BMW VII
 | This article needs additional citations for verification. (April 2018) |
| BMW VIIa | |
|---|---|
| Type | V-12 water-cooled piston engine |
| National origin | Germany |
| Manufacturer | Bayerische Motorenwerke
|
| First run | 1928 |
| Developed from | BMW VI |
| Variants | BMW IX |
The BMW VII was a
supercharging
led to the related BMW IX.
Design and development
The main change from the VI to the VII was the addition of a 0.62 ratio propeller reduction gearing system, allowing the engine to run at higher RPM, and thus higher power settings, while still efficiently driving the same propellers. A more minor change was the movement of the
aluminum alloy or Elektron
.
Operational history
The engine was first built in 1928 and passed its acceptance tests in June 1930. Only a few examples of the BMW VII went into operation, in the single-engined version of the
carburettor
); this led in due course to the development of the BMW IX aircraft engine.
Variants
- Low compression
- A low compression variant ran at 5.5:1 compression ratio, delivering 450 kW (600 hp) at 1,565 rpm
- Medium compression
- A medium compression variant ran at 6:1 compression ratio, delivering 560 kW (750 hp) at 1,650 rpm
- BMW VIIaU
- A high compression variant running at 7.3:1 compression ratio, delivering 560 kW (750 hp) for take-off.
Specifications (variant)
Data from [1]
General characteristics
- Type: V-12 water-cooled piston engine
- Bore: 160 mm (6.30 in)
- Stroke: 190 mm (7.48 in) (nominal:-master/slave connecting rods resulted in different stroke for each cylinder bank)
- Displacement: 46.93 L (2,864 cu in)
- Length: 2,025 mm (79.72 in)
- Width: 864 mm (34.02 in)
- Height: 1,045 mm (41.14 in)
- Dry weight: 525 kg (1,157 lb)
Components
- Fuel type: Aviation gasoline
- Oil system: pressure fed
- Cooling system: water-cooled
- Reduction gear: 0.62:1
Performance
- Power output: 450 or 560 kW (600 or 750 hp)
- Compression ratio: 5.5 / 6 / 7.3
References
- ISBN 978-3868522143.