{"product_id":"michigan-motorsports-ls-main-crank-bearings-standard-size-si-series-complete-5-bearing-kit-bi-metal-construction","title":"Michigan Motorsports LS Main Crank Bearings Standard Size SI-Series — Complete 5-Bearing Kit, Bi-Metal Construction","description":"\u003cb\u003eMichigan Motorsports SI-Series standard-size main crank bearings are a complete five-bearing kit engineered to fit Gen III and Gen IV LS V8 engines using factory crankshafts.\u003c\/b\u003e\n\n\u003cp\u003eRefresh or upgrade the bottom end of an LS engine with a purpose-built bearing set designed for reliability and predictable oil clearance. This SI-Series kit was created for the common 4.8L, 5.3L, 5.7L, 6.0L and 6.2L LS platforms and includes all five main bearings required for a full installation. The bearings use a bi-metal silicon-aluminum construction that balances load support with durable wear resistance, making them suitable for stock rebuilds, street performance upgrades, and LS swap projects where the factory crankshaft is retained.\u003c\/p\u003e\n\n\u003ch3\u003eWill these bearings fit my Gen III\/Gen IV LS engine?\u003c\/h3\u003e\n\u003cp\u003eYes — the set is intended for standard-size mains on most LS family engines that use original crankshaft journal diameters. It covers a wide list of popular engine codes across cars, trucks, and SUVs.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eCompatible with LS1, LS2, LS3, LS6 and many truck-based blocks\u003c\/li\u003e\n  \u003cli\u003eFits LQ4, LQ9, L92, L94, L76, L77, LY6, L96 and similar castings\u003c\/li\u003e\n  \u003cli\u003eSupplied as a full five-bearing set for complete rebuilds\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does the SI-Series design help engine longevity?\u003c\/h3\u003e\n\u003cp\u003eThe bearing construction combines a supporting steel-backed layer with a silicon-aluminum alloy running surface to resist wear while maintaining necessary conformability. That combination helps the bearing accommodate small surface irregularities on nodular iron crank journals and preserves oil film integrity under load.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBi-metal construction improves load capacity and wear resistance\u003c\/li\u003e\n  \u003cli\u003eMaintains proper oil clearance to protect journal surfaces\u003c\/li\u003e\n  \u003cli\u003eHelps smooth microscopic crankshaft imperfections for quieter operation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre these bearings suitable for performance builds or only stock rebuilds?\u003c\/h3\u003e\n\u003cp\u003eThey are engineered to serve both stock rebuilds and many street-performance applications that retain an OEM crankshaft. The SI-Series focuses on delivering predictable clearance, durability, and consistent behavior under typical operating conditions rather than extreme racing stress.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eIdeal for stock refreshes, everyday drivers, and mild performance upgrades\u003c\/li\u003e\n  \u003cli\u003eWorks with factory crankshafts—no custom machining required for standard-size journals\u003c\/li\u003e\n  \u003cli\u003eNot intended for high-horsepower engines requiring specialty oversized or coated bearings\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat comes in the package and what should I check during installation?\u003c\/h3\u003e\n\u003cp\u003eThe kit includes five standard-size main bearings to outfit the crankshaft main journals. During installation, verify journal diameter, measure oil clearances with plastigauge or micrometers, and follow torque specs and lubrication procedures for break-in.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eComplete five-bearing set for full main cap coverage\u003c\/li\u003e\n  \u003cli\u003eConfirm crank journal size and bearing orientation before final assembly\u003c\/li\u003e\n  \u003cli\u003eUse proper assembly lube and check clearances to OEM tolerances\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: This bearing set is aimed at mechanics, hobbyists, and engine builders refreshing Gen III\/IV LS engines who plan to retain the factory crankshaft. It fits restorations, street-driven performance rebuilds, and common LS swap projects where dependable, standard-size main bearings are required. If you need oversized, coated, or race-specific bearings, choose a specialized product; for reliable OEM-dimension rebuilds and many performance applications, this Michigan Motorsports SI-Series set is a practical choice.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Do these bearings fit an LS3 crankshaft?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. These are standard-size mains compatible with LS3 engines that use factory crankshaft journal dimensions.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this set for a high-horsepower build?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: This SI-Series set suits stock and many street-performance builds; for extreme power levels choose oversized or race-spec bearings.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Michigan Motorsports","offers":[{"title":"Default Title","offer_id":48083873235102,"sku":"B099KNX6Z3","price":94.98,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/michigan-motorsports-front-package.jpg?v=1785837902","url":"https:\/\/northtrailauto.ca\/products\/michigan-motorsports-ls-main-crank-bearings-standard-size-si-series-complete-5-bearing-kit-bi-metal-construction","provider":"North Trail Auto","version":"1.0","type":"link"}