BMW M51

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BMW M51
M51 Motor.JPG
Overview
Manufacturer BMW
Production 1991-2000
Layout
Configuration Inline-6
Displacement 2497 cm3
Cylinder bore 80 mm
Piston stroke 82,8 mm
Cylinder block alloy Cast iron
Valvetrain OHC
Compression ratio 22:1
Combustion
Turbocharger Single turbocharger, tds-engines also have an intercooler
Fuel system Swirl-chamber-injection
Management Bosch DDE 2.1
Fuel type Diesel
Cooling system Water-cooled
Output
Power output 85-105 kW
Torque output 222-280 N·m
Dimensions
Dry weight 132 kg
Chronology
Predecessor BMW M21
Successor BMW M57

The BMW M51 is an inline diesel engine produced by the upper austrian BMW plant in Steyr from July 1991 through February 2000. Its predecessor is the BMW M21, the successor is the BMW M57.

Description[edit]

The M51 is a water-cooled and turbocharged inline six-cylinder diesel engine with a Bosch VP20-swirl-chamber-injection.[1][2] The displacement is 2,497 cc (152 cu in) and the compression ratio is 22:1.

Some engine variants have an intercooler in addition to the turbocharger, they can be identified by the tds.[2] The M51 is an engine made of cast iron, it has one chain driven overhead camshaft[3] and two valves per cylinder.[2][3] Compared to the M21 the M51 now has tappets and a hydraulic valve lash adjustment.[2] The fuel injection in the first engines is controlled by the ECU Bosch DDE 2.1, which was replaced after the first technical revision by the DDE 2.2.[3] This results in greater torque at lower revs.[3] For lubrication SAE 5W-40 oil is used.[4]

Engine Bore × Stroke Power Torque Year
M51D25 UL 80 × 82,8 mm 85 kW
@ 4800 rpm
222 Nm
@ 1900 rpm
1991–1997
M51D25 OL[3] 105 kW
@ 4800 rpm
260 Nm
@ 2200 rpm
1991–1996
X25DT[5][A 1] 96 kW
@ 4800 rpm
250 Nm
@ 1400 rpm
1994–2001
M51D25TÜ UL 85 kW
@ 4800 rpm
230 Nm
@ 1900 rpm
1996–1998
M51D25TÜ OL[3] 105 kW
@ 4800 rpm
280 Nm
@ 2200 rpm
1996–1998
M51D25TÜ OL[3] 105 kW
@ 4600 rpm
1998–2000
M51D25M1[6][A 2] 100 kW
@ 4400 rpm
270 Nm
@ ? rpm
until 1999
  1. ^ For Opel Omega B only
  2. ^ For Range Rover DSE 2.5 P38 LP2 only

Applications:

See also[edit]

External links[edit]

References[edit]