Porsche flat-twelve engine
| Porsche flat-12 engine | |
|---|---|
| Overview | |
| Manufacturer | Porsche |
| Production | 1969–1973 |
| Layout | |
| Configuration | 180° flat-12 |
| Displacement | 4.5 L (4,494 cc) 5.0 L (4,999 cc) 5.4 L (5,374 cc) |
| Cylinder bore | 85 mm (3.3 in) 86.8 mm (3.4 in) 90 mm (3.5 in) |
| Piston stroke | 66 mm (2.6 in) 70.4 mm (2.8 in) |
| Valvetrain | 24-valve, DOHC, two-valves per cylinder |
| Combustion | |
| Turbocharger | Yes (Twin-turbocharged; some models) |
| Fuel system | Multiport Mechanical Fuel Injection |
| Fuel type | Gasoline |
| Oil system | Dry sump |
| Cooling system | Air-cooled |
| Output | |
| Power output | 520–1,600 hp (388–1,193 kW) |
| Torque output | 350–1,450 lb⋅ft (475–1,966 N⋅m) |
Porsche produced a series of naturally-aspirated, and later an extremely powerful twin-turbocharged flat-twelve engine for their Porsche 917 sports prototype; between 1969 and 1973.