{{Infobox automobile engine |name=BMW N42 engine |production=2001–2004 |configuration =Inline-4 |head =Aluminium |block =Aluminium |valvetrain =DOHC, with VVT & VVL |fueltype=Petrol |displacement={{ubl | {{cvt|1796|cc|L|1}} | {{cvt|1995|cc|L|1}} }} | bore = {{convert|84|mm|in|2|abbr=on}} | stroke = {{ubl | {{convert|81|mm|in|2|abbr=on}} | {{convert|90|mm|in|2|abbr=on}} }} |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.<ref name="bmwhaven">{{cite web|url=http://www.bmwheaven.com/database/engine.php?type=N42 |title=Engine specifications for N42 engines |website=www.bmwheaven.com |date= |accessdate=2012-06-03}}</ref><ref>{{cite web|title=3'E46 318ci model selection|url=http://www.realoem.com/bmw/enUS/select?product=P&archive=0&series=E46&body=Cab&model=318Ci&market=EUR&prod=20040200|website=www.realoem.com|accessdate=16 March 2017}}</ref>
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.<ref>{{cite web|title=Archive|url=http://www.ukimediaevents.com/engineoftheyear/archive.php|website=www.ukimediaevents.com|accessdate=22 March 2017}}</ref>
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.<ref>{{cite web|title=BMW N42B20 Engine|url=https://mywikimotors.com/n42b20/|website=www.mywikimotors.com|accessdate=1 October 2017|archive-url=https://web.archive.org/web/20171002232346/http://mywikimotors.com/n42b20/|archive-date=2 October 2017|url-status=dead}}</ref> It was the first BMW engine to have Valvetronic (variable valve lift).<ref>{{cite web|title=BMW N42 Four Cylinder Valvetronic Engine|url=http://www.unixnerd.demon.co.uk/n42.html|website=www.unixnerd.demon.co.uk|accessdate=22 March 2017|archive-date=7 February 2020|archive-url=https://web.archive.org/web/20200207170317/http://www.unixnerd.demon.co.uk/n42.html|url-status=dead}}</ref><ref>{{cite web|url=http://bmwfans.info/parts/catalog/E46/Coupe/Europe/318Ci-N42/browse/engine/valve_timing_gear_cntrl_unit_valvetronic/ |title=Valve timing gear, cntrl unit Valvetronic BMW 3' E46, 318Ci (N42) — BMW parts catalog |website=www.bmwfans.info |date= |accessdate=3 June 2012}}</ref>
== Versions == {| class=wikitable |- ! Version !!Displacement!!Power!!Torque!!Year |- |N42B18||{{cvt|1796|cc|L|1|disp=flip}}|| {{cvt|85|kW|PS bhp|0}} <br/> at 5,500 rpm|| {{cvt|175|Nm|lbft|0}} <br/> at 3,750 rpm||2001-2004 |- |N42B20||{{cvt|1995|cc|L|1|disp=flip}}|| {{cvt|105|kW|PS bhp|0}} <br/> at 6,000 rpm|| {{cvt|200|Nm|lbft|0}} <br/> at 3,750 rpm||2001-2004 |}
==N42B18== The N42B18 has a displacement of {{convert|1796|cc|cuin|1|abbr=on}},<ref name="bmwhaven" /> uses Bosch Motronic ME9.2 engine management<ref>{{cite web|title=BMW 3 2006 / E46|url=http://obdtester.com/bimcom-eculist/bmw/3/2006_e46|website=www.obdtester.com|accessdate=22 March 2017}}</ref> and {{citation needed span|text=has twin-balancing shafts.|date=June 2012}}
Applications: * 2001-2004 E46 316i and 316ti
==N42B20== The N42B20 has a displacement of {{cvt|1995|cc|cuin|1}},<ref name="bmwhaven" /> {{citation needed span|text=uses Bosch DME ME9.2 fuel injection and has twin-balancing shafts.|date=June 2012}} The N42B20 redlines at 6,600 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 engine speeds. *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
== {{Anchor|BMW N40}}N40 == {{Infobox automobile engine | name = BMW N40 engine | production = 2001–2004 | configuration = Inline-4 | displacement = {{cvt|1596|cc|L|1|order=flip}} | bore = {{cvt|84|mm|in|2}} | stroke = {{cvt|72|mm|in|2}} | block = Aluminium | head = Aluminium | valvetrain = DOHC, with VVT | fueltype = Petrol | predecessor = BMW M43 | successor = BMW N45 }}The '''BMW N40''' is a DOHC four-cylinder petrol engine which replaced the 1.6 litre versions of the BMW M43.<ref>{{cite book |last=Lewin |first=Tony |title=The Complete Book of BMW: Every Model in the World Since 1962 |publisher=MotorBooks International |year=2004 |isbn=9781610592055 |pages=258–259}}</ref> 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 === right|thumb|BMW E46/5 316ti The N40 is based on the BMW N42 engine and uses the same crankcase, pistons and bore size of {{convert|84|mm|in|1|abbr=on}}. The redline is 6,500 rpm.
Unlike the N42, the N40 does not have Valvetronic (variable valve lift). The other major difference is a {{convert|9|mm|in|1|abbr=on}} reduction in stroke to {{convert|72.0|mm|in|1|abbr=on}}, which results in a smaller displacement than the N42.
=== Versions === {| class="wikitable" style="text-align: center;" !Version !Displacement !Power !Torque !Years |- |'''N40B16''' |{{cvt|1596|cc|L|0|disp=flip}} |{{cvt|85|kW|PS bhp|0}}<br>at 6,100 rpm |{{cvt|150|Nm|lbft|0}}<br>at 4,300 rpm |2001–2004 |} Applications:<ref>{{cite web |title=3'E46 316i model selection |url=http://www.realoem.com/bmw/enUS/select?product=P&archive=0&series=E46&body=Lim&model=316i&market=EUR&prod=20010600 |accessdate=12 March 2017 |website=www.realoem.com}}</ref>
* 2001-2005 E46 316i/316ci/316ti (certain markets only)
==See also== * BMW * List of BMW engines
==References== {{reflist|30em}}
{{BMW automotive petrol engines: 2000s to 2010s}}
N42 Category:Straight-four engines Category:Gasoline engines by model