If you're diving into the world of high-performance engines, you know that every little detail counts. That's where the ACL Race Series Engine Bearings come into play. These aren't just any bearings; they’re built for the serious driver who pushes their engine to the limit, whether you're working with a 4, 6, or 8-cylinder setup. Trust me, I've had my fair share of engine builds, and these bearings have become a staple in my toolkit.

What makes these bearings stand out? For starters, they've got a high-strength overlay plate that's thinner than what you might find elsewhere. This design choice isn’t just for show; it actually improves fatigue resistance, which is crucial when you're revving high. Plus, the hardened steel backs on all rod bearings provide solid support for the lining and help keep everything snug in the housing. You don’t want your bearings shifting around when you’re pushing your engine hard, right?

Another cool feature is the increased crush for better retention. It’s all about keeping those bearings where they need to be, especially under the stress of high RPMs. And speaking of high RPMs, the engineers have eliminated flash plating on the backs. This helps with heat transfer, ensuring that your bearings stay cool and maintain a solid grip in their housing. You’ll appreciate that when you’re pushing your ride on the track.

Now, let’s talk about eccentricity. Sounds fancy, but it’s really just a way to compensate for any bore distortion at those high speeds. This design helps in forming hydrodynamic oil films, which is key for keeping your engine lubricated and happy. And if you’re worried about oil flow, the 3/4 grooved main bearings optimize the load-carrying surface area, making sure that oil gets where it needs to go—especially to the conrod bearings.

Consistency is key in any performance build, and these bearings deliver with tight wall tolerances that help you maintain those crucial clearances. Plus, the enlarged ID chamfers on the edges accommodate larger fillet radii on performance crankshafts, which is a nice touch if you’re running a serious setup.

In terms of specs, you’ve got options for sizes like STD, .025, and .25. The oil clearance is standard, and the bearings come in identical halves. They’re made from tri-metal hardened steel backs, which means they’re built to last. For those interested in the nitty-gritty, the minimum standard shaft size is 2.3616 inches, and the maximum is 2.3622 inches. The tunnel sizes range from 2.5197 to 2.5205 inches, with a max wall thickness at the crown of 0.0789 inches and an overall length of 0.748 inches.

These bearings are a perfect fit for a range of Subaru models from 1990 to 2017, specifically for the EJ20, EJ22, and EJ25 engines. If you’re looking for a reliable, high-performance bearing set, this 0.75mm oversized main bearing set is definitely worth considering. It’s all about performance, durability, and keeping your engine running smoothly under pressure.