{"product_id":"acl-trimetal-reinforced-main-bearings-renault-f1-f2-f3-f4-f7","title":"ACL Race Series main bearings for Renault F1, F2, F3, F4, F7","description":"\u003cp\u003eACL Race Series main bearing set for Renault F1, F2, F3, F4, F7, part number 5M7807H. These are the bearings that support the crankshaft in the block and, in a tuned engine, they are responsible for ensuring oil effectively reaches the entire crankshaft.\u003c\/p\u003e\u003cp\u003eInternally, they feature three layers on a high-strength steel backing: a copper-lead-tin lining, a thin nickel barrier, and a lead-tin-copper sliding layer, which is the surface that works against the crankshaft.\u003c\/p\u003e\u003cp\u003eThe upper shells have a full 180° oil groove, while the lower shells have a partial groove to ensure oil flow to the connecting rods is not interrupted, with a tapered groove end to prevent pressure spikes. ACL manufactures them with more \"crush\" (housing interference) than a standard bearing for a tighter fit and better heat dissipation, as well as greater eccentricity, which helps maintain the oil film when the housing deforms at high RPMs.\u003c\/p\u003e\u003cp\u003eIn standard size, ACL specifies this for a crankshaft journal diameter of 54.785 to 54.795 mm, and recommends an oil clearance of approximately 0.057 to 0.068 mm for that diameter. If the crankshaft has been reground, the required size changes.\u003c\/p\u003e\u003cp\u003eThese bearings do not have the silver-tin final coating found on standard bearings, so their dark, brownish-black-bluish color is the factory finish and does not indicate a defect. ACL advises against polishing the bearing surface to adjust clearance; if more is needed, combine them with the HX version, which provides 0.025 mm of extra clearance.\u003c\/p\u003e\u003cp\u003eIf the crankshaft has been reground or you are unsure which size you need, please write to us with your engine code before ordering.\u003c\/p\u003e","brand":"ACL","offers":[{"title":"Default Title","offer_id":50813111402830,"sku":"ACL-5M7807H\/111","price":75.42,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0816\/7329\/0062\/files\/acl-main-bearings_dece54dc-4d8c-44c3-87be-611fe846abe5.jpg?v=1735903874","url":"https:\/\/driftandgrip.com\/en\/products\/acl-trimetal-reinforced-main-bearings-renault-f1-f2-f3-f4-f7","provider":"Drift \u0026 Grip","version":"1.0","type":"link"}