| BMW M40 engine | |
|---|---|
 |
|
| Overview | |
| Manufacturer | BMW |
| Production | 1987–1994 |
| Layout | |
| Configuration | Naturally aspirated straight-4 |
| Displacement |
|
| Cylinder bore | 84 mm (3.31 in) |
| Piston stroke | 72 mm (2.83 in) 81 mm (3.19 in) |
| Cylinder block material | Cast iron |
| Cylinder head material | Aluminium |
| Valvetrain | SOHC |
| Combustion | |
| Fuel system | Fuel injection |
| Management | Bosch Motronic 1.3 or 1.7 |
| Fuel type | Petrol |
| Cooling system | Water cooled |
| Chronology | |
| Predecessor | BMW M10 |
| Successor | BMW M43 |
The BMW M40 is an SOHC straight-four petrol engine which was produced from 1987–1994. It served as BMW’s base model four-cylinder engine and was produced alongside the higher performance BMW M42 DOHC four-cylinder engine from 1989 onwards.
Compared with its M10 predecessor, the M40 uses a belt-driven camshaft, and hydraulic tappets. Like the M10, the M40 uses an iron block and an aluminium head. Fuel injection for the E30 versions is Bosch Motronic 1.3, and the E36 versions use Bosch Motronic 1.7.
Following the introduction of the BMW M43 engine in 1991, the M40 began to be phased out.
Versions
| Version | Displacement | Power | Torque | Year |
|---|---|---|---|---|
| M40B16- E30 version |
1,596 cc (97.4 cu in) | 73 kW (99 PS; 98 hp) at 5,500 rpm |
141 N⋅m (104 lb⋅ft) at 4,250 rpm |
1987 |
| M40B16- E36 version |
75 kW (102 PS; 101 hp) at 5,500 rpm |
143 N⋅m (105 lb⋅ft) at 4,250 rpm |
1991 | |
| M40B18- E30 version |
1,796 cc (109.6 cu in) | 83 kW (113 PS; 111 hp) at 5,500 rpm |
162 N⋅m (119 lb⋅ft) at 4,250 rpm |
1987 |
| M40B18- E36 version |
85 kW (116 PS; 114 hp) at 5,500 rpm |
165 N⋅m (122 lb⋅ft) at 4,250 rpm |
1991 |
M40B16
The M40B16 is a 1,596 cc (97.4 cu in) version of the M40, which has a bore of 84 mm (3.3 in) and a stroke of 72 mm (2.8 in). It produces 73 kW (98 hp) and 142 N⋅m (105 lb⋅ft).
Applications:
- 1988–1994 316i (E30)
- 1990–1994 316i (E36)
- 1992–1993 Bertone Freeclimber 2
M40B18
The M40B18 is a 1,796 cc (109.6 cu in) version of the M40, which has a bore of 84 mm (3.3 in) and a stroke of 81 mm (3.2 in). It produces 83 kW (113 PS) and 163 N⋅m (120 lb⋅ft).
Applications:
- 1987–1994 318i (E30)
- 1992–1993 318i (E36)
- 1989-1994 518i (E34)
See also
- List of BMW engines
References
