BMW M73

The BMW M73 is a SOHC V12 petrol engine which replaced the BMW M70 and was produced from 1993-2002. It was used in the BMW E38 7 Series, E31 8 Series and Rolls-Royce Silver Seraph.

BMW M73 engine
Overview
Production	1993–2002
Layout
Configuration	60° V12
Displacement	5.4 L (330 cu in)
Valvetrain	SOHC
Combustion
Fuel type	Petrol
Chronology
Predecessor	BMW M70
Successor	BMW N73

Design

Compared with its M70 predecessor, the M73 features an updated roller-rocker valve-train and an increased displacement, due to a bore increase of 1 mm (0.04 in) and a stroke increase of 4 mm (0.16 in).[1] While most other engines in the BMW range had switched to dual overhead camshafts with four valves per cylinder, the M73 used a single overhead camshalt and with two valves per cylinder.[2]

Some versions of the engine have two separate Bosch Motronic engine control units,[3] while others use a single Siemens ECU.[4]

Versions

Engine	Displacement	Power	Torque	Year
M73B54	5,379 cc (328.2 cu in)	240 kW (322 hp) at 5,000 rpm	490 N⋅m (361 lb⋅ft) at 3,900 rpm	1994
M73TUB54				1998

M73B54

Applications:

• 1994-1998 E38 750i/750iL/L7
• 1994-1999 E31 850Ci

M73TUB54

Due to more stringent emissions standards, the 1999 model year marked the addition of an electronically heated catalyst,[5] variable MAP thermostat, and water cooled alternator.

Applications:

• 1998-2001 E38 750i/750iL/L7
• 1999-2002 Rolls-Royce Silver Seraph

Awards

• 1999 International Engine of the Year - Best Above 4.0 Litre category winner[2]

References

1. "Information on M73 engines". www.bmwheaven.com. Retrieved 5 August 2017.
2. "BMW Super Bild Of The Day: 5.4 liter BMW V12". www.bmwblog.com. Retrieved 5 August 2017.
3. M73 Training Reference Manual (PDF). p. 2. Retrieved 10 April 2017.
4. "E38 750iL Engine electrical system engine". www.realoem.com. Retrieved 10 April 2017.
5. "BMW M70, M72 and M73 V12 Engines". www.unixnerd.demon.co.uk. Retrieved 5 August 2017.

See also

• List of BMW engines