Genuine BMW 335i Crankshaft

BMW 335i Crankshaft Parts Questions & Answers

• Engine Crankshaft
  11-21-7-580-483
  Q: What Are the Features of the Crankcase and Crankshaft in an Engine?

  A: The crankcase's upper section has an AluSil insert in a magnesium alloy, with the timing cover part of the engine block. The AluSil cylinder bores lack iron liners, preventing machining, but the deck surface can be planed. The insert has threaded bores for transmission, cylinder head, and crankshaft main bearing bolts, and includes coolant passages. The lower crankcase section is a magnesium bedplate structure with sintered steel inlays for bearing support. A liquid sealant is injected into a groove between crankcase sections. The crankshaft is cast iron with 7 main bearing journals. Connecting rods are cracked for bearing cap centering, have pairing codes, and are weight categorized. Pistons are aluminum with 4 valve reliefs and oil spray jet cooling.
• Crankshaft
  11-21-0-415-080
  Q: What Are the Characteristics of the Engine Block,Crankshaft and Piston?

  A: The N55 engine block is a two-piece unit made of die cast aluminum with cast iron cylinder liners and a separate bedplate. The cylinder liner features a groove between each cylinder bore, allowing coolant to flow from one side of the cooling duct to the other. The engine also features a lightweight crankshaft made of cast iron, which is approximately 3 kg (6.6 lbs) lighter than the crankshaft in the N54 engine and is counterweighted asymmetrically. The N55 engine uses KS pistons with a diameter of 82.5 mm (3.25 in). A plain rectangular ring is used for compression. The second piston ring is a taper-faced Napier ring. The oil scrape ring is a steel band ring with spring, also known as the VF system.