| BMW N74 engine | |
|---|---|
 Model of an N74 | |
| Overview | |
| Production | 2009–present |
| Layout | |
| Configuration | 60° V12 |
| Displacement | 6.0 L (5,972 cc) (2009–2015) 6.6 L (6,592 cc) (2009–2022) 6.7 L (6,749 cc) |
| Cylinder bore | 89 mm (3.50 in) |
| Piston stroke | 80 mm (3.15 in) 88.3 mm (3.48 in) 90.4 mm (3.56 in) |
| Cylinder block material | Aluminium |
| Cylinder head material | Aluminium |
| Valvetrain | DOHC with VVT |
| Combustion | |
| Turbocharger | Twin-turbo |
| Fuel type | Petrol |
| Output | |
| Power output | 400–465 kW (536–624 hp) |
| Torque output | 750–900 N⋅m (553–664 lb⋅ft) |
| Chronology | |
| Predecessor | BMW N73 |
The BMW N74 is a twin-turbo V12 petrol engine which replaced the N73 and has been produced since 2008. It is BMW's first turbocharged V12 engine and is also used in several Rolls-Royce models.
Design
[edit]The N74 features twin turbochargers, which are not present on its naturally aspirated BMW N73 predecessor. The turbochargers are located on the outside of the engine and use a boost pressure of 11.6 psi (0.8 bar).[1] In its base configuration the engine has a compression ratio of 10:1 and a specific fuel consumption of 245 g·kW−1·h−1.[2]
Like its predecessor, the N74 has direct injection, DOHC and variable valve timing (called double-VANOS by BMW).[3][4] However, the N74 does not have variable valve lift (called Valvetronic by BMW).[5]
The N74 marked BMW's first use of an 8-speed automatic transmission, in the form of the ZF 8HP90.[1]
Versions
[edit]| Engine | Displacement | Power | Torque | Year |
|---|---|---|---|---|
| N74B60[2] | 5,972 cc (364.4 cu in) | 400 kW (536 hp) at 5,250 rpm |
750 N⋅m (553 lb⋅ft) at 1,500–5,000 rpm |
2008–2015 |
| N74B66 | 6,592 cc (402.3 cu in) | 420 kW (563 hp) at 5,250 rpm |
780 N⋅m (575 lb⋅ft) at 1,500–5,000 rpm |
2009–2020 |
| 465 kW (624 hp) at 5,600 rpm |
800 N⋅m (590 lb⋅ft) at 1,500–5,500 rpm |
2013–2022 | ||
| 442 kW (593 hp) at 5,250 rpm |
840 N⋅m (620 lb⋅ft) at 1,500 rpm |
2016–2020 | ||
| N74B66TU | 449 kW (602 hp) at 5,500 rpm |
800 N⋅m (590 lb⋅ft) at 1,500 rpm |
2016–2019 | |
| 447.5 kW (600 hp) at 5,500 rpm |
850 N⋅m (627 lb⋅ft) at 1,550 rpm |
2020–2022 | ||
| N74B68 | 6,750 cc (411.9 cu in) | 420 kW (563 hp) at 5,250 rpm |
900 N⋅m (664 lb⋅ft) at 1,500 rpm |
2017–present |
N74B60
[edit]This initial version of the N74 has a bore of 89 mm (3.5 in) and a stroke of 80 mm (3.1 in). The redline is 7000 rpm and the compression ratio is 10.0:1.[6]
Applications:
- 2009–2015 F01/F02/F03 760i/760Li[7]
N74B66
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The N74B66 is an enlarged version of the N74B60, due to a stroke of 88 mm (3.5 in). The redline is 7000 rpm and the compression ratio is 10.0:1. It produces up to 465 kW (624 hp) and is used in the Rolls-Royce Ghost.[1]
| Year | Application | Power output | Torque |
|---|---|---|---|
| 2010–2020 | Rolls-Royce Ghost | 420 kW (563 hp) | 780 N⋅m (575 lb⋅ft) |
| 2014–2020 | Rolls-Royce Ghost V-Specification | 442 kW (593 hp) | 780 N⋅m (575 lb⋅ft) |
