ACL Race Main Bearings 5M1959H – Honda B16, B18, B20, K20, K24

Complete set of ACL Race main crankshaft bearings with the manufacturer’s part number 5M1959H. These high-performance bearings are designed for Honda B-series and K-series engines. Engineered for durability, precision, and consistent oil pressure, they are an ideal choice for tuned and high-revving engines.

Main Features

• High-strength tri-metal bearing material with excellent wear resistance
• Improved oil film stability under high load and temperature
• Precise fitment for OEM and forged crankshafts
• Designed for performance and racing applications

Applications

Suitable for the following Honda engines:

• B-series: B16A1, B16A2, B16A3, B17A1, B18A1, B18B1, B18C1, B18C4, B18C5, B18C6, B20B3, B20Z
• K-series: K20A2, K20A3, K20A4, K20A6, K20Z4, K24A1, K24A3, K24A4, K24A8

Technical Specifications

• Bearing diameter: 55 mm
• Bearing width: 20 mm
• Manufacturer: ACL Race Series
• Part number: 5M1959H

OEM Reference Numbers

These ACL Race main bearings replace the following OEM Honda part numbers:

13321-PR3-003, 13321-PR3-004, 13322-PR3-003, 13322-PR3-004, 13323-PR3-003, 13323-PR3-004, 13324-PR3-003, 13324-PR3-004, 13325-PR3-003, 13325-PR3-004, 13326-PR3-003, 13326-PR3-004, 13327-PR3-003, 13327-PR3-004, 13341-PR3-003, 13341-PR3-004, 13342-PR3-003, 13342-PR3-004, 13343-PR3-003, 13343-PR3-004, 13344-PR3-003, 13344-PR3-004, 13345-PR3-003, 13345-PR3-004, 13346-PR3-003, 13346-PR3-004, 13347-PR3-003, 13347-PR3-004, 13321-PNA-003, 13322-PNA-003, 13323-PNA-003, 13324-PNA-003, 13325-PNA-003, 13326-PNA-003, 13341-PNA-003, 13342-PNA-003, 13343-PNA-003, 13344-PNA-003, 13345-PNA-003, 13346-PNA-003, 13321-PRB-A01, 13322-PRB-A01, 13323-PRB-A01, 13324-PRB-A01, 13325-PRB-A01, 13326-PRB-A01, 13341-PRB-A01, 13342-PRB-A01, 13343-PRB-A01, 13344-PRB-A01, 13345-PRB-A01, 13346-PRB-A01, 13032-PR3-S10

Why Choose ACL Race Bearings?

ACL Race bearings are the choice of professional engine builders and tuners worldwide. They provide outstanding oil control, consistent clearance, and extended life under extreme conditions. Perfect for naturally aspirated, turbocharged, and high-RPM Honda engines.

FAQ – Frequently Asked Questions about ACL Race 5M1959H

1. Do these bearings require machine fitting?
Yes. As with all performance bearings, professional installation and precise clearance measurement are recommended.

2. Are they compatible with forged crankshafts?
Yes, ACL Race 5M1959H bearings fit both OEM and aftermarket forged cranks with a nominal diameter of 55 mm.

3. Is this a complete set for the entire crankshaft?
Yes, this is a complete set of main bearings for the entire crankshaft.

4. Can they be used in turbocharged engines?
Yes. Their high-strength tri-metal design ensures excellent durability and oil stability under boost and high-load conditions.