BMW N42

BMW N40 engine
BMW N40 engine
Overview
Production	2001–2004
Layout
Configuration	Inline-4
Displacement	1.6 L (1,596 cc)
Cylinder bore	84 mm (3.31 in)
Piston stroke	72 mm (2.83 in)
Cylinder block material	Aluminium
Cylinder head material	Aluminium
Valvetrain	DOHC, with VVT
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW M43
Successor	BMW N45

BMW N42 engine
BMW N42 engine
Overview
Production	2001–2004
Layout
Configuration	Inline-4
Displacement	1,796 cc (1.8 L); 1,995 cc (2.0 L);
Cylinder bore	84 mm (3.31 in)
Piston stroke	81 mm (3.19 in); 90 mm (3.54 in);
Cylinder block material	Aluminium
Cylinder head material	Aluminium
Valvetrain	DOHC, with VVT & VVL
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW M43
Successor	BMW N46

The BMW N42 is a DOHC four-cylinder petrol engine which replaced the BMW M43 and was produced from 2001-2004.

The N42 serves as the basis for the smaller N40 engine (which does not have Valvetronic).

The N42B18 won the 1.4-1.8 L category of the International Engine of the Year awards for 2001.

In 2004, the N42 was replaced by the BMW N46 four-cylinder engine.

Design

Compared with its M43 predecessor, the N42 features a DOHC valvetrain, VANOS (variable valve timing) and an aluminium engine block. It was the first BMW engine to have Valvetronic (variable valve lift).

Versions

Version	Displacement	Power	Torque	Year
N42B18	1,796 cc (109.6 cu in)	85 kW (114 bhp) at 5,500 rpm	175 N⋅m (129 lb⋅ft) at 3,750 rpm	2001-2004
N42B20	1,995 cc (121.7 cu in)	105 kW (141 bhp) at 6,000 rpm	200 N⋅m (148 lb⋅ft) at 3,750 rpm	2001-2004

N42B18

The N42B18 has a displacement of 1,796 cc (109.6 cu in), uses Bosch Motronic ME9.2 engine management and has twin-balancing shafts.

Applications:

2001-2004 E46 316i and 316ti

N42B20

The N42B20 has a displacement of 1,995 cc (121.7 cu in), uses Bosch DME ME9.2 fuel injection and has twin-balancing shafts.
The N42B20 revs to 6600 rpm

Applications:

2001-2004 E46 318i/318Ci/318ti

N40

The BMW N40 is a DOHC four-cylinder petrol engine which replaced the 1.6 litre versions of the BMW M43. It was produced from 2001-2004 and only sold in several countries, where taxes favoured cars with smaller displacement engines. The N40 was replaced by the BMW N45.

Design

BMW E46/5 316ti

The N40 is based on the BMW N42 engine and uses the same crankcase, pistons and bore size of 84 mm (3.3 in). The redline is 6,500 rpm.

Unlike the N42, the N40 does not have Valvetronic (variable valve lift). The other major difference is a 9 mm (0.4 in) reduction in stroke to 72.0 mm (2.8 in), which results in a smaller displacement than the N42.