If you're looking to push your engine's performance to the next level, you might want to check out these ACL Race Series Engine Bearings. They’re not just another set of bearings; they’re crafted specifically for those high RPM situations that can really put the squeeze on your engine. Whether you’re working with a 4, 6, or 8 cylinder setup, these bearings have you covered. I've used them in my own projects, and I can tell you—they hold up under pressure.

One of the standout features is the high-strength overlay plate. It’s thinner than what you might find in standard bearings, which actually helps reduce fatigue. Trust me, that’s a big deal when you're pushing your engine hard. The hardened steel backs on all the rod bearings give you that extra support and help keep everything in place, so you won’t have to worry about them slipping out of the housing. Plus, they’ve upped the crush factor, which means better retention overall.

Another cool aspect is the elimination of flash plating on the back. This isn’t just a minor tweak; it significantly improves heat transfer, which is crucial when you’re running your engine hot. And if you're worried about bore distortion at high RPMs, the increased eccentricity helps create those hydrodynamic oil films that keep everything lubricated and running smoothly.

Speaking of oil flow, the 3/4 grooved main bearings are designed to optimize load carrying and ensure that oil gets where it needs to go—especially to the conrod bearings. Consistent wall tolerances mean you can maintain reliable clearances, which is essential for performance builds. And if you’re working with performance crankshafts, the enlarged ID chamfers on the bearing edges accommodate larger fillet radii without a hitch.

Now, let’s talk specs for a minute. These bearings come in a variety of sizes—STD, .025, .25, and .50, with standard oil clearance. They’re half type, so you’ll get both upper and lower bearings. Made from tri-metal with hardened steel backs, they’re built to last. You’ll want to keep an eye on the shaft sizes too; they fit a range from 2.0847 inches to 2.0852 inches. For tunnel sizes, you’re looking at 2.2305 inches to 2.231 inches, with a max wall thickness of 0.0720 inches and an overall length of 0.787 inches.

These bearings are a perfect fit for a bunch of Nissan models, including the Pulsar from 1987 to 2005 and the Sentra from 1982 to 2018. If you’re running a Nissan 4 cylinder engine with the CA16/18/20 setup, these .25 oversized main bearing sets are exactly what you need to keep your ride performing at its best.