BMW N52

BMW N52 engine
Overview
Manufacturer	BMW, Bayerische Motoren Werke AG
Production	2004–2015
Combustion chamber
Configuration	Straight-6
Chronology
Predecessor	BMW M54
Successor	BMW N53 (except North America, Australia and Malaysia), BMW N20 (North America, Australia and Malaysia)

The BMW N52 is a straight-6 DOHC piston engine which was produced from 2004-2015. It debuted on the E90 330i and E63 630i. In European markets, it began to be phased out following the release of the N53 in 2007. However, in markets such as North America, Australia or Malaysia, the N53 was deemed unsuitable due to the high levels of sulfur in the fuel. Therefore, the N52 remained in production until its replacement by the N20 turbocharged 4-cylinder engine in 2015.

Compared with its M54 predecessor, the N52 features variable valve lift (called Valvetronic by BMW), a lighter block due to the use of a magnesium alloy and an electric water pump and a variable oil pump. Like the M54, the N52 uses an electronic throttle control, variable valve timing to both camshafts (called dual VANOS by BMW) and a infinitely variable length intake manifold (called "DISA" by BMW). Later BMW changed the technology to a dual intake technology for later car models but kept the name DISA.

The N52 engine block is cast with magnesium and aluminum for the crankcase. Magnesium is used to save weight. However, magnesium is subject to a greater risk of corrosion from water, and magnesium may tend to creep under load at high temperatures. Thus, magnesium in its pure form or as a conventional alloy is not suited for permanently conveying high loads and forces of the kind typically encountered in central components of the engine. Therefore, BMW combined the N52 block to use magnesium alloy for the crankcase shell, with an aluminum “inner block” to complement the magnesium disadvantages.

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Wikipedia