BMW N73
The BMW N73 is a naturally aspirated V12 petrol engine which replaced the BMW M73 and was produced from 2003–2016. It was used in the BMW 7 Series and Rolls-Royce Phantom.
| BMW N73 engine | |
|---|---|
 | |
| Overview | |
| Production | 2003–2016 |
| Layout | |
| Configuration | 60° V12 |
| Displacement | 6.0–6.75 L (366–412 cu in) |
| Valvetrain | DOHC w/ VVT & VVL |
| Combustion | |
| Fuel type | Petrol |
| Chronology | |
| Predecessor | BMW M73 |
| Successor | BMW N74 |
The N73 was the world's first production V12 engine to use gasoline direct port injection.[1]
Compared with its M73 predecessor, the N73 has dual overhead camshafts, double-VANOS (variable valve timing) and valvetronic (variable valve lift).[2][3]
Design
The variable valve timing (VANOS) is a continuously variable design and is present on both the intake and exhaust camshafts. The VANOS units were designed as integral components of the chain drive, and the adjustment ranges are 63 degrees for the intake camshaft and 60 degrees for the exhaust camshaft.[4] The redline for the N73 is 6,500 rpm.
The N73 engine also has variable valve lift (valvetronic), which varied intake valve opening lift from 0.30–9.85 mm (0.01–0.39 in), according to engine speed and load. Each cylinder head has a valvetronic assembly – including a motor, control module and position sensor.[4]
The N73 was superseded by the BMW N74, a twin-turbocharged V12 engine.
Versions
| Version | Year | Displacement | Power | Torque | Comp. ratio |
|---|---|---|---|---|---|
| N73B60 | 2003-2008 | 5,972 cc (364.4 cu in) | 327 kW (439 hp) at 6,000 rpm | 600 N⋅m (443 lb⋅ft) at 3,950 rpm | 11.3:1 |
| N73B68 | 2003-2016 | 6,749 cc (411.8 cu in) | 338 kW (453 hp) at 5,350 rpm | 720 N⋅m (531 lb⋅ft) at 3,500 rpm | 11.0:1 |
N73B60
The 5,972 cc (364.4 cu in) version has a bore of 89 mm (3.50 in) and a stroke of 80 mm (3.15 in).[5]
Application:
- 2003-2008 E65/E66 760i/760Li
N73B68
The 6,749 cc (411.8 cu in) version has a bore of 92 mm (3.62 in)and a stroke of 84.6 mm (3.33 in).
Application:
- 2003-2016 Rolls-Royce Phantom[6]
See also
References
- "BMW World- 12-Cylinder Enginges". www.usautoparts.net. Archived from the original on 27 June 2013.
- "BMW 760Li 2002 - Detroit Auto Show". www.caranddriver.com. Retrieved 7 August 2017.
- "2002 BMW 316ti - Review and road test". www.automobilemag.com. Retrieved 7 August 2017.
- "BMW N73 engine". www.australiancar.reviews. Retrieved 7 August 2017.
- "BMW N73 and N74 V12 Engines". www.unixnerd.demon.co.uk. Retrieved 8 August 2017.
- "RealOEM.com - Online BMW Parts Catalog". www.realoem.com. Retrieved 30 November 2017.