Bramo 323

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Bramo 323 Fafnir
Bramo 323.JPG
Type: Radial engine
Design country:

German Reich NSGerman Reich (Nazi era) German Empire

Manufacturer:

Brandenburg engine works

Production time:

1936 to 1944

Number of pieces:

approx. 5500

The Bramo 323 " Fafnir " is an air-cooled nine-cylinder radial engine from Brandenburgische Motorenwerke (from 1939: BMW-Flugmotorenwerke Brandenburg). The aircraft engine was based on the experience that Siemens & Halske and SAM / Bramo had made with the Gnôme-Rhône 9A Jupiter engines (a replica of the Bristol Jupiter ) built under a license from Gnôme-Rhône . With the Bramo 323, Siemens & Halske took over the basic valve arrangement of the leading American radial engines, which allows a much better cooling of the cylinder heads. The Bramo 323 thus became one of the most powerful nine-cylinder radial engines. By 1944 approx. 5,500 "Fafnir" had been produced.

development

The development began with the construction of the Bristol Jupiter in a "German" version, the Sh.20 and Sh.21 in 1929. When the bore was enlarged, the Sh.22 was created in 1930 with 950 hp (708 kW). The Sh.22 with the forward rails looked analogous to Jupiter bumpers of the valve control from quite dated. The aircraft engine production was separated from the Siemens & Halske concern in 1934 and transferred to the newly created subsidiary Siemens Apparate und Maschinen GmbH (SAM). In the mid-1930s, all German aircraft engine designations were changed, with the SAM being assigned to the 300 block. After Bramo was founded in 1936, the SAM 314 was renamed Bramo 314 and the SAM 322 was renamed Bramo 322. The Bramo 322 was never ready for series production.

The development is now focused on the basic design, looking for the bramo 323 a Junkers - gasoline direct injection with supercharger before. The engine had a displacement of just under 27 l and produced 900 hp take-off power at 2500 rpm, which rose slightly to 1000 hp in 3100 m. The drop in performance at sea level is due to the principle of the mechanically driven charger, which only builds up a constant boost pressure above the critical flight altitude.

The original Bramo 323 was produced in an A and B variant, which differed in the direction of rotation. The engines were intended to be installed in pairs in twin-engine aircraft, so that the torque of the propellers is balanced. The same applies to the C and D variants, where the charger ratio has been reduced for better performance at a lower altitude. This increased the take-off power to 1000 hp, but the critical flight altitude was reduced.

The final versions P, R and T were equipped with a mechanical charger that could be switched between two stages for higher performance at all flight altitudes. This achieved 1000 PS at sea level as in the C / D variant, but improved altitude performance with 940 PS at 4570 m altitude. In the R-2 variant, a MW-50 water-methanol injection was provided for an increase in performance at low altitudes, which brought 1200 hp at 2600 rpm.

Applications

With the Bramo 323 Fafnir some German pre-war models were powered, for example. B. the Focke-Wulf Fw 200 , Henschel Hs 126 , Arado Ar 232 , Dornier Do 24 and Do 17 as well as the helicopter Focke-Achgelis Fa 223 "Drache" . The first examples of the Blohm & Voss BV 222 “Wiking” flying boat were equipped with the Bramo 323 R-2.

Due to the rather high fuel consumption, the engine was not widely used, as most aircraft rely on the similar BMW 132 , which, depending on the version, had a lower specific fuel consumption of 0.30 and 0.35 kg / kWh than earlier versions of the Fafnir with 0.37 kg / kWh. In the charged variants C and D, the value sank to 0.31 kg / kWh, but this engine was not suitable for high altitudes due to the only single-stage charger.

BMW bought Brandenburg Motor Works in 1939. For the few aircraft - especially the Fw 200 and Do 24 - still used after 1940 the Bramo-Fafnir, which in turned BMW Flugmotorenwerke Brandenburg renamed company's motor, as an exchange unit into the remaining Thu 17, until 1944 ago.

Technical specifications

Bramo 323 A

Aircraft with the Bramo 323

See also

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Web links

Commons : Bramo 323  - Collection of Images
  • Bramo-323. In: BMW history. BMW AG, accessed on May 6, 2019 (dossier of the BMW Group Archives).

Individual evidence

  1. ↑ a b Kyrill von Gersdorff, Helmut Schubert, Stefan Ebert: Aero engines and jet engines . In: German aviation . 4th edition. tape 2 . Bernard & Graefe, Bonn 2007, ISBN 978-3-7637-6128-9 , pp. 47-49 .