What does it mean for these bearings to be undersized by 0.25mm?

An undersized bearing is meant to be used when the crankshaft journals have been machined down to remove wear or imperfections. This set is specifically 0.25mm smaller than a standard bearing to match a crankshaft that has been turned down by that exact amount.

What is the purpose of crankshaft main bearings?

Crankshaft main bearings are critical for the engine's bottom end. They support the crankshaft within the engine block, allowing it to rotate smoothly while maintaining a precise oil clearance to prevent friction and wear.

Do I need to replace the connecting rod bearings as well?

When rebuilding or refreshing an engine, it's generally recommended to replace both the main bearings and the connecting rod bearings at the same time. This ensures consistent oil clearance and wear characteristics throughout the rotating assembly.

FEATURED BRAND = COVERKING CHECK OUT COVERKING NOW →

Questions? Call Us:631-982-0042

M-F 8AM-4PM ET

Trusted Since 1957

Est. 1957

Specifications

Brand: ACL
Part #: 5M5647A-.25

ACL FORD 281 330 Engine Crankshaft Main Bearing Set

Name: ACL FORD 281 330 Engine Crankshaft Main Bearing Set
Brand: ACL
SKU: acl-acl-ford-281-330-engine-crankshaft-main-bearing-set-t14-632429
Price: 29.02 USD
Availability: BackOrder

$29.02

On Backorder

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

Fits 1999-2002 INFINITI G20. ACL Crankshaft Main Bearing Set 5M5647A-.25. Undersize 0.25mm.

Key Features

Fits 1999-2002 INFINITI G20.
ACL crankshaft main bearing set.
Part number 5M5647A-.25.
This set is undersized by 0.25mm for use with machined crankshaft journals.
Supports the crankshaft and maintains oil clearance.

Secure CheckoutFast Shipping631-982-0042

About this part

Product Details

Already running a built engine or looking to refresh your 1999-2002 INFINITI G20's bottom end? This ACL crankshaft main bearing set is a crucial component for ensuring smooth operation and proper oil clearance. These bearings sit between the crankshaft and the engine block, supporting the rotating assembly and maintaining the thin film of oil that prevents metal-on-metal contact.

This particular set is undersized by 0.25mm, meaning it's intended for use when the crankshaft journals have been machined down by that amount to clean up wear or out-of-round conditions. ACL is known for making well-built engine bearings, and this set is designed to meet the demands of a rebuilt or performance engine. Proper installation is key here; ensure your crankshaft journals are clean and within the specified tolerance for this undersize before installing these bearings.