Have you ever wondered how car commercials looked back in the day? What about BMW TV commercials? A new video surfaces on Youtube showing the Isetta, a BMW iconic car.
The TV commercial was shots in the 1950s and portrays Isetta as the re-entry for BMW in the automotive market with a price point geared towards a larger demographic.
The first BMW Isetta appeared in 1955 and it was powered by a BMW one-cylinder, four-stroke, 247 cc motorcycle engine making 13 hp (10 kW).
The BMW Isetta 250 started to become even more popular and the car was also redesigned to take a modified version of the 250 cc 4-stroke engine from the BMW R25/3 motorcycle and the front suspension was changed. The single-cylinder generated 12 hp (9 kW) at 5800 rpm. The crankcase and cylinder were made of cast iron, the cylinder head of aluminium. However, the head was rotated by 180 degrees compared with the motorcycle engine. The twin-bearing crankshaft was also different in the Isetta power unit, being larger and featuring reinforced bearings.
The power train from the four-speed gearbox to the two rear wheels was also unusual: fixed to the gearbox output drive was something called a Hardy disc, which was a cardan joint made of rubber. On the other side of it was a cardan shaft, and finally a second Hardy disc, which in turn was located at the entrance to a chain case. A duplex chain running in an oil bath led finally to a rigid shaft, at each end of which were the two rear wheels. Thanks to this elaborate power transfer, the engine-gearbox unit was both free of tension and well soundproofed in its linkage to the rear axle.
Isetta 300 has seen some improvements from the previous version. The bubble windows were replaced by longer, slidding side windows and BMW had enlarged the single cylinder to a 72 mm bore and 73 mm stroke, which gave a displacement of exactly 298 cc, and at the same time they raised the compression ratio from 6.8 to 7.0:1. In this way the engine now generated 13 hp (10 kW) at 5200 rpm, and the torque rose to 18.4 N·m at 4600 rpm. The maximum speed remained at 85 km/h (53 mph). Isetta 300 was still possible to be driven without a license despite the fact that from 1956 first-time drifvers had to pass the test for Class III if they wanted to drive an automobile.
[Source: BimmerToday ]
Author: Horatiu Boeriu
Source: http://www.bmwblog.com/2011/08/10/germa ... mw-isetta/