Schwezow ASch-2K
The Schwezow ASch-2K ( Russian Швецов АШ-2К ) was an aircraft engine with 28 cylinders from Soviet production. It was developed at the Aviadwigatel aircraft engine plant in Perm in the late 1940s to early 1950s .
It was an air-cooled 28-cylinder multiple radial engine with four 7-cylinder stars arranged one behind the other. The four 7-cylinder stars were each offset by 12.857 ... ° (360 ° / 28), so that the rear cylinder planes looked through between the planes in front of them, in order to get the most effective airflow possible for cooling. Its one-piece crankshaft had four cranks that were offset by 90 °. This ensured an even firing sequence (one ignition every 25.714 ... ° crankshaft revolution). The engine was supercharged to increase performance. In 1949 it reached 4700 hp.
Its forerunner was the ASch-2TK ( АШ-2ТК ) from 1946, which differed only in the charging and the power of 4300 HP.
Like the Dobrynin WD-4K , the ASch-2K was intended to drive the Tupolev Tu-85 strategic long-range bomber .
Due to the rapid development of turbo- prop engines, piston engines were soon replaced as aircraft engines, because turbo-prop engines usually achieve mass-specific performance (performance per engine mass) that is unattainable for piston engines and still have very compact dimensions. In the Soviet Union, the following bombers were often powered by the Kuznetsov NK-12s (such as the Tupolev Tu-95 ), which are still the most powerful turboprop engines ever built in the world.
Other examples of such large, air-cooled piston engines are very rare. Only the American Pratt & Whitney R-4360 should be mentioned here. It was of the same design - a 28-cylinder quadruple radial engine.
Technical specifications
- Engine type: 28-cylinder four-star supercharged gasoline engine (four 7-cylinder stars)
- Power: 3460 kW (4700 PS )
- Speed: 2800 / min
- Displacement: 82.42 liters
- Stroke: 155.0 mm
- Bore: 155.5 mm
- specific fuel consumption: 260 g / PSh
- Mass: 2550 kg
- Length 3200 mm
- Diameter: 1580 mm