– When it comes to choosing bearing shells for a performance application, it can be confusing. For example, why would you choose an aftermarket bearing shell, instead of the factory fitted bearing shells that came with your engine? Well when we’re producing a lot more power and running an engine to higher RPM than stock, there’s a lot more load being placed on the bearing shell, and it’s critical for reliability that that bearing shell can support the additional load. I just wanted to talk about a few features in aftermarket bearing shells, and in this case we’re at King Bearings and I wanted to look at their Subaru FA20 application. For a start the Subaru FA20 bearing shells, use King’s tri metal construction. This is what results in that black surface condition or finish that we can see. Often this is misunderstood as being a surface coating where in fact it’s actually a treatment that’s applied to the bearing shell. Now the tri metal construction that results in this black surface finish, in comparison to a conventional OE bearing shell, that’s usually a bi metal construction, reduces the imbedability of the surface layer of the bearing shell, and instead it improves the load handling capability. Now there are some pluses and some minuses with that sort of bearing construction. The load bearing capability as we’ve already discussed is essential for high horsepower applications, but this does reduce that imbedability. Now when the oil’s flowing through the engine, there’s always going to be some amount of debris present in the oil and it’s the job of that top surface layer of the bearing shell to trap this debris. This protects the journal surface of the crankshaft and prevents damage. So when we go to a tri metal construction, there’s less imbedability and this does reduce the service life of the bearing shell. So these are really suited to high horsepower, high performance applications that are going to at least see semi regular teardowns and rebuilds. The other problem with the Subaru FA20 engine is supplying sufficient oil to the big end bearing shells in order to remain reliable. Now King have dealt with this by adding an additional oiling hole to the main bearing shell, and this provides additional oil flow through to the big ends, improving the reliability of the big end bearing shells. Another feature that improves the oil supply as well, is King’s smart lug technology. The lug or locating tang on the main bearing shells that locates the bearing into the engine block, normally results in an indentation on the inside surface diameter of the bearing shell. This can be a source of oil leakage, and in turn this can reduce the oil pressure in the bearing shell. King deal with this with their smart lug technology where the tang or locating lug is pressed out through the back of the shell with no indentation on the internal surface. All of this adds up to improved oil pressure, improved oil supply, and more oil where it needs to be, protecting the bearing surface and the crankshaft journal. If you liked that video, make sure you give it a thumbs up and if you’re not already a subscriber, make sure you’re subscribed. We release a new video every week. And if you like free stuff, we’ve got a great deal for you. Click the link in the description to claim your free spot to our next live lesson. You’ll learn about performance engine building and EFI tuning and you’ll also have the chance to ask questions which I’ll be answering live. Remember it’s 100% free, so follow the link to claim your spot.