Fits Popular GM LS Engine Platforms

The SI-Series standard-size main bearings are compatible with many Gen III and Gen IV LS engines, including:

• LS1
• LS2
• LS3
• LQ4
• LQ9
• L92
• L94
• L76
• L77
• LY6
• L96

Supported engine sizes include:

• 4.8L
• 5.3L
• 5.7L
• 6.0L
• 6.2L

This wide compatibility makes them ideal for LS swaps, stock rebuilds, and performance engine assemblies. What makes the LS1 vs LS2 vs LS3 argument so great? Check out our article here.

Ensure smooth crankshaft operation and reduced friction with this set of LS Main Crank Bearings, designed for stock and high-performance LS engine builds.

Designed for Stock and Performance Applications

Main crank bearings are responsible for supporting the crankshaft inside the engine block while maintaining proper oil film between rotating components.

The Michigan Motorsports SI-Series bearings are engineered for:

• OEM-style rebuilds
• Performance street engines
• Turbocharged LS applications
• Supercharged builds
• Drift and drag racing setups
• High-mileage engine refreshes

Fresh main bearings help ensure stable crankshaft operation and proper lubrication under both normal and high-load conditions.

Constructed from high-quality SI-Series bearing material, these standard-size main bearings provide excellent oil retention, increased load capacity, and superior heat dissipation.

Reliable Oil Control and Durability

High-quality main bearings help maintain:

• Consistent oil pressure
• Reduced crankshaft friction
• Proper oil clearance
• Stable crankshaft alignment
• Improved durability at higher RPM

These factors become increasingly important in modified LS engines where increased cylinder pressure and elevated RPM place additional stress on the rotating assembly.

Because “factory bearings looked okay” has launched countless engine rebuild threads across the internet.

Through the years, factory crankshaft bearings can wear down, leading to oil clearance issues, reduced engine efficiency, and potential crankshaft damage. These OEM-spec main bearings restore proper engine function, ensuring consistent oil glide and optimal bearing life. Perfect for day-to-day drivers, LS swaps, and high-horsepower builds, these bearings are designed to take care of increased engine loads whilst maintaining factory-level precision and smooth crankshaft rotation.

Built for LS Enthusiasts and Builders

Michigan Motorsports has become a trusted name within the LS community by offering affordable and dependable performance parts tailored specifically for GM LS platforms.

Their products are commonly used in:

• Street performance builds
• Engine swap projects
• Budget turbo LS builds
• Drift cars
• Truck rebuilds
• Drag racing applications

The SI-Series main bearings continue that reputation by offering reliable crankshaft support for both mild and aggressive LS engine combinations.

Premium LS Main Crank Bearings for Stock & Performance Builds – Designed to offer precision fitment and long-lasting durability, these SI-Series main bearings be sure smooth engine operation in OEM rebuilds and high-performance LS applications.
Standard Size for Direct Factory Replacement – Manufactured to exact OEM specifications, these bearings deal with proper oil clearance, reducing friction and wear for extended engine life and maximum efficiency.
Ideal for Engine Rebuilds & Performance Upgrades – Whether you’re restoring a high-mileage LS engine or building a performance block, these standard-size main bearings give you the durability and precision needed for long-term reliability.
High-Strength Bearing Material for Increased Load Capacity – Features tri-metal construction for superior heat dissipation, oil retention, and bearing longevity, making it ideal for day-to-day-driven vehicles and high-performance LS builds.
Compatible with a Wide Range of LS Engines – Fits Gen 3 & Gen 4 LS engines, including 4.8L, 5.3L, 5.7L, 6.0L, and 6.2L applications, ensuring reliable performance in naturally aspirated, turbocharged, and supercharged setups.

Smart Insurance During Engine Assembly

Replacing main bearings during an LS rebuild is one of the most important preventative maintenance steps you can take while the engine is apart.

Benefits include:

• Improved long-term reliability
• Better crankshaft protection
• Enhanced oil control
• Reduced wear on internal components
• Increased confidence under load

Especially in older LS engines with unknown mileage histories and questionable maintenance records, fresh bearings are cheap insurance compared to replacing a damaged crankshaft or complete short block.