The Bramo 323 ''Fafnir'' is a nine-cylinder

radial Radial is a geometric term of location which may refer to: Mathematics and Direction * Vector (geometric), a line * Radius, adjective form of * Radial distance, a directional coordinate in a polar coordinate system * Radial set * A bearing f ...

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...

of the

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

era. Based heavily on

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

Bramo Siemens-Schuckert (or Siemens-Schuckertwerke) was a German electrical engineering company headquartered in Berlin, Erlangen and Nuremberg that was incorporated into the Siemens AG in 1966. Siemens Schuckert was founded in 1903 when Siemens & Ha ...

's earlier experience producing the Bristol Jupiter under licence, the Bramo 323 saw limited use.

Design and development

Development of the 323 was the end result of a series of modifications to the original Jupiter design, which Siemens licensed in 1929. The first modifications produced the Sh.20 and Sh.21. The design was then bored out to produce the 950 hp (708 kW) Sh.22 in 1930. Like the Jupiter, the Sh.22 featured a rather "old" looking arrangement with rather prominent valve pushrods on the front of the engine. In the mid-1930s the

Reich Air Ministry The Ministry of Aviation (german: Reichsluftfahrtministerium, abbreviated RLM) was a government department during the period of Nazi Germany (1933–45). It is also the original name of the Detlev-Rohwedder-Haus building on the Wilhelmstrasse ...

(RLM) altered the way in which engines were assigned code names, and Bramo was given the 300-block of numbers. Therefore, the Sh.14 and Sh.22 became the 314 and 322, respectively. The 322 never matured and remained unreliable. The team continued work on the basic design, adding

fuel injection Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

and a new

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

. The resulting Bramo 323 was just under 27 L in

displacement Displacement may refer to: Physical sciences Mathematics and Physics * Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

, and produced 900 PS at 2,500 rpm for takeoff, improving slightly to 1,000 PS at . The reduced power at sea level was inevitable for engines with single-speed, mechanically-driven superchargers when they were regulated to a constant maximum boost pressure below their critical altitude. The Fafnir powered a number of German prewar designs, including the

Focke-Wulf Fw 200 The Focke-Wulf Fw 200 ''Condor'', also known as ''Kurier'' to the Allies (English: Courier), was a German all-metal four-engined monoplane originally developed by Focke-Wulf as a long-range airliner. A Japanese request for a long-range maritime ...

Henschel Hs 126 The Henschel Hs 126 was a German two-seat reconnaissance and observation aircraft of World War II that was derived from the Henschel Hs 122. The pilot was seated in a protected cockpit under the parasol wing and the gunner in an open rear cockp ...

Dornier Do 24 The Dornier Do 24 is a 1930s German three-engine flying boat designed by the Dornier Flugzeugwerke for maritime patrol and search and rescue. A total of 279 were built among several factories from 1937 to 1945. Design and development The Dorni ...

and

Dornier Do 17 The Dornier Do 17 is a twin-engined light bomber produced by Dornier Flugzeugwerke for the German Luftwaffe during World War II. Designed in the early 1930s as a ''Schnellbomber'' ("fast bomber") intended to be fast enough to outrun opposing a ...

, as well as the Focke Achgelis Fa 223 ''Drache'' helicopter. Its fairly poor fuel economy kept it from more widespread use, and most designs chose the similar

BMW 132 The BMW 132 was a nine-cylinder radial aircraft engine produced by BMW starting in 1933. Design and development BMW took over a license for manufacturing air-cooled radial engines from Pratt & Whitney on 3 January 1928. The nine-cylinder mode ...

instead, whose specific fuel consumption varied between 220 and 240 g/(kW•h) depending on model, whereas the early versions of the Fafnir got about 255 g/(kW•h), a poor figure for the era. The C/Ds, where the supercharger used less power, improved this to 230 g/(kW•h), but were only useful at lower altitudes. BMW bought Bramo in 1939 and continued production to supply the small number of designs that already used it, notably the Do 17. The naming at this point becomes somewhat confusing, with BMW, Bramo and Fafnir being used almost interchangeably depending on the source. 5,500 were produced before the lines were shut down in 1944. The original 323 design was produced in A and B models, differing in the direction they turned. The engines were intended to be installed in A/B pairs, thereby eliminating engine torque across a twin-engine aircraft. The similar C and D models featured a lower supercharger gearing for better performance at lower altitudes, improving takeoff power to 1,000 PS, but reducing the critical altitude. The final versions, P, R and T, featured a two-speed supercharger for better all-around performance. This allowed it to generate 1,000 PS at sea level as in the C/D models, but improved altitude performance considerably, delivering 940 PS at . The R-2 subtype added

MW 50 MW 50 (Methanol-''Wasser'' 50) was a 50-50 mixture of methanol and water (German: ''Wasser'') that was often sprayed into the supercharger of World War II aircraft engines primarily for its anti-detonation effect, allowing the use of increased bo ...

water-methanol injection for added low-altitude performance, boosting power to 1,200 PS at 2,600 rpm.

Variants

;323A:(RH rotation) ;323B:same as A but opposite rotation.(LH rotation) ;323C:lower powered supercharge for take-off. (RH rotation) ;323D:same as C but opposite rotation. (LH rotation) ;323J:(RH rotation) ;323M:(RH rotation) ;323P:2-speed supercharger:- at ;323R :;323R-2:with 'C3'

96 octane An octane rating, or octane number, is a standard measure of a fuel's ability to withstand compression in an internal combustion engine without detonating. The higher the octane number, the more compression the fuel can withstand before detonating ...

fuel injection at 2,600 rpm ;323T:

Applications

Arado Ar 196 The Arado Ar 196 was a shipboard reconnaissance low-wing monoplane aircraft built by the German firm of Arado starting in 1936. The next year it was selected as the winner of a design contest and became the standard aircraft of the ''Kriegsmarin ...

Arado Ar 232 The Arado Ar 232 ''Tausendfüßler'' (German: "Millipede"), sometimes also called ''Tatzelwurm'', was a cargo aircraft, designed and built in small numbers by the German firm Arado Flugzeugwerke during World War II. The design introduced, or br ...

* Blohm & Voss BV 222 *

Focke Achgelis Fa 223 The Focke-Achgelis Fa 223 ''Drache'' () was a helicopter developed by Germany during World War II. A single Bramo 323 radial engine powered two three-bladed rotors mounted on twin booms on either side of the cylindrical fuselage. Although th ...

Junkers Ju 352 The Junkers Ju 352 ''Herkules'' ("Hercules" in German) was a German World War II transport aircraft that was developed from the Junkers Ju 252. Design and development During the late spring of 1942, the Junkers-Dessau project office was instruc ...

Specifications (BMW-Bramo 323J)

Notes

External links

German language article on the Bramo 323 with images
{{BMW aeroengines Aircraft air-cooled radial piston engines BMW aircraft engines 1930s aircraft piston engines