If you're diving into the world of high-performance engines, you know that every little detail counts. That’s where ACL Race Series Engine Bearings come into play. These aren’t just your run-of-the-mill bearings; they’re crafted with a unique blend of design, metallurgy, and engineering that really delivers when the rubber meets the road. Whether you’re revving a 4, 6, or 8-cylinder engine, these bearings are built to withstand the kind of RPMs that would make lesser parts weep.

One of the standout features is the high-strength overlay plate. It’s thinner than what you might find in standard bearings, which means it’s got improved fatigue properties. This is crucial when you’re pushing your engine to its limits. Plus, all the rod bearings come with hardened steel backs. This isn’t just for show; it provides solid support for the bearing lining and helps keep everything snug in the housing.

Let’s talk about grip. The design eliminates flash plating on the back of the bearings, which is a game-changer for heat transfer. Better heat management means your bearings can do their job without overheating and losing grip. And if you’re pushing your engine hard, you’ll appreciate the increased eccentricity that compensates for any bore distortion at high RPMs. This helps in forming those all-important hydrodynamic oil films that keep everything running smoothly.

Now, if you’re worried about oil flow, don’t be. The 3/4 grooved main bearings optimize the load-carrying surface area and ensure that oil gets to the conrod bearings where it’s needed most. With tight and consistent wall tolerances, you can maintain those crucial clearances without breaking a sweat. And for those of you with performance crankshafts, the enlarged ID chamfers on the bearing edges accommodate larger fillet radii, making installation a breeze.

When it comes to specs, these bearings are available in standard sizes of STD, .025, and .25, with a standard oil clearance. They feature identical halves made from tri-metal hardened steel backs, ensuring durability and reliability. The minimum standard shaft size sits at 2.0465" (51.980 mm), while the maximum is 2.0472" (52.000 mm). For tunnel sizes, you’re looking at a minimum of 2.1662" (55.021 mm) and a maximum of 2.1667" (55.034 mm). The max wall at the crown is 0.0591" (1.500 mm), and the overall length is 0.669" (17.00 mm).

These bearings fit a range of vehicles, including the Ford Escape from 2001 to 2018 and the Mazda Mazda 3 from 2004 to 2021. If you’re running a Ford or Mazda with a 2.3L engine, the 0.25mm oversized rod bearing set (part number 4B8170A-.25) is a solid choice to keep your performance up to par.