| BMW N73 engine | |
| Production: | 2003 - 2016 |
| Configuration: | 60° V12 |
| Displacement: | 5972cc 6749cc |
| Bore: | 89mm 92mm |
| Stroke: | 80mm 84.6mm |
| Valvetrain: | DOHC w/ VVT & VVL |
| Fueltype: | Petrol |
| Predecessor: | BMW M73 |
| Successor: | BMW N74 |
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.
The N73 was the world's first production V12 engine to use gasoline direct 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]
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 0.3-, 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The N73 was superseded by the BMW N74, a twin-turbocharged V12 engine.
| Version | Year | Displacement | Power | Torque | Comp. ratio | |
|---|---|---|---|---|---|---|
| N73B60 | 2003-2008 | 59721NaN1 | 3270NaN0 at 6,000 rpm | 6000NaN0 at 3,950 rpm | 11.3:1 | |
| N73B68 | 2003-2016 | 67491NaN1 | 3380NaN0 at 5,350 rpm | 7200NaN0 at 3,500 rpm | 11.0:1 |
The 59721NaN1 version has a bore of 892NaN2 and a stroke of 802NaN2.[5]
Application:
The 67491NaN1 version has a bore of 922NaN2and a stroke of 84.62NaN2.
Application: