Top Qs
Timeline
Chat
Perspective
BMW N42
Reciprocating internal combustion engine From Wikipedia, the free encyclopedia
Remove ads
The BMW N42 is a DOHC four-cylinder petrol engine which replaced the BMW M43 and was produced from 2001-2004.[1][2]
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.[3]
In 2004, the N42 was replaced by the BMW N46 four-cylinder engine.
Remove ads
Design
Compared with its M43 predecessor, the N42 features a DOHC valvetrain, VANOS (variable valve timing) and an aluminium engine block.[4] It was the first BMW engine to have Valvetronic (variable valve lift).[5][6]
Versions
N42B18
The N42B18 has a displacement of 1,796 cc (109.6 cu in),[1] uses Bosch Motronic ME9.2 engine management[7] and has twin-balancing shafts.[citation needed]
Applications:
- 2001-2004 E46 316i and 316ti
N42B20
The N42B20 has a displacement of 1,995 cc (121.7 cu in),[1] uses Bosch DME ME9.2 fuel injection and has twin-balancing shafts.[citation needed] The N42B20 revs to 6600 rpm
The N42B20 replaced older engines like the M43TU and M44B19, and was succeeded by the N46 and N45 series.
Key Technologies Double VANOS: Adjusts both intake and exhaust camshaft timing for better torque and efficiency across RPMs.
Valvetronic: BMW’s variable valve lift system, which eliminates the need for a traditional throttle body and improves fuel economy.
DISA Manifold: A variable-length intake system that optimizes airflow for low-end torque and high-end power.
Aluminum Block: Lighter than its cast-iron predecessors, improving weight distribution and fuel economy.
Applications:
- 2001-2004 E46 318i/318Ci/318ti
Remove ads
N40
Summarize
Perspective
The BMW N40 is a DOHC four-cylinder petrol engine which replaced the 1.6 litre versions of the BMW M43.[8] 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

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.
Versions
Applications:[9]
- 2001-2005 E46 316i/316ci/316ti (certain markets only)
Remove ads
See also
References
Wikiwand - on
Seamless Wikipedia browsing. On steroids.
Remove ads