So, you’re diving into the world of performance engines, huh? If you’re looking to crank up the RPMs without worrying about your bearings giving out, let me tell you about these ACL Race Series Engine Bearings. They’ve got this killer blend of design and metallurgy that really stands out. Perfect for those who push their engines to the limit—these bearings are made for the serious driver.

What sets these bearings apart? For starters, the high-strength overlay plate has a reduced thickness, which means less fatigue when you’re really pushing your engine. And if you’re running a 4G63 or 4G64 engine from a Mitsubishi built between '97 and now, you’re in luck—these bearings are specifically designed for that setup.

• They come with hardened steel backs on all rod bearings. This isn’t just for show; it helps keep the lining in place and ensures they stick in the housing like they should.
• The increased crush improves how well the bearings hold onto the crankshaft, so no worries about them slipping out under pressure.
• Plus, they’ve eliminated flash plating on the back. This little tweak enhances heat transfer, which is a big deal when you’re running hot.
• And let’s talk about eccentricity—these bearings have it in spades. They compensate for any bore distortion at high RPMs, which helps maintain that all-important hydrodynamic oil film.
• The 3/4 grooved main bearings are a nice touch too; they optimize load carrying and oil flow to the conrod bearings. This means you get better lubrication where it counts.
• With tight, consistent wall tolerances, you can maintain those clearances without any guesswork.
• And for those of you with performance crankshafts, the enlarged ID chamfers on the bearing edges are designed to fit snugly around larger fillet radii.

Now, let’s get into the nitty-gritty specs. These bearings come in standard sizes (STD, .025, .25) and have a standard oil clearance. They’re available in both upper and lower half types, made from tri-metal with hardened steel backs. Here’s a quick rundown of the sizes:

• Min Std Shaft Size: 2.2435in / 56.985mm
• Max Std Shaft Size: 2.2441in / 57.000mm
• Min Std Tunnel Size: 2.4016in / 61.000mm
• Max Std Tunnel Size: 2.4024in / 61.021mm
• Max Wall at Crown: Std: 0.0783in / 1.990mm
• Max Overall Length: 0.8268in / 21.00mm

So if you’re ready to push your Mitsubishi to the next level without worrying about your bearings, these ACL Race Series Engine Bearings are a solid choice. They’re built for those who know what they want and aren’t afraid to go after it.