What is the advantage of 'Extra Oil Clearance' bearings?

Extra oil clearance bearings allow for a larger volume of oil to flow between the bearing and the crankshaft. This is beneficial in high-performance or turbocharged engines where oil pressure might drop under load, ensuring the bearing surfaces remain adequately lubricated to prevent damage.

What does 'HX' mean in the part number?

The 'HX' in the ACL part number typically refers to their high-performance tri-metal bearing material. This construction offers a strong overlay combined with a conformable intermediate layer and a steel backing for durability and good oil performance.

Do I need to machine my crankshaft to use these standard size bearings?

These are standard size bearings, meaning they are intended for use with a crankshaft that is within factory specifications. If your crankshaft has been previously machined or is out of round, you may need to use undersize bearings instead. Always check your crankshaft's condition and specifications before ordering.

ACL BMW N54/N55/S55B30 3.0L Standard Size w/ Extra Oil Clearance Main Bearing Set

Specifications

Brand: ACL
Part #: 7M1397HX-STD
UPC: 9315726463086

ACL BMW N54/N55/S55B30 3.0L Standard Size w/ Extra Oil Clearance Main Bearing Set

Name: ACL BMW N54/N55/S55B30 3.0L Standard Size w/ Extra Oil Clearance Main Bearing Set
Brand: ACL
SKU: acl-acl-bmw-n54-n55-s55b30-3-0l-standard-size-w-extra-oil-clearance-main-bearing-t14-481515
Price: 311.90 USD
Availability: InStock

$311.90

Only 8 left in stock

Key Features

Fits select BMW 1 Series M, 135i, 335i, 335is, 335xi, 535i, 535xi, 740i, 740Li, X6, and Z4 models.
Designed for BMW N54, N55, and S55B30 3.0L engines.
Standard size bearings for a direct fit on a stock or machined crankshaft.
Features extra oil clearance to help maintain lubrication in high-performance and turbocharged applications.
Tri-metal construction provides a strong yet conformable bearing surface.
ACL is a popular manufacturer of engine bearings.

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Product Details

You get a full set of main bearings with extra oil clearance in this kit, which means you're ready to address bearing wear in your BMW's N54, N55, or S55B30 3.0L engine. These bearings are crucial for supporting the crankshaft and ensuring proper oil flow throughout the engine. When you're rebuilding or refreshing a high-performance engine like these BMW inline-sixes, getting the bearing clearances just right is key to reliability and longevity.

ACL is a well-known name in engine bearings, and this set is built to handle the demands of these powerful engines. The 'HX' designation indicates a tri-metal construction, which offers a good balance of strength and conformability to cushion the crankshaft. The 'STD' means they are standard size, and the 'Extra Oil Clearance' is important for turbocharged or high-revving applications where oil flow needs to be maintained even under extreme conditions. This extra clearance helps reduce oil pressure but ensures adequate lubrication to prevent seizure.

When installing these bearings, it's critical to follow the manufacturer's specifications for oil clearance and torque. You'll also want to ensure the crankshaft journals are clean and smooth. This set is a solid option for anyone rebuilding their N54, N55, or S55B30 engine and looking for reliable bearing performance.