Engine bearings are one of the most important parts of the engine and require the utmost precision during production. High quality engine bearings can extend the life of an engine and reduce carbon emission . A main crankshaft bearing is a bearing in a piston engine which holds the crankshaft in place and allows it to rotate within the engine block. Connecting rod bearings in modern engines are plain bearings that support the connection rod on the bearing journal of the crankshaft. Transmitted by connection rod, main crankshaft bearings and connecting rod bearings are being subjected to heavy loads.