| Porsche flat-6 engine | |
|---|---|
 | |
| Overview | |
| Manufacturer | Porsche |
| Production | 1963–present |
| Layout | |
| Configuration | Flat-6 |
| Displacement | 2.0–4.2 L (122–256 cu in) [1] |
| Cylinder bore | 80–102.7 mm (3.1–4.0 in) [2] [3] |
| Piston stroke | 66–80.4 mm (2.6–3.2 in) [4] [5] |
| Valvetrain | 12-valve or 24-valve, SOHC/DOHC, two-valves per cylinder or four-valves per cylinder [6] |
| Combustion | |
| Turbocharger | Yes (some models) |
| Fuel system | Mechanical fuel injection Carburetor Direct fuel injection |
| Fuel type | Gasoline |
| Oil system | Dry sump |
| Cooling system | Air-cooled [7] Water-cooled |
| Output | |
| Power output | 110–850 hp (82–634 kW) |
| Torque output | 119–730 lb⋅ft (161–990 N⋅m) |
| Dimensions | |
| Dry weight | 387–507 lb (176–230 kg) |
The Porsche flat-six engine series is a line of mechanically similar, naturally aspirated and sometimes turbocharged, flat-six boxer engines, produced by Porsche for almost 60 consecutive years, since 1963. [8] [9] The engine is an evolution of the flat-four boxer used in the original Volkswagen Beetle. [10] [11] [12]
Contents
The flat-six engine is most often associated with their 911 model, Porsche's flagship rear-engined sports car which has used flat-six engines exclusively since 1963. [13] The engines were air-cooled until 1999, when Porsche started using water-cooled engines. [14] [15] [16] [17]
In April 2011, Porsche announced the third generation of the 997 GT3 RS with an enlarged 4.0-litre engine having a power output of 500 PS (368 kW; 493 hp). The naturally-aspirated 4.0-litre flat-six engine (the largest engine displacement offered in a street-legal 911) was introduced with their 2011 911 (997) GT3 RS 4.0, in 2011. [18] The engine itself uses the crankshaft from the RSR with increased stroke dimensions (from 76.4 mm to 80.4 mm). This change increased the power output to 500 PS (368 kW; 493 hp) at 8,250 rpm and 460 N⋅m (339 lbf⋅ft) of torque at 5,750 rpm. [19] giving it a power-to-weight ratio of 365 hp per ton. Only 600 cars were built. [18] [20] At 493 hp (368 kW), [21] the engine is one of the most powerful six-cylinder naturally aspirated engines in any production car with a 123.25 hp (92 kW) per litre output. [22] [6] [23] [24] [25]
Other Porsche models that use flat-six engines are the 1970–1972 Porsche 914/6 (mid-engine), the 1986–1993 Porsche 959 (rear-engine), and the 1996–2021 Porsche Boxster/Cayman (mid-engine). [26] [27] [28]
The Porsche 962 sports prototype also used a twin-turbocharged flat-six engine. [29] [30] [31] [32]
