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- เผยแพร่เมื่อ 26 ธ.ค. 2024
- Before the construction of the first prototype of the 501, Böning had calculated the mass of the car as designed, and realized that the six-cylinder engine would be barely adequate to power the car. He proposed the development of a larger engine to power future versions of the car to the management, who accepted his proposal. Böning began the design and development of a V8 engine similar in general design to the then-new Oldsmobile Rocket V8, with a single camshaft in the vee operating overhead valves in wedge-shaped combustion chambers through pushrods.The BMW OHV V8 engine differed from its Detroit contemporaries in the use of an aluminium alloy block with cast-iron cylinder liners, and in its smaller size, initially with a 74 millimetres (2.9 in) bore and a 75 millimetres (3.0 in) stroke, giving a displacement of 2,580 cc (157 cu in).[13][14] The development of the V8 was completed by Fritz Fiedler, who replaced Böning as BMW's chief engineer in 1952.
The V8 engine was introduced at the 1954 Geneva Motor Show as the engine of the new BMW 502 saloon car. Using the same chassis and basically the same body as the 501, the 502 was more luxuriously appointed and, with its light V8 engine producing 100 horsepower (75 kW) with a single two-barrel Solex carburettor, was much faster. The published top speed of 160 km/h (99 mph) was far higher than that of the first six-cylinder version of the Ponton Mercedes launched the same year. At the time of its introduction the 502 was reportedly Germany's fastest passenger sedan in regular production.
The 502 was acclaimed as Germany's first post-war V8 powered car, but its high price of DM17,800 led to low sales; only 190 were sold in its first year of production.
The 502 was distinguished from the 501 by additional chrome trim and more lavish interior fittings. Fog lights and individual front seats were also now included as standard features. The 502 was mildly restyled in 1955 with a wraparound rear window.
As well as the saloon version, BMW offered Baur built two-door cabriolet and coupé versions of the 502 in 1954 and 1955. 501s and 502s were also converted into ambulances and hearses.
A further development of the V8 engine was introduced at the 1955 Frankfurt Motor Show. This had a 82 millimetres (3.2 in) bore, giving a capacity of 3,168 cc (193.3 cu in). The engine made its debut in four new cars at the show, the 507 two-seat convertible, the 503 coupe, the 505 limousine prototype, and the BMW 3.2, a development of the 502 that did not have a model number and was identified simply by its displacement in litres. As used in the 3.2 and the 505, the engine had a compression ratio of 7.2:1, up from the 7.0:1 of the original 2.6 L V8 engine. In this tune, the engine yielded 120 horsepower (89 kW). The final drive ratio was raised from 4.225:1 on the smaller-engined sedans[6] to 3.89:1 on the 3.2 to reduce the fuel consumption of the larger engine.
In 1957, the 3.2 Super with a 140 horsepower (100 kW) engine, was released. The 3.2 and 3.2 Super were continued under these model designations until 1961 with only two notable changes: Power steering became an option in 1959, while front disc brakes were added to the 3.2 Super in October 1959 and to the 3.2 in 1960.
BMW 3200L and 3200S
In 1961, the 3.2 and 3.2 Super were replaced by the 3200L and 3200S respectively. The 3200L had a single carburettor engine that produced 140 horsepower (100 kW), while the 3200S had a twin carburettor engine that produced 160 horsepower (120 kW) at 5600 revolutions per minute.
A report on a 3.2-litre BMW saloon estimated the 502's consumption at 15 L/100 km (19 mpg‑imp; 16 mpg‑US).
Production ended in 1963.
