Product Description
King MB5293SI SI-Series Standard Main Bearing Set for LS and LT Engines
Fits 1997–2024 4.8L, 5.3L, 5.7L, 6.0L and 6.2L Engines with Stock Crankshafts
Restore the main-bearing assembly in a compatible LS or LT engine with the King MB5293SI SI-Series standard-size main bearing set. Developed for stock replacement and mild-performance applications using a factory crankshaft, these direct-replacement bearings fit the supplied 1997–2024 4.8L, 5.3L, 5.7L, 6.0L and 6.2L engine applications.
King SI-Series bearings feature an improved surface finish designed to reduce microscopic peaks on nodular cast-iron crankshafts. Improved oil-clearance control helps reduce wear, operating noise, vibration and excessive oil flow, while the SI-Series top layer provides the embeddability needed to help isolate small foreign particles before they damage the factory crankshaft.
Key Features & Benefits
- King SI-Series Main Bearings: MB5293SI is engineered for stock replacement and mild-performance LS and LT engine combinations retaining a factory crankshaft. The SI-Series construction provides a direct-replacement bearing solution without moving to the HP or XP Series intended for aftermarket crankshafts.
- Standard-Size Main Bearing Set: This package contains a standard-size set of main bearings for compatible engines that have not been machined for undersized crankshaft bearings. The standard-size designation is an important distinction when selecting bearings for an LS or LT engine rebuild.
- Improved Bearing Surface Finish: King uses an improved finish intended to reduce microscopic surface peaks on compatible nodular cast-iron crankshafts. The refined bearing surface supports the needs of stock-crankshaft rebuilds and mild-performance engine combinations.
- Optimized Oil-Clearance Control: Improved oil clearance helps reduce bearing wear and supports longer engine service life. King’s SI-Series design also helps limit unnecessary operating noise, vibration and excessive oil flow within the supported factory-crankshaft applications.
- Embeddable SI-Series Top Layer: The bearing’s top layer offers strong embeddability, allowing small foreign particles to become embedded in the bearing surface. This characteristic helps prevent circulating debris from contacting and damaging the engine’s original crankshaft journals.
Notes
- Not for aftermarket crankshafts; use the appropriate King HP or XP Series bearing set for those applications.
- Not for Gen V engines equipped with Auto Start/Stop; use King MB5293MC coated main bearings for those applications.
- The thrust bearing does not include a locating tab. This is intentional because the thrust side walls locate the bearing front-to-rear in the block and cap saddles.
Key Fitments
- 1997–2024 LS and LT-based 4.8L, 5.3L, 5.7L, 6.0L and 6.2L engines with stock crankshafts
- LS1, LS2, LS3, LS6, LS4, L99 and LSA
- L92, L9H, L94, L76, L77, LY6, L96, LFA and LZ1
- LY5, LMG, LMF, LH6, LC9, LY2, L20, L33, LH8 and LH9
- LQ4, LQ9, LR4, LM7 and L59
- LT1, L83, L86, L84, L87 and L8B without Auto Start/Stop
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Product Reviews
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Excellent Quality Bearings for Rebuild
recently completed a full rebuild on the 6.2L L86 in my 2018 GMC Yukon XL Denali 4WD, and I used Michigan Motorsports for a large portion of the engine rebuild parts. The main goal of the rebuild was to address the factory DOD/AFM system and convert the engine to a mechanical DOD delete/non-AFM setup. I wanted to do it right while I had the engine completely apart rather than simply replacing the failed components and putting the factory system back in. Some of the Michigan Motorsports parts I used included: * King MB5293SI main bearings * Genuine GM 12735504 connecting rod bearings * Genuine GM 11548432 connecting rod bolts * Michigan Motorsports Gen V LT main cap bolt kit * 7.850” Gen V pushrods * Gen V camshaft bearings * Michigan Motorsports DOD/AFM delete components * Delphi LS7 non-DOD lifters * Non-AFM/DOD camshaft Michigan Motorsports specifically lists its L86 DOD delete kit for the 2014–2018 L86 and includes the components needed to convert the engine to conventional non-DOD lifters, with a non-DOD camshaft and ECM calibration required as part of the conversion. I was impressed with the overall quality and fitment of the parts. Everything went together well during the rebuild, and I didn’t run into any fitment issues with the Michigan Motorsports components. The GM rod bearings were also the correct later-style 12735504 bearings for my 2017+ L86 application. I took my time putting this engine together because I wanted to make sure everything was right — bearing clearances, fasteners, valvetrain, oiling system, and the DOD conversion. After getting everything assembled, priming the engine, and getting it fired up, the Yukon is running great. The engine has a smooth idle, the valvetrain is quiet, oil pressure looks good, and so far everything is operating exactly how I wanted it to. For me, doing the mechanical DOD delete made a lot of sense while rebuilding the engine. Instead of putting the factory AFM/DOD lifters and associated components back into an engine that was already completely apart, I was able to eliminate that system and convert the valvetrain to a conventional setup. Overall, I’m very happy with the Michigan Motorsports parts and the way this rebuild turned out. The parts fit, the engine went together properly, and most importantly, the Yukon is back on the road and running strong. I’d definitely use Michigan Motorsports again on another LS/LT rebuild and would recommend them to anyone doing an L86 rebuild or DOD delete.
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Bearings
Great quality product.
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Perfect!
Great customer service and as always, Good quality and good price!! Michigan Motorsports is my go-to for my L.S. stuff!
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Bearing install
The bearings look legit.
