| 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.[1][2] 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,[3] 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,[4] and the E36 versions use Bosch Motronic 1.7.[5][6]
Following the introduction of the BMW M43 engine in 1991, the M40 began to be phased out.
- ^ "BMW M40B18 automotive engine". bmw-grouparchiv.de. Retrieved 15 August 2019.
- ^ "BMW M40B16 automotive engine". bmw-grouparchiv.de. Retrieved 15 August 2019.
- ^ "M40 - E30 Zone Wiki". www.e30zone.net. Archived from the original on 4 October 2008. Retrieved 27 January 2017.
- ^ "3' E30 318i Uncoded DME control unit". www.realoem.com. Retrieved 1 February 2017.
- ^ "3' E36 318i Uncoded DME control unit". www.realoem.com. 27 October 1975. Retrieved 1 February 2017.
- ^ Roy McNeill, Copyright BMW World 1999–2005. "BMW World – 4-Cylinder Engines". Usautoparts.net. Archived from the original on 2014-03-02. Retrieved 2012-05-29.
{{cite web}}: CS1 maint: numeric names: authors list (link)