BMW IV
The BMW IV was a liquid-cooled six - cylinder in - line engine with a displacement of 22.9 liters , which was built as an aircraft engine from 1918 by the German manufacturer BMW .
history
The engine designer Max Friz began developing the BMW IV as the successor to the BMW IIIa in the last year of the war .
On June 17, 1919, Franz Zeno Diemer set an altitude record of 9,760 meters with the DFW F 37 / III (also DFW C.IV (T25) ) powered aircraft . This performance was made possible by the aircraft engine BMW IV with an altitude carburetor. The record high was reached in 89 minutes from Oberwiesenfeld airfield . BMW advertised the record as a "world height record"; however, it was not recognized because Germany was not a member of the FAI . This high-altitude flight was preceded by a test flight at 9,200 meters on May 11, 1919, which was also immediately implemented in advertising by BMW.
Under the name Junkers L 5 , the engine was manufactured under license by Junkers Motorenbau GmbH from 1925 .
construction
It is a water-cooled six-cylinder in-line engine. The crankcase of an aluminum alloy is split horizontally. The crankshaft is made of gray cast iron , seven slide bearings are used as crankshaft bearings . The cast iron cylinders are arranged individually on the crankcase and have a welded-on sheet steel jacket for water cooling. The pistons each have three piston rings . The overhead camshaft ( OHC valve control ) is driven by a vertical shaft. The hanging valves are operated by roller rocker arms.
A single BMW “height” carburetor takes care of the mixture formation . The Doppelzündanlage (two spark plugs per cylinder) consists of two Bosch - magnetos . The firing order is: 1–5–3–6–2–4. The pressure circulation lubrication is maintained with a piston oil pump. A cooling water pump circulates the coolant.
use
The BMW IV was used as a propulsion system on a number of aircraft. In particular, it was also used on prototypes and record flights.
Technical specifications
| Parameters | Data of the BMW IV |
|---|---|
| design type | Liquid-cooled six - cylinder in - line engine , vertical ( crankshaft below), without supercharging |
| Valve control | an overhead camshaft ( OHC ), driven by the crankshaft via a vertical shaft, two valves per cylinder |
| Displacement ( bore × stroke ) | 22.9 liters (160 mm × 190 mm) |
| Compression ratio | 5.5 |
| Dry matter | 290 kg |
| Starting power | 300 PS (approx. 220 kW ) |
| Continuous (travel) performance | 250 hp (180 kW ) at 1400 min -1 |
See also
literature
- Kyrill von Gersdorff, Kurt Grasmann: aircraft engines and jet engines . Bernard & Graefe Verlag, 1981, ISBN 3-7637-5272-2 .
Web links
- BMW IV. In: BMW History. BMW AG, accessed on May 14, 2016 (dossier of the BMW Group Archives).
- Christian Pierer: The history of BMW aircraft engines. In: BMW history. BMW AG, 2007, pp. 14–21 , accessed on May 14, 2016 (Mobile Tradition live - issue 01/2007).
- In-line six-cylinder aircraft engine type BMW IV. In: BMW History. BMW AG, 1918, accessed on September 12, 2014 (drawing in side view).
Individual evidence
- ↑ Franz Zeno Diemer's record high altitude flight. In: BMW history. BMW AG, June 17, 1919, accessed on May 14, 2016 (document in the BMW Group Archive): “The BMW test pilot Franz Zeno Diemer starts on June 17, 1919 with a DFW-F 37 / III (“ C-IV ”) from Oberwiesenfeld and sets the first (still unofficial) BMW world record; a high-altitude record over 9,760 m with an aircraft powered by a BMW Motor IV, a successor to the IIIa. "
- ↑ The German altitude record: 9200 meters. In: BMW history. BMW AG, May 11, 1919, accessed on May 14, 2016 (document in the BMW Group Archive).
- ↑ a b Description and operating instructions for the Bavaria aircraft engine type BMW IV. In: BMW Geschichte. BMW AG, 1918, accessed on May 14, 2016 (manual with pictures, 49 pages): "Description of the engine, mode of operation, installation, dismantling, operation (regulations, faults and remedies)"