If you're diving into the world of high-performance engines, you know that the right components can make or break your ride. That’s where the ACL Race Series Engine Bearings step in. These aren’t just any bearings; they’re crafted with a unique blend of design, metallurgy, and engineering that truly delivers what you need for those high RPM conditions. Whether you’re working on a 4, 6, or 8 cylinder setup, these bearings are designed to handle the heat and pressure that comes with pushing your engine to its limits.

What sets these bearings apart? For starters, the high-strength overlay plate has a reduced thickness, which means better fatigue properties when you're really pushing your engine. The hardened steel backs on all the rod bearings provide solid support for the bearing lining, ensuring they stay put in the housing. And let’s talk about bearing retention—ACL has increased the crush, so you can trust they won’t be going anywhere when the RPMs start climbing.

Another cool feature is the elimination of flash plating on the back of the bearings. This little tweak significantly improves heat transfer, which is crucial when you're running hard. Plus, it maximizes the grip between the bearings and their housing, giving you that extra peace of mind. They’ve also increased the eccentricity to help compensate for any bore distortion at high RPMs, which is essential for forming those hydrodynamic oil films that keep everything running smoothly.

Now, if you’re worried about oil flow, you’ll appreciate the 3/4 grooved main bearings. This design optimizes the load-carrying surface area and ensures that oil flows efficiently to the conrod bearings. And with tight, consistent wall tolerances, you can maintain your clearances without any guesswork. They even enlarged the ID chamfers on the bearing edges to accommodate larger fillet radii on performance crankshafts. It’s these little details that make a big difference when you’re in the heat of the race.

Here’s a quick rundown of the specs, just so you know what you’re working with:

• Size: STD
• Oil Clearance: + 0.001" Extra
• Half Type: Identical Halves
• Material: Tri-metal Hardened Steel Backs
• Min Std Shaft Size: 1.8802 in / 47.758 mm
• Max Std Shaft Size: 1.8810 in / 47.778 mm
• Min Std Tunnel Size: 1.9921 in / 50.600 mm
• Max Std Tunnel Size: 1.9929 in / 50.619 mm
• Max Wall at Crown: 0.0548 in / 1.392 mm
• Max Overall Length: 0.0553 in / 19.00 mm

These bearings fit a range of Audi models too, including:

• Audi A3 (1998-2020)
• Audi A3 Quattro (2013 & 2015-2020)
• Audi A4 (1996-2013 & 2015-2022)
• Audi A4 Quattro (2017-2019)

So, if you’re looking to upgrade your engine’s performance, these ACL bearings are a solid choice. They’ve got the engineering to back them up, and you’ll feel the difference when you hit the gas.