If you're diving into the world of high-performance engines, you need bearings that can keep up with your ambitions. The ACL Race Series Engine Bearings are crafted with a unique blend of design, metallurgy, and engineering that really delivers on performance. These aren't just your run-of-the-mill bearings; they're built to handle the heat and stress of higher RPMs, making them a solid choice for those who push their engines to the limit.

What sets these bearings apart? For starters, they've got a high-strength overlay plate that's thinner than what you usually find, which means better fatigue resistance. That’s crucial when you’re revving high and putting your engine through its paces. The hardened steel backs on all the rod bearings provide extra support for the lining, ensuring they stay put in the housing—no one wants to deal with a bearing that’s come loose mid-race.

Speaking of support, these bearings feature increased crush for better retention, and they’ve eliminated flash plating on the back. This little tweak helps with heat transfer and maximizes the grip between the bearings and their housing. Plus, they’ve got increased eccentricity to tackle any bore distortion that might happen at high RPMs, which is key for forming those hydrodynamic oil films that keep everything running smoothly.

And let’s not forget about the 3/4 grooved main bearings. This design optimizes the load-carrying surface area and ensures oil flows efficiently to the conrod bearings. With tight and consistent wall tolerances, you can maintain reliable clearances, which is essential for any engine build. The enlarged ID chamfers on the bearing edges are also a nice touch, accommodating those larger fillet radii found on performance crankshafts.

Now, if you’re curious about the nitty-gritty specifications, here’s what you need to know: these bearings come in sizes like STD, .025, .25, and .50, and they have standard oil clearance. They’re available as upper and lower half types and are made from tri-metal hardened steel backs. The minimum standard shaft size is 1.9661 inches, while the maximum is 1.9668 inches. For tunnel sizes, you’re looking at a minimum of 2.1259 inches and a maximum of 2.1267 inches. And just to give you a heads-up, the max wall at the crown is 0.0793 inches, with an overall length of 0.6941 inches.

These bearings fit a range of applications, including the Mazda MX-3 from '93 to '98 and the Mazda Protege from '90 to '03. Specifically, if you're working on a B6/BP/BP-T 1.6/1.8L engine, the 5M8353H-.025 ACL Mazda high-performance main bearing set is a great choice for .025mm oversized needs.

In short, if you’re serious about performance and want something that’s been engineered to last, the ACL Race Series Engine Bearings are worth considering. They’re built for those who don’t just want to drive—they want to dominate.