YEAR 1926

     BMW keeps a leading position in the aeronautical industry. The same commitment to innovation and perfection is rewarded with five world records for the The Rohrbach Ro VII seaplane with a BMW VI engine.

The BMW VI was a water-cooled V-12 aircraft engine built in Germany in the 1926. It was one of the most important German aero engines in the years leading up to World War II.


Design and development

The first twelve-cylinder engine built by the Bayerische Motorenwerke AG, with a 60-degree included angle between the cylinder banks. The BMW VI was developed from the BMW IV by doubling the number of cylinders. Series production commenced in 1926 after type approval had been granted. From 1930 on, after 1000 engines of the BMW VI type had already been delivered, Germany was again permitted to construct military aircraft. The sudden additional demand resulted in the production figures increasing rapidly. In 1933 the BMW VI was used for BMW's first experiments with direct fuel injection.

The BMW VI was the chosen source of power for numerous record-breaking and long-distance flights, including an east-to-west crossing of the Atlantic in 1930 and a round-the world flight in 1932, both by Wolfgang von Gronau in an open Dornier Wal flying boat powered by two BMW VI engines.

The BMW VI was put to unusual use as a power unit for the "Rail Zeppelin" high-speed railcar. Many versions of the BMW VI engine were developed, and it was built under license in Japan and the Soviet Union. This was further evidence of the reliability of an engine with which BMW made a fundamental contribution to the build-up of German air transport. At least 9,200 were built between 1926 and 1938. The engine was license-built in the Soviet Union under the supervision of Mikulin, who then further developed it as the M-17. More license built engines were produced by Kawasaki Heavy Industries in Japan as the Kawasaki Ha-9.


General characteristics

Type: V-12
Bore: 160 mm (6.3 in)
Stroke: 190 mm (7.48 in)
Displacement: 45.84 L (2,797.5 cuin)
Length: 1810 mm (71.26 in)
Width: 859 mm (33.82 in)
Height: 1103 mm (43.43 in)
Dry weight: 510 kg (1124 lb)

Components

Fuel system: 2 x Zenith 60 DCL
Fuel type: min. 87 octane gasoline
Cooling system: Liquid-cooled

Performance

Power output: 650 HP 641 hp
Compression ratio: 5.50

                                                                                               The Rohrbach Ro VII

BMW releases in 1926 R42, with a 494 cm³ engine, and 12PS at 3400 rpm.

 BMW - R42 - 1926-1928

Date 1926-1928
Number sold 6.502
Price 1.510,- RM

Engine internal designation M 43 engine type four-stroke two-cylinder flat-twin bore x stroke 68 x 68 mm displacement 494 cm3 output 12 PS at 3400 rpm compression ratio 4,9 : 1 valves sv carburetion system 1 carburettor BMW Spezial two-valve 22 mm engine lubricating forced-feed lubrication oil pump gear pump Power transmission Clutch single discs, dry no. of gears 3 shifting manual Gear ratios 2,49 / 1,50 / 1,08 rear wheel ratio 1 : 4,53 or 1 : 3,8 (sidecar 1 : 6, 27 or 1 : 5,7) bevel/crown wheel 15 / 68 or 15 / 57 teeth (sidecar 11/ 69 or 10 / 57) Electrical system Alternator magneto generator on request Ignition Bosch magneto ignition Spark plugs Bosch W 175 Suspension designation R 42 frame twin-loop steel tubular frame front wheel suspension plate spring, 5 laminae rear wheel suspension rigid wheel rims deep-bed 19 x 3 or 21 x 2,5 tyres, front 26 x 3,5 on 19 x 3 or 27 x 2,75 on 21 x 2,5 tyres, rear 26 x 3,5 on 19 x 3 or 27 x 2,75 on 21 x 2,5 brakes, front drum brake Ø 150 mm Brakes rear external shoe brake at gearing (on cardan shaft) Dimensions and weights Length x width x height 2100 x 800 x 950 mm Wheel base 1410 mm Tank capacity 14 l Unladen weight, full tank 126 kg (with Original sidecar 188 kg) load rating k.A. Fuel consumption ca. 3 l / 100 km oil consumption ca. 1,7 l / 1000 km Top speed 95 km/h R42 - running engine