{"product_id":"acl-trimetal-reinforced-rod-bearings-bmw-s14-7-motorsport","title":"ACL Race Series connecting rod bearings for BMW S14\/7 Motorsport","description":"\u003cp\u003eACL Race Series connecting rod bearing set for BMW S14\/7 Motorsport, part number 4B1489H. This is ACL’s competition range, the same used in drift, circuit, and drag racing engines.\u003c\/p\u003e\u003cp\u003eThe structure is tri-metal, with a steel backing, a copper-lead-tin lining, a nickel barrier, and a soft overlay that conforms and prevents seizure even under very high loads. On the connecting rod bearings, the overlay is thinner to better withstand fatigue.\u003c\/p\u003e\u003cp\u003eCompared to a stock bearing, the Race range features higher crush for better seating and heat transfer, and increased eccentricity to promote an oil film when the engine is running at high RPM.\u003c\/p\u003e\u003cp\u003eIn standard size, ACL specifies this for a rod journal of 44.975 to 44.991 mm, with a bearing width of 16.0 mm. For that diameter, they recommend an oil clearance of about 0.049 to 0.058 mm, measured with a micrometer and bore gauge. If the crankshaft has been ground, the measurement changes.\u003c\/p\u003e\u003cp\u003eThey do not have the silver-tin final plating of standard bearings, so their dark, brownish-black-bluish color is as manufactured and does not indicate any defect. ACL advises against polishing the bearing surface to adjust clearance; if more 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":50813077881166,"sku":"ACL-4B1489H\/14","price":125.33,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0816\/7329\/0062\/files\/acl-rod-bearings_eda3d213-86c5-4596-939e-5d6aab22cf0b.jpg?v=1735903624","url":"https:\/\/driftandgrip.com\/en\/products\/acl-trimetal-reinforced-rod-bearings-bmw-s14-7-motorsport","provider":"Drift \u0026 Grip","version":"1.0","type":"link"}