Pages

Subscribe:

Ads 468x60px

Friday, November 4, 2011

McLaren F1 Sport I McLaren F1 Engine


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.

The car features numerous proprietary designs and technologies. It is lighter and has a more streamlined structure than even most of its modern rivals and competitors despite having one seat more than most similar sports cars, with the driver's seat located in the middle. It features a powerful engine and is somewhat track oriented, but not to the degree that it compromises everyday usability and comfort. It was conceived as an exercise in creating what its designers hoped would be considered the ultimate road car. Despite not having been designed as a track machine, a modified race car edition of the vehicle won several races, including the 24 Hours of Le Mans in 1995, where it faced purpose-built prototype race cars. Production began in 1992 and ended in 1998. In all, 106 cars were manufactured, with some variations in the design.

Engine

Gordon Murray insisted that the engine for this car be naturally aspirated to increase reliability and driver control. Turbochargers and superchargers increase power but they increase complexity and can decrease reliability as well as introducing an additional aspect of latency and loss of feedback, the ability of the driver to maintain maximum control of the engine is thus decreased. Murray initially approached Honda for an NA powerplant with 550 bhp (410 kW; 560 PS), 600 mm (23.6 in) block length and a total weight of 250 kg (551 lb), it should be derived from the Formula One powerplant in the then-dominating McLaren/Honda cars.

When Honda refused, Isuzu, then planning an entry into Formula One, had a 3.5 V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the McLaren F1. However, the designers wanted an engine with a proven design and a racing pedigree.

In the end BMW took an interest, and the motorsport division BMW M headed by engine expert Paul Rosche designed and built Murray 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.