ACL Race Series Engine Bearings - 4B8351H-.025

If you're looking to boost the performance of your Mazda 323 (1986-2003) or Mazda Protege (1990-2003), the ACL Race Series Engine Bearings are engineered specifically for high RPM conditions, making them a perfect upgrade for your build. With a unique blend of advanced design, metallurgy, and engineering, these Trimetal engine bearings are built to meet the expectations of serious drivers who demand reliability and performance.

Why Choose ACL Race Series Bearings?

When you're pushing your vehicle to the limit, you need components that can keep up. The ACL Race Series Engine Bearings are designed with the following features:

• High-strength overlay plate with reduced thickness enhances fatigue resistance, ensuring longevity under pressure.
• Hardened steel backs on all rod bearings provide superior support for the bearing lining, improving retention within the housing.
• Increased crush for better bearing retention, giving you peace of mind during hard driving.
• Elimination of flash plating on the back of the bearings enhances heat transfer, maximizing grip between the bearings and their housing.
• Increased eccentricity compensates for bore distortion at high RPM, facilitating the formation of hydrodynamic oil films.
• 3/4 grooved main bearings optimize load-carrying surface area and oil flow to the conrod bearings, crucial for high-performance applications.
• Tight and consistent wall tolerances help maintain precise clearances, which is vital for engine performance.
• Enlarged ID chamfers accommodate larger fillet radii on performance crankshafts, making installation smoother.

Technical Specifications

• Size Options: STD, .025, .25, .50
• Oil Clearance: Standard
• Half Type: Upper & Lower
• Material: Tri-metal Hardened Steel Backs
• Min Standard Shaft Size: 1.7693in / 44.94 mm
• Max Standard Shaft Size: 1.7699in / 44.956 mm
• Min Standard Tunnel Size: 1.8896in / 47.996 mm
• Max Standard Tunnel Size: 1.8904in / 48.016 mm
• Max Wall at Crown: 0.0596in / 1.515 mm
• Max Overall Length: 0.6693in / 17 mm

Fitment

These bearings are designed to fit:

• Mazda 323: 1986-2003
• Mazda Protege: 1990-2003

Customer Feedback

One Mazda 323 owner shared, "After installing the ACL Race Bearings, I noticed a significant difference in how my engine revs. It feels much more responsive, especially when I push it past 6,000 RPM. I trust these bearings to hold up during track days!"

Another Protege driver commented, "These bearings fit perfectly and gave me the confidence to take my car to the next level. I can feel the difference in oil flow and overall performance."

Upgrade your engine with the ACL Race Series Engine Bearings and experience the difference in performance and reliability. Designed for serious drivers, these bearings are a must-have for your Mazda build.