The BMW N45 is a naturally aspirated four-cylinder petrol engine which replaced the BMW N40 and was produced from 2004-2011. It was produced alongside the BMW N46 engine and only sold in some countries, where vehicle taxes favoured small-displacement engines.
5-688: The N45 is based on the N46, however it does not have balance shafts or Valvetronic (variable valve lift). As per the N42 and N46, the N45 has double-VANOS (variable valve timing). In 2007, the N45 was updated, which was called the N45N. In 2007, the N45's successor - the BMW N43 - was introduced. However, the direct-injected N43 was not sold in countries with high-sulfur fuel, so the N45 continued to be produced alongside
10-448: A range of 225 degrees to push the intermediate arm towards, or away from, the camshaft. For lesser lift, the eccentric shaft moves the intermediate arm away from the camshaft, so that lesser of the camshaft profile is pressing on the intermediate arm. For more lift, the intermediate arm is moved closer to the camshaft, which increases the camshaft profile acting on the intermediate arm. First-generation Valvetronic systems can decrease
15-459: A traditional engine where the camshaft acts onto a rocker arm that actuates the valves , an engine with Valvetronic has an intermediate arm between the rocker and the camshaft, which allows the valve lift to be varied depending on the position of an eccentric shaft adjacent to the intermediate arm. The eccentric shaft, whose position is controlled by the DME using an electric motor, rotates through
20-488: Is the carbon fiber valve cover. Applications: Valvetronic The Valvetronic system is a BMW variable valve lift system which, in combination with VANOS , allows infinite adjustment of the intake valve timing and lift. The system claims to improve fuel economy and emissions, and negates the need for a throttle body in regular use. First introduced by BMW on the 316ti compact in 2001, Valvetronic has since been added to many of BMW's engines. Unlike
25-658: The N43. The N45 was phased out as new generation vehicles were released with the turbocharged BMW N13 four-cylinder engine. Applications: The N45 was enlarged to 1,997 cc (121.9 cu in), to homologate the E90 320si for the World Touring Car Championship . The N45 was chosen over the N46, because its lack of variable valve lift allows higher engine speeds. Instead, the engine used dual overhead camshafts and 16 valves. The main visual difference
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