| 2019 | Eadon Green Panthean Coupe[3] | 840 N⋅m (619.5 lb⋅ft) | |
| 2014– | Rolls-Royce Wraith | 465 kW (624 hp) | 800 N⋅m (590 lb⋅ft) |
| 2015– | Rolls-Royce Dawn | 420 kW (563 hp) | 820 N⋅m (605 lb⋅ft) |
N74B66TU
[edit]2016 saw the introduction of the 6.6 liter N74 V12 variant to the BMW 7-series along with some Technical Updates (TU) for reliability. The facelifted 2020 models saw power reduced in the EU market to 430kW (577 bhp) due to emission regulations. This was partially compensated with an increase in torque to 850Nm (627 lb-ft). US models enjoyed the bump in torque with horsepower remaining close to the previous level at 600 bhp. Although the flagship 7-series was marked m760i in the USA and m760Li is some markets, all N74B66TU V12 powered 7-series were long wheelbase (G12); there was no short wheelbase (G11) variant offered world wide.
Applications:
- 2016–2022 G12 M760Li xDrive[8][9][10]
N74B68
[edit]The 6.75 litre version was introduced in the 2018 Rolls-Royce Phantom. It is also used in the Rolls-Royce Cullinan and Rolls-Royce Ghost, both of which are built on the same platform as the new Phantom.[11]
Applications:
- 2017–present Rolls-Royce Phantom VIII
- 2018–present Rolls-Royce Cullinan
- 2021–present Rolls-Royce Ghost
References
[edit]- ^ a b c "2010 BMW 760Li – Second Drive – Car Reviews". www.caranddriver. Archived from the original on 7 July 2017. Retrieved 12 March 2017.
- ^ a b Hans-Stefan Braun, Thomas Brüner, Klaus Hirschfelder, Uwe Hoyer, Horst Kellerer, Johann Schopp, Christian Schwarz: Der neue Zwölfzylinder-Ottomotor von BMW Archived 2021-10-06 at the Wayback Machine, in MTZ - Motortechnische Zeitschrift, November 2009, Volume 70, Issue 11, pp. 848
- ^ a b "Information on N74 engines". www.bmwheaven.com. Archived from the original on 6 October 2021. Retrieved 11 August 2017.
- ^ 25 years of BMW 12-cylinder engines: setting new standards in the luxury class. Munich, Germany: BMW Corporate Communications. October 2012. Archived from the original on 12 August 2017. Retrieved 11 August 2017.
- ^ "BMW N74 engine". www.australiancar.reviews. Archived from the original on 6 January 2017. Retrieved 12 March 2017.
- ^ "BMW N73 and N74 V12 Engines". www.unixnerd.demon.co.uk. Archived from the original on 1 October 2017. Retrieved 11 August 2017.
- ^ "BMWBLOG Road Review: 2013 BMW 760Li – The Power of 12". www.bmwblog.com. 9 November 2012. Archived from the original on 6 October 2021. Retrieved 11 August 2017.
- ^ "The new BMW M760Li xDrive". www.bmwgroup.com. Archived from the original on 12 August 2017. Retrieved 11 August 2017.
- ^ "Watch BMW's twin turbo all wheel drive V12 G11 M760li hustle to 162 miles per hour". www.bimmerboost.com. Archived from the original on 12 August 2017. Retrieved 11 August 2017.
- ^ "BMW N74B66TU / M760li xDrive". www.drive2.ru (in Russian). 29 March 2016. Archived from the original on 6 October 2021. Retrieved 11 August 2017.
- ^ "RealOEM.com - Online BMW Parts Catalog". www.realoem.com. Archived from the original on 20 November 2017. Retrieved 20 November 2017.