- Based on the Japanese Wikipedia article
| Daihatsu J engine | |
|---|---|
 JB-JL engine in Daihatsu Move (L602) | |
| Overview | |
| Manufacturer | Daihatsu |
| Production | 1994–2012 |
| Layout | |
| Configuration | Inline-4 cylinder |
| Displacement | 659 cc 713 cc |
| Cylinder bore | 56.4 mm (2.22 in) 61.0 mm (2.40 in) |
| Piston stroke | 61.0 mm (2.40 in) |
| Cylinder block material | Aluminium alloy |
| Cylinder head material | Aluminium alloy |
| Valvetrain | DOHC 16-valve |
| Compression ratio | 8.0–10.0:1 |
| Combustion | |
| Fuel system | Fuel injection |
| Fuel type | Petrol |
| Cooling system | Water-cooled |
| Output | |
| Power output | 58–120 PS (57–118 hp; 43–88 kW) |
| Torque output | 57–128 N⋅m (5.8–13.1 kg⋅m; 42–94 lbf⋅ft) |
| Chronology | |
| Successor | Daihatsu EF engine |
The Daihatsu J-series engine is a series of the inline-four engines specially for Daihatsu's kei cars that was produced from August 1994 to August 2012. This was the only inline-four engine for Daihatsu's kei cars, debuted in the L502 Daihatsu Mira that was launched in September 1994.
It features smooth engine rotation, low noise, less vibration and quite powerful power in its class (turbo version). But since the stroke is short and volume per cylinder is small (164.75 cc) compared to the inline-three engine (±220 cc, which is common for kei cars), the torque characteristics and fuel consumption in the lower rpm is not that great compared to inline-three engine. For this reason, it can be said that the engine is more specialized for sport driving rather than "stop and go city driving".
On 31 August 2012, as the production of the first Daihatsu Copen ended, the production of the J-series engine ended as well. Daihatsu has announced that it will integrate the engine for kei cars into inline-three in the future (EF engine).