Junkers Jumo 210 (L10)

Twelve Cylinder, 60 degree V-form, Petrol engine, four stroke, 6415 built
developed by Kurt Erfurth

Jumo 210 D

The Jumo 210 was a completely different development from the Jumo 204/209 development. This engine was not an Diesel engine as the above, but a classic petrol engine and therefore continued the Junkers L-Series developements. While the Diesel engines were convenient for continous long-range flights at constant power as it was required for Lufthansa's transatlantic flights, the classic petrol engine was more usefull for military demands with short flights and continous power changes. The complete design is total different from the Diesel engines, which had a vertical positioning of the cylinders. The Jumo 210 instead had 12 cylinders positioned in a hanging V-form.

Developement of the Jumo 210 started in 1931 under the conventional petrol engine designator L10. The L10 was first used in static tests on October, 22nd 1932. In 1933 the designator was changed to Jumo 210. Type approval for this engine was achieved in March 1934 and on July 5th 1934 a Junkers W33 was used as a testbed for the first inflight tests. An initial production of the Jumo 210A was also started in 1934. The later Jumo 210B and C were equipped with a ground loader as well as with a loader pressure regulation. The B-series had an airscrew drive of 0,57 for faster fighter aircraft while the C-series had a drive of 0,62 for slower aircraft. The Jumo 210 D/E had the same drives. Additionally they had a two gear loader Jumo 210Da/Ea had higher T/O power.

The Jumo 210G was theworld's first engine with an automatic mixture control unit and a fuel injection system, developed by Dr. Lichte, instead of classical compression. Jumo 210Ga had another loader drive ratio. The airscrew drive was 0,57. It became the most built subtype of the Jumo 210 and was used on the Bf109/110 and the Ju87.

Further developments were planned as Jumo 210F and H, but were not realized. In 1935 the Jumo 210H was used for the further developement of the Jumo 211. A Jumo210S is a special development of the DVL with special regulation mechanisms. Production of the Jumo 210 came to an end in about 1938.

Technical Data:

Aircraft Types equipped with Jumo 210:

Arado Ar80 V2 to V5
The initial prototypes of the Arado fighter Ar80 V1 and V2 were equipped with Rolls Royce Krestel V.
But in 1935 this engine was changed to a Jumo 210C, as the performance was not satisfying.
A total of five Ar80 were built, of which V2 to V5 were equipped with the Jumo 210C.
V4 later was modified and got a Jumo 210G. Nevertheless the Ar80 programme was dropped.

Arado Ar81 V1 to V3
The Arado Ar81 dive bomber was also equipped with the Jumo 210C.
Only three of the dual wing aircraft were built before the programme was stopped.

Focke Wulf Fw 159 V1 to V3
The Focke Wulf fighter design Fw159 was equipped with Jumo 210B/G
Only three prototypes were built before the programme was stopped.

Focke Wulf Fw 187 A
The Focke Wulf fighter aircraft Fw187 was equipped with two Jumo 210D/G.
A total of nine aircraft were built (only V6 got a DB600A, all others had Jumo engines).
The programme at least was stopped, but the aircraft were used for facility defense at Focke Wulf.

Heinkel He 112
The Jumo 210 was also used within the Heinkel fighter design He 112.
Only V1 was equipped with the Rolls Royce Krestel, while V2 and V3 got the Jumo 210C.
The initial A-series He112 of three aircraft got the Jumo 210D/E. (one He112 V8 was equipped with DB600).
Only two aircraft (V9 and V11) of the B-preseries were equipped with Jumo 210E and Jumo 210G.
A small series of He 112B0/B1 were built for Romania with Jumo 210E.
Other He112B2 were built for Spain, but got the DB600.
At least the further development was stopped in 1937/38.

Heinkel He 114 V2
The Heinkel sea surveyer He 114 should be equipped with BMW132 engines.
A the BMW engine was not available at the time of test flights,
the prototypes were equipped with alternate engines. V2 got the Jumo 210E.
As soon as the BMW engine was available, V2 was equipped with the new engine.

Henschel Hs 124 V1 and V3
The Henschel Hs 124 was a parallel design to the Me 110 destroyer.
Two of the three prototypes were equipped with two Jumo 210C in 1936.
Finally the design was dropped.

Junkers Ju87 A
The Jumo 210 was the originally planned engine equipment of the Ju87.
Only the V1 prototype of the Ju87 was equipped with a Rolls Royce Krestel IIS.
All following prototypes were equipped with Jumo 210.
The initial Ju87 series A0, A1 and A2 were equipped with Jumo 210D in 1937.
But since the B-series production the engine changed to Jumo 211.

Messerschmitt Me 109 B, C, and D
The initial production series of the Messerschmitt fighter Me 109 was equipped with Jumo 210.
Only V1 was equipped with Rolls Royce Krestel IIS, while V2 to V8 got a Jumo 210 and V13 to V14 got a DB600.
Since 1936 the B-series (A-series were not built) were mounted with the Jumo 210D
The further improved C-series got the stronger Jumo 210G-1 since 1938,
while the D-series were equipped with Jumo 210D. The latter were also exported to Switzerland.
Starting with the E-series, the Me 109 was equipped with DB601 engines.

Messerschmitt Me 110 A, B
The production of the Messerschmitt destroyer Me 110 was started with Jumo 210B in 1938.
As soon as the stronger Jumo 210G-1 engine became available, production was switched to B-series.
Since the C-series, all Me 110 are equipped with DB engines.

Messerschmitt Me 262V1
The Messerschmitt Me 262 prototype V1 flew first with a Jumo 210G engine
on April, 18th 1941. As both jet engines BMW 003V and Jumo 004A-0 were
not available by the time of the first flight, the prototype was equipped with
the propeller engine. Later the prototype was equipped with BMW003 engines,
but the propeller engine was kept in the nose section for emergencies.
Only V1 was equipped with this engine.

Weblinks:

• Wikipedia.org - Jumo 210 Story, Data, Photos
• Flight International - Junkers Jumo 210 Advertisment, March 1938
• Junkers-EP.de - Jumo 210 Story, Photos
• AlternatHistory.com - Jumo 210 Story, Data and lot of photos, drawings