{"product_id":"acl-trimetal-reinforced-main-bearings-mitsubishi-lancer-evo-6-to-9-4g63-4g64-97","title":"ACL Race Series main bearings for Mitsubishi Lancer Evo 6 to 9 (4G63, 4G64 - 97+)","description":"\u003cp\u003eACL Race Series main bearings for Mitsubishi Lancer Evo 6 to 9 (4G63, 4G64 - 97+), part number 5M1219H. These support the crankshaft in the block, and in a tuned engine, they are responsible for ensuring that oil reaches the entire crankshaft properly.\u003c\/p\u003e\u003cp\u003eThese are tri-metal bearings: SAE 1010 steel base, a copper, lead, and tin layer of approximately 0.3 mm, a nickel barrier, and a surface layer of lead, tin, and copper that conforms to the crankshaft surface and resists seizing.\u003c\/p\u003e\u003cp\u003eThe upper bearings feature a full 180° oil groove, while the lower ones have a partial groove to maintain oil flow to the connecting rods, with a tapered groove end to prevent pressure spikes. Compared to stock bearings, the Race series has more crush for better seating and heat transfer, and increased eccentricity to promote an oil film at high engine speeds.\u003c\/p\u003e\u003cp\u003eIn standard size, ACL specifies them for a crankshaft journal diameter of 56.985 to 57.000 mm, recommending an oil clearance of approximately 0.059 to 0.070 mm for that diameter. If the crankshaft has been ground, the measurements will change.\u003c\/p\u003e\u003cp\u003eThey do not have the silver tin finish of standard bearings, so their dark color—ranging between brown, black, and bluish—is the factory appearance and does not indicate any defect. ACL advises against polishing the bearing surface to adjust clearance; if more is needed, they should be combined 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":50813086826830,"sku":"ACL-5M1219H-STD","price":86.5,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0816\/7329\/0062\/files\/acl-main-bearings_f1db7c5b-ffca-475f-9478-a519cd73a250.jpg?v=1735903768","url":"https:\/\/driftandgrip.com\/en\/products\/acl-trimetal-reinforced-main-bearings-mitsubishi-lancer-evo-6-to-9-4g63-4g64-97","provider":"Drift \u0026 Grip","version":"1.0","type":"link"}