ACL Main Bearings

2020 Toyota GR Supra 3.0L Inline 6 (B58B30/S58B30)

7M1512H-.25

Overview:

The ACL Main Bearings .25mm Oversized set is engineered specifically for the Toyota GR Supra 2020 model equipped with the BMW B58B30 and S58B30 3.0L inline six-cylinder engines. Designed to provide precise fitment and enhanced durability, these main bearings are ideal for enthusiasts and professionals seeking reliable engine rebuild components. The .25mm (0.010") undersize dimension ensures proper clearance and optimal oil film thickness, critical for maintaining engine health under demanding conditions.

Whether you are performing a routine rebuild or upgrading your engine for higher performance, ACL main bearings offer superior protection against wear and fatigue, helping to extend engine life and maintain smooth operation.

Key Features:

ACL main bearings are crafted with advanced technology and materials to meet the rigorous demands of modern high-performance engines. Key features include:

• Precision-engineered .25mm undersize to ensure exact fitment and optimal bearing clearance
• High-quality tri-metal construction for excellent load capacity and wear resistance
• Superior fatigue strength to withstand high RPM and increased power output
• Optimized surface finish for improved oil retention and reduced friction
• Compatibility with BMW B58B30 and S58B30 engines used in the 2020 Toyota GR Supra
• Manufactured to meet or exceed OEM specifications for reliability and performance
• Ideal for engine rebuilds, repairs, and performance upgrades

Construction & Design:

ACL main bearings utilize a tri-metal design consisting of a steel backing, a copper-lead intermediate layer, and a soft overlay to provide a balance of strength, conformability, and embedability. This construction allows the bearings to absorb small debris particles without damage and conform to slight imperfections in the crankshaft journal surface.

The .25mm undersize dimension is carefully controlled to maintain proper oil clearance, which is essential for creating a hydrodynamic oil film that prevents metal-to-metal contact. The bearing surfaces are finished with precision grinding and polishing to enhance oil flow and reduce friction, contributing to improved engine efficiency and longevity.

Installation & Fitment:

These main bearings are designed for direct replacement in the 2020 Toyota GR Supra models powered by the BMW B58B30 and S58B30 3.0L inline six engines. Installation requires standard engine rebuild procedures, including proper cleaning of bearing seats and journals, measuring journal diameters, and verifying bearing clearances with plastigage or micrometers.

No modifications are necessary when using this .25mm undersize bearing set, provided the crankshaft journals have been machined accordingly. It is recommended to follow factory service manual guidelines or consult a professional engine builder to ensure correct installation and optimal engine performance.

What's Included:

• Complete set of ACL main bearings sized at .25mm undersize
• Bearings for all main journals of the B58B30/S58B30 engine
• Packaging and documentation for identification and installation reference

Ideal For:

This ACL main bearing set is ideal for automotive enthusiasts, professional engine builders, and mechanics performing engine rebuilds or upgrades on the 2020 Toyota GR Supra with the BMW B58B30 or S58B30 engines. It is especially suited for those requiring precise bearing clearances after crankshaft undersizing or machining, ensuring reliable engine operation under both street and track conditions.

ACL Race Series is known for performance engine bearings used across motorsports, with rod and main bearing options engineered for durability under high load and heat. Their positioning centers on racing-focused design, metallurgy, and engineering intended to stand up to demanding competition engines.