{"product_id":"acl-trimetal-reinforced-main-bearings-suzuki-hayabusa-1299cc","title":"ACL Race Series main bearings for Suzuki Hayabusa 1299cc","description":"\u003cp\u003eACL Race Series main bearings for Suzuki Hayabusa 1299cc, part number 5M8434H. These support the crankshaft in the block, and in a performance engine, they are responsible for ensuring oil reaches the entire crankshaft properly.\u003c\/p\u003e\u003cp\u003eThe structure is tri-metal, featuring a steel base, a copper-lead-tin lining, a nickel barrier, and a soft surface layer that conforms and prevents seizure even under very high loads.\u003c\/p\u003e\u003cp\u003eThe upper shells have a full 180° oil groove, while the lower shells have a partial groove to avoid restricting oil flow to the connecting rods, with a tapered groove end to prevent pressure spikes. Race Series bearings have increased crush and a slightly more eccentric shape than standard bearings—two details designed to ensure the bearing remains seated and properly lubricated even when the block and rods deform under load.\u003c\/p\u003e\u003cp\u003eIn standard size, ACL specifies them for a crankshaft main journal diameter of 39.976 to 40.000 mm, recommending an oil clearance of approximately 0.045 to 0.053 mm for this diameter. If the crankshaft has been reground, the measurement changes.\u003c\/p\u003e\u003cp\u003eThey do not have the silver-tin finish of standard bearings, so their dark color—ranging from brown and black to bluish—is the factory finish and does not indicate any defect. ACL advises against polishing the bearing surface to adjust clearance; if more clearance is needed, combine them with the HX version, which provides an additional 0.025 mm of clearance.\u003c\/p\u003e\u003cp\u003eNot sure if your crankshaft is standard size? Write to us with your engine code and we will help you choose.\u003c\/p\u003e","brand":"ACL","offers":[{"title":"Default Title","offer_id":50813137748302,"sku":"5M8434H-STD","price":163.04,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0816\/7329\/0062\/files\/d3414404389cda38ce7ea0238d8c23b3.jpg?v=1735904075","url":"https:\/\/driftandgrip.com\/en\/products\/acl-trimetal-reinforced-main-bearings-suzuki-hayabusa-1299cc","provider":"Drift \u0026 Grip","version":"1.0","type":"link"}