BMW M73

BMW M73 engine
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

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.

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 camshaft 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 (326 PS; 322 hp) at 5,000 rpm	490 N⋅m (361 lb⋅ft) at 3,900 rpm	1994
M73TUB54	5,379 cc (328.2 cu in)	240 kW (326 PS; 322 hp) at 5,000 rpm	490 N⋅m (361 lb⋅ft) at 3,900 rpm	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.