Connecting rod bearings are a crucial component of an engine’s rotating assembly. They support the connecting rod on the crankshaft journal and help reduce friction between the two surfaces. The part numbers for these bearings typically have a string of numbers and letters that designate the specific size and type of bearing required for a particular engine. However, the last two digits in these part numbers can often be a source of confusion for mechanics and engine builders. So, what do these digits mean?

The last two digits in a connecting rod bearing part number usually indicate the thickness and/or clearance of the bearing. For example, a bearing with a part number ending in «21» might indicate a thickness of 0.021 inches, while a bearing ending in «25» might indicate a thickness of 0.025 inches. Additionally, the last two digits can sometimes signify the percentage of bearing material in relation to the backing material. For instance, a bearing ending in «30» might mean that 30% of the material is bearing alloy, while the remainder is steel.

It’s important to note that not all bearing manufacturers use the same numbering system, and some may have different meanings for the last two digits. Therefore, it’s crucial to consult with the manufacturer’s specifications when selecting and installing connecting rod bearings to ensure proper fit and performance.

In summary, the last two digits in connecting rod bearing part numbers can provide valuable information about the thickness, clearance, and material composition of the bearing. Understanding these designations and using them properly can help ensure the longevity and performance of an engine’s rotating assembly.

Connecting Rod Bearings: Deciphering the Part Numbers

When it comes to engine building and maintenance, one of the most crucial components is the connecting rod bearing. However, the part numbers associated with these bearings can leave many mechanics scratching their heads, particularly when it comes to the last two digits. In this article, we’ll explore what these numbers mean and how to use them to select and install the right bearings for your engine.