Buyer’s Guide

Maximum Performance: Choosing the Best Engine Main Bearings

Automotive Performance Engine Main Bearings 1

When it comes to automotive performance engines, one of the most important components is the main bearings. These bearings are responsible for keeping the crankshaft in position and reducing friction between the crankshaft and engine block. Without a high-quality set of main bearings, your engine’s performance and durability can suffer greatly.

In this buyer’s guide, we’ll cover everything you need to know about automotive performance engine main bearings, from the different types available to the factors you should consider when purchasing a set. Let’s dive in!

Types of Main Bearings

There are two main types of main bearings: bi-metal and tri-metal. Bi-metal bearings are made of two layers: a steel backing and a layer of lead/tin alloy. Tri-metal bearings, on the other hand, have three layers: a steel backing, a copper-lead intermediate layer, and a lining of lead/tin alloy.

Bi-metal bearings are typically more affordable than tri-metal bearings, but they can have a shorter lifespan and may not be as effective at reducing friction. Tri-metal bearings, on the other hand, are more expensive but offer better durability and performance.


Main bearings can be made from a variety of materials, including:

– Lead/Tin: This is the most common material for main bearings, as it offers good wear resistance and reduces friction. However, it can be more prone to damage from debris or metal particles in the oil.

– Copper/Lead: Copper/lead bearings offer better durability than lead/tin bearings, but may not reduce friction as effectively.

– Aluminum: Aluminum bearings are lighter than other materials and can offer better resistance to high temperatures. However, they may not be as durable as other materials.

– Steel: Some main bearings are made entirely of steel, which can offer excellent durability and resistance to wear. However, they may not offer as much protection against friction.

Size and Fitment

When purchasing main bearings, it’s important to ensure that you select the correct size and fitment for your engine. Main bearings are available in standard sizes, as well as undersized and oversized options for engines that have been machined.

It’s also important to consider the clearance between the main bearings and the crankshaft. Too much clearance can result in excessive play, while too little clearance can cause the bearings to seize.

Performance Enhancements

If you’re looking to get the most out of your engine, there are a few performance enhancements you can consider when selecting main bearings. Some options include:

– Coatings: Main bearings can be coated with materials like molybdenum or Teflon to reduce friction and improve wear resistance.

– Grooving: Grooves can be added to the surface of main bearings to improve oil flow and reduce heat build-up.

– High-Performance Bearings: Some manufacturers offer high-performance main bearings that are designed to withstand extreme temperatures and high RPMs.


Purchasing the right set of main bearings is critical for ensuring that your automotive performance engine runs smoothly and lasts for years to come. By considering the different types available, materials, size and fitment, and potential performance enhancements, you can select a set that meets your specific performance needs and requirements.

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