The BMW N45 is a straight-4 DOHC piston engine which replaced the N40 and was produced from 2004-2011. It was produced alongside the N46 and only sold in several countries, where vehicle taxes favoured small displacement engines.

The BMW N45 is a four-cylinder in - line engine from BMW . The N45 engine is a reworked N40 engine . The N45 naturally aspirated engine was offered in the BMW E46 until its use in the 116i . The 316ci and 316ti were used in high-capacity countries where BMW suspected that the 1.8-liter N42 engine would not sell.

The N45 engine, like the N42 engine, has the ME9 engine control, 16 valves and dual VANOS . From the N42 it differs mainly by the missing Valvetronic . The revised version N45N had u. a. a new engine control (like ME1745).

A special position takes the N45B20S with 2 liters of cubic capacity. It was installed in the BMW E90 as 320si. This special model was offered in 2006 as a homologation model for the WTCC in limited edition (2600 pieces).  The engine has some special features. Thus, the liners are made of an aluminum alloy and are joined in the cylinder bore. For regular N45 / N46 engines, these are cast iron and cast into the cylinder block. Further special features are the reinforced connecting rods and the crankcase in bedplate design (aluminum housing with gray cast iron inserts). TheCompaction has been increased from 10.5: 1 to 11: 1. The cast blanks for the cylinder head are produced in the Formula One foundry at BMW's Landshut plant . Because of the high thermal loads during racing, the coolant channels of the cylinder head were designed to be particularly large and used the water cooler of the six-cylinder models. In addition, the N45B20S has specially coated finger followers and single ignition controlled spark plugs . The engine was largely produced by hand at the Hams Hall engine plant . 

The N45 is based on the N46, however it does not have valvetronic variable valve lift. As per the N42 and N46, the N45 has variable valve timing (called VANOS by BMW). In 2007, the N45 was updated, which was called the N45N.

In 2007, the N45's successor - the 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 the N43. The N45 was phased out as new generation vehicles were released with the turbocharged N13.

Models

N45B16

BMW 1 series 2004–2011 E81/E87 116i Engine specification

• 09 / 2003-05 / 2006 in the E46 316Ci Coupé 
• 09 / 2003-05 / 2006 in the E46 316ti Compact 
• 03 / 2004-03 / 2007 in the E87 116i
• 03 / 2005-03 / 2007 in the E90 316i 
• 1.6 liters (1596 cc).

• 85 kW (116 hp), 150 Nm

Applications:

• 2004–2011 E81/E87 116i
• 2006–2011 E90/E91 316i
• 1.6 liters (1596 cc).
• 85 kW (116 hp), 150 Nm

N45B20S

The N45 was enlarged to 2.0 litres, to homologate the E90 320si for the World Touring Car Championship. The N45 was chosen over the N46, because its lack of variable valve timing allows higher engine speeds.

Applications:

• 2006 E90 320si (Limited production model)
• 2.0 liters (1997 cc).
• 126 kW (173 hp), 200 Nm

The BMW N43 is a straight-4 naturally aspirated gasoline engine DOHC engine which was sold from 2007-2011. It replaced the N46 (and related N45), however the N43 was not sold in countries with high sulfur fuel, therefore the N45/N46 engines remained in production alongside the N43.

The BMW N43 with four cylinders in a row . The light alloy engine has two overhead camshafts and 16 valves. He has a spray- guided gasoline direct injection , which operates in the partial load range in lean operation. So could the 116i compared to the previous engine N45 a performance increase of six percent while reducing fuel consumption by 23% can be achieved. Since low-sulfur gasoline for the lean operation is needed, the N43 in many markets could not be offered. In these markets, the predecessor engines were therefore N45 and N46 available in modified form.

The N46B20 is identical to the N43B20 in many parts, such. B. the crankshaft or the oil pan. As of 2011, the N43 was the N13 replaced. 
The N43 replaced the technically similar, but without direct injection operating BMW N42 engine, which was used from 2001 to 2004. In addition, the N43 was equipped with start-stop system and brake energy recovery (see also BMW EfficientDynamics ). 

Compared with its N46 predecessor, the N43 features direct injection.

In 2011, as part of BMW's shift to turbocharging, the N43 was replaced by the turbocharged N13.

