The McLaren F1 is a sports car designed and manufactured by Gordon Murray and McLaren Automotive. On March 31, 1998, it set the record for the fastest production car in the world, 240 mph (391 km/h). As of April 2009, the McLaren F1 is succeeded by three faster cars in sheer top speed, but is still the fastest naturally aspirated production car.
BMW, headed by engine expert Paul Rosche designed and built a custom-designed 6.1 L (6064 cc) 60-degree V12 engine, which was 14% more powerful than specified and 16 kg (35 lb) heavier - despite being based on the original specifications of 550 bhp (410 kW; 560 PS), 600 mm (23.6 in block length and total weight of 250 kilograms (550 lb).
The final result is a custom-built 6.1 L (6064 cc) 60-degree V12 with an aluminium alloy block and head, 86 mm (3.4 in) x 87 mm (3.4 in) bore/stroke, quad overhead camshafts for maximum flexibility of control over the four valves per cylinder and a chain drive for the camshafts for maximum reliability, the engine is dry sump. At 266 kg (586 lb), the resulting engine was slightly heavier than Murray 's original maximum specification weight of 250 kg (551 lb) but was also considerably more powerful than he had specified. The bespoke engineered engine for the McLaren F1 is called the BMW S70/2.
The carbon fibre body panels and monocoque required significant heat insulation in the engine compartment, so Murray 's solution was to line the engine bay with a highly efficient heat-reflector: gold foil. Approximately 25 g (0.8 ounce) of gold was used in each car.
The road version used a compression ratio of 11:1 to produce 627 hp (468 kW; 636 PS) at 7400 rpm—considerably more than Murray 's specification of 550 horsepower (404 kW). Torque output of 480 ft·lb (651 N·m) at 5600 rpm. The engine has a redline rev limiter set at 7500 rpm.
In contrast to raw engine power, a car's power-to-weight ratio is a better method of quantifying acceleration performance than the peak output of the vehicle's powerplant. The standard McLaren F1 achieves 550 hp/ton (403 kW/tonne), or just 3.6 lb/hp. Compare with the Ferrari Enzo at 434 hp/ton (314 kW/tonne) (4.6 lb/hp), the Bugatti Veyron at 530.2 hp/ton (395 kW/tonne) (4.1 lb/hp), and the SSC Ultimate Aero TT with an alleged 1003 hp/ton (747.9 kW/tonne) (2 lb/hp).