Function Plain bearings support and guide moving components inside the engine. Their primary purpose is to facilitate the virtually wear-free rotation of these components. Plain bearings comprise one or two bearing shells which are locked firmly in place in the bearing seat. The bearing shells wrap around the rotating shaft at the bearing journals.The wear on a plain bearing engine occurs when the engine is first started. On startup there is no oil flow or oil pressure so there is a minute amount of wear before the oil pressure comes up. Plain Bearings with no bushing are usually used for the camshaft in the cylinder head. There are several ways they are used.

Plain Bearings. The earliest blocks used plain bearings, but they have slowly given way to higher-performing bearings. Plain bearings have the least number of moving parts. A long lifespan and low maintenance with heavy load applications are the main benefits of plain bearings.