Engine Models

N43B16

The N43B16 has a 1,599 cc (98 cu in) displacement and produces 90 kW (121 hp) and 160 N·m (118 lb·ft). It is the successor to the N45 engine and, as per the N45, does not have valvetronic.

Applications:

• 2007-2009 E87 116i
• 2008 E90 316i

N43B20

The N43B20 has a 1995 cc displacement and produces up to 127 kW (173 PS; 170 hp) and 210 Nm.

In 2009, the 2.0 litre N43B20 replaced the 1.6 litre N43B16 in the 116i. Power remained at 90 kW (121 hp), however torque was increased. It is suggested that this 90 kW version might not have valvetronic.

Applications:

90 kW (121 hp) and 185 N·m (136 lb·ft) version

• 2009-2011 E81/E87 116i

110 kW (148 hp) and 190 N·m (140 lb·ft) version

• 2007-2011 E90/E91/E92/E93 318i
• 2008-2011 E81/E87/E88 118i

127 kW (170 hp) and 210 N·m (155 lb·ft) version

• 2007-2011 E81/E82/E87/E88 120i
• 2007-2011 E90/E91/E92/E93 320i
• 2007-2009 E60/E61 520i
• since 03/2007 E81 / E87 as 120i
• since 09/2009 E82 as a 120i Coupe 
• since 03/2008 E88 as 120i Cabriolet 
• since 09/2007 E90 / E91 as 320i
• since 09/2007 E92 320i Coupe
• since 09/2007 E93 320i Convertible
• since 03/2007 E60 as 520i

The BMW N42 is a straight-4 DOHC piston engine which replaced the M43 and was produced from 2001-2004.

Compared with its M43 predecessor, the N42 features a DOHC valvetrain and variable valve timing (called VANOS by BMW). It was the first BMW engine to feature variable valve lift (called valvetronic by BMW). The N42 serves as the basis for the smaller N40 engine (which does not have valvetronic).BMW -developed petrol engine with four cylinders and 16 valves, two overhead camshafts are operated. 

The N42 is the first engine model to use the Valvetronic system , resulting in lower fuel consumption, lower exhaust emissions, better responsiveness, and smoother operation. It also has double VANOS , two gear-driven balancing shafts, and in the case of variant N42B20, the two-stage variable intake manifold DISA. Aluminum was used for the crankcase (engine block) and the cylinder head. As engine controlserved the Bosch DME ME9.2 EK924. 

In 2001, the N42 won the International Engine of the Year Award . 

The engine was used in the 3 Series (E46) in two variants, as 316i with 1796 cc and 115 hp and as 318i with 1995 cc and 143 hp. At the same time, the BMW N40 with reduced displacement without Valvetronic was developed for certain world markets .

The BMW N42 was replaced by the BMW N45 / N46 .

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

In 2004, the N42 was replaced by the N46 engine.

Models

N42B18

Applications:

2001-2004 BMW 3 series E46 316i and 316ti

The N42B18 has a displacement of 1796 cc, uses Bosch DME ME9.2 fuel injection and has twin-balancing shafts
N42B20

Applications:

• 2001-2004 BMW 3 series E46 318i/318Ci/318ti

The N42B20 has a displacement of 1995 cc, uses Bosch DME ME9.2 fuel injection and has twin-balancing shafts.

The BMW N40 is an straight-4 DOHC engine which replaced the 1.6 litre versions of the 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.

The N40 is a four-cylinder naturally aspirated engine from the car manufacturer BMW with 16 valves. This replaced the BMW M43 . The BMW N40 was developed specifically for sales markets with special displacement control and in parallel with the N42 . So z. For example, the cylinder-crankcase together with the piston of these motors identical,  as the cylinder bore of 84 mm is the same. The different displacements are generated by another stroke. Unlike the N42 , the N40 does not have the Valvetronic system.

Design

The N40 is based on the N42 and uses the same crankcase, pistons and bore size of 84 mm (3.3 in).

The differences compared with the N42 include a 9 mm (0.4 in) reduction in stroke length (which results in the smaller displacement) and the N40 does not have Valvetronic.

Models

Applications:

• 2001-2005 E46 316i/316ci/316ti (certain markets only)
• 07 / 2003-02 / 2004 in the BMW E46 as a 316ci Coupe 
• 07 / 2003-02 / 2004 in BMW E46 as 316ti Compact 
• 07 / 2003-02 / 2004 in the BMW E46 as 316i