What is the CT-1 coating on these bearings?

The CT-1 coating is a dry film lubricant applied to the bearing surface. It helps to reduce friction and wear, particularly during the critical initial startup and break-in phases of a new or rebuilt engine.

Are these bearings suitable for a stock engine rebuild?

While these are high-performance bearings with a special coating, they are standard size and can be used in a stock engine rebuild if the crankshaft has not been machined undersize. They offer improved durability over basic bearings.

What is the difference between standard size and undersize bearings?

Standard size bearings are meant to be used with a crankshaft that is at its original factory specifications. Undersize bearings are used when a crankshaft has been machined down (ground) to correct imperfections or to achieve a specific clearance, and they are sized to match that machined dimension.

ACL Acura B17A1/B18A1/B18B1/B18C1/B18C5 Honda K20A3/K20A2/K24A Standard Size High Perf - CT-1 Coated

Specifications

Brand: ACL
Part #: 5M1959HC-STD
UPC: 9315726457702

ACL Acura B17A1/B18A1/B18B1/B18C1/B18C5 Honda K20A3/K20A2/K24A Standard Size High Perf - CT-1 Coated

Name: ACL Acura B17A1/B18A1/B18B1/B18C1/B18C5 Honda K20A3/K20A2/K24A Standard Size High Perf - CT-1 Coated
Brand: ACL
Price: 130.09 USD
Availability: InStock

$130.09

On Backorder — Expected to ship by Mar 29, 2026

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ACL High Perf engine bearings for Acura and Honda. Standard size, CT-1 coated. Part# 5M1959HC-STD.

Key Features

Fits various Acura and Honda B-series and K-series engines.
Standard size bearings for use with a factory-spec crankshaft.
Features a CT-1 dry film lubricant coating for reduced friction and wear.
Well-built by ACL, a known manufacturer of engine components.
Designed for high-performance engine builds.

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Will this fit your vehicle?

Product Details

If you're rebuilding the bottom end of your B-series or K-series engine, you're probably looking for a solid set of bearings to keep everything running smoothly. These ACL High Performance main bearings are built to handle the demands of a performance engine build. They feature a CT-1 coating, which is a dry film lubricant that helps reduce friction and wear, especially during initial startup and break-in periods. This coating is a notable upgrade over standard bearings, offering improved durability.

ACL has been making engine bearings for a long time, and these are well-built for performance applications. They are standard size, meaning they're meant to be used with a crankshaft that hasn't been machined undersize. The CT-1 coating is applied to help protect the bearing surface and the crankshaft journal, which is especially important when you've got increased oil flow or higher operating temperatures in a performance build. This coating helps ensure a solid foundation for your engine's rotating assembly.

This set includes main bearings for a variety of Acura and Honda models, covering popular engines like the B17A1, B18 series, and K20/K24 series. Make sure to check the fitment list to confirm they're the right ones for your specific engine build. When installing, always follow the manufacturer's recommended torque specifications and lubrication procedures to get the most out of these bearings.