a 2018-2019 X3 or a 2020 GR Supra? If you're working with the B58B30 or S58B30 3.0L inline-6 engine, you're likely looking at replacing the main bearings. These ACL main bearings are built to the original equipment specifications, ensuring a direct fit for your engine. They come in standard size, meaning they're designed to replace your worn bearings with minimal machining, though a proper engine rebuild typically involves checking tolerances.

What sets these ACL bearings apart is the extra 0.025mm of oil clearance they offer over stock. This slight increase helps to maintain oil film strength under higher loads and temperatures, which is crucial if you're pushing your engine harder or have made performance modifications. ACL uses well-built materials and manufacturing processes to create bearings that can handle the demands of these powerful BMW engines. They are a solid option when you need reliable internal engine components for a rebuild or performance build.

When installing main bearings, it's always recommended to follow the manufacturer's specific torque sequences and lubrication procedures. Ensure your crankshaft journals are clean and within factory specifications before installation to get the best performance and longevity from these ACL bearings.