| BMW N74 engine | |
| Production: | 2009–present |
| Configuration: | 60° V12 |
| Predecessor: | BMW N73 |
| Valvetrain: | DOHC with VVT |
| Displacement: | 5972cc (2009–2015) 6592cc (2009–2022) 6749cc |
| Bore: | 89mm |
| Stroke: | 80mm 88.3mm 90.4mm |
| Block: | Aluminium |
| Head: | Aluminium |
| Fueltype: | Petrol |
| Turbocharger: | Twin-turbo |
| Power: | NaNhp |
| Torque: | NaNlbft |
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.
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 11.61NaN1. 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
Like its predecessor, the N74 has direct injection, DOHC and variable valve timing (called double-VANOS by BMW).[1] [2] However, the N74 does not have variable valve lift (called Valvetronic by BMW).[3]
The N74 marked BMW's first use of an 8-speed automatic transmission, in the form of the ZF 8HP90.[4]
| Engine | Displacement | Power | Torque | Year | |
|---|---|---|---|---|---|
| N74B60[5] | 5972abbr=onNaNabbr=on | 4000NaN0 at 5,250 rpm | 7500NaN0 at 1,500–5,000 rpm | 2008–2015 | |
| N74B66 | 6592abbr=onNaNabbr=on | 4200NaN0 at 5,250 rpm | 7800NaN0 at 1,500–5,000 rpm | 2009–2020 | |
| 4650NaN0 at 5,600 rpm | 8000NaN0 at 1,500–5,500 rpm | 2013–2022 | |||
| 4420NaN0 at 5,250 rpm | 8400NaN0 at 1,500 rpm | 2016–2020 | |||
| 4490NaN0 at 5,500 rpm | 8000NaN0 at 1,500 rpm | 2016–2019 | |||
| 447.50NaN0 at 5,500 rpm | 8500NaN0 at 1,550 rpm | 2020–2022 | |||
| 6750abbr=onNaNabbr=on | 4200NaN0 at 5,250 rpm | 9000NaN0 at 1,500 rpm | 2017–present |
This initial version of the N74 has a bore of 891NaN1 and a stroke of 801NaN1. The redline is 7000 rpm and the compression ratio is 10.0:1.[6]
Applications:
The N74B66 is an enlarged version of the N74B60, due to a stroke of 881NaN1. The redline is 7000 rpm and the compression ratio is 10.0:1. It produces up to 624hp and is used in the Rolls-Royce Ghost.[4]
| Year | Application | Power output | Torque | |
|---|---|---|---|---|
| 2010–2020 | 563hp | 575lbft | ||
| 2014–2020 | 593hp | 575lbft | ||
| 2019 | Eadon Green Panthean Coupe | 619.5lbft | ||
| 2014– | 624hp | 590lbft | ||
| 2015– | 563hp | 605lbft |
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:
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: