The
Jumo 211 was an inverted
V-12 aircraft
engine,
Junkers Motoren's
primary
aircraft engine of
World War II. It was the direct competitor to
the famous
Daimler-Benz DB 601
and closely paralleled its development. While the Daimler-Benz
engine was mostly used in fighters and destroyers, the Jumo engine
was primarily used in
bombers such as
Junkers' own
Ju 87 and
Ju 88.
Design and development
The Jumo 211 was developed by Dr. Neugebauer as scaled-up successor
to the earlier
Jumo 210.
In 1934,
even before the new Jumo 210 had completed its acceptance tests,
the RLM
sent out a request for a new 1,000 hp-class engine
of about 500 kg weight. Both Jumo and
Daimler-Benz responded, and in order to reach
service before the new
Daimler-Benz
DB 600, the Jumo team decided to make their new design as
similar as possible to their
210H model, currently
in testing.
The resulting
Jumo 211 was first prototyped at
Jumo's Dessau plant in 1935 and started testing in April 1936. Like
the 210H, it featured a direct fuel injection system powered by
small pistons driven off the crankshaft, three valves per cylinder,
and an inverted V layout. Limited production of the 1,100 hp
Jumo 211A started in April 1937 at Dessau, with
just over 1,000 completed before full production was started at
Magdeburg in July. Three models were provided with varied settings
for its two-speed
supercharger, tuned
for different low-
versus high-altitude performance. The
first aircraft powered by the 211A arrived that November.
But by this time the DB 600 had finally arrived. Unlike the 211,
the 600 was an all-new design that introduced a number of new
features. Notably, it used a pressurized water cooling system that
allowed it to use much less water inside the engine, and resulted
in a smaller and lighter engine and radiator. Additionally, the
higher pressures allowed the water to remain a liquid at all
altitudes, allowing it to keep the engine cool at higher power
settings. The 211's unpressurized cooling system had to lower the
temperature of the coolant as the aircraft climbed in altitude and
the boiling point dropped. Combined with a more powerful
supercharger, the 600 was able to outperform the 211 at medium and
high altitudes, relegating the 211 to lower altitude roles.
Although many designs had already been drawn up using the 211,
including fighters like the
Bf 109 and
Bf 110, these quickly moved to the 600 (and
later the
DB 601). The 211
became the major bomber engine of the war, in no small part due to
Junkers also building most of the bombers then in use.
Development of the 211 continued with the
211B
being released in 1938, with a slightly increased maximum RPM of
2,400 which boosted power to 1,200 hp. The later
211C and
211D differed primarily
in the propeller gear ratios and other features.
A major upgrade was started in 1940 in order to better compete with
the 601, following in its footsteps with a pressurized cooling
system. The resulting
211E proved to be able to
run at much higher power settings without overheating, so it was
quickly followed by the
211F which included a
strengthened crankshaft and a more efficient supercharger. Running
at 2,600 RPM the F and similar J engines delivered a much improved
1,350 hp. Further improvements to this basic line led to the 1,425
hp
211N and 1,475 hp
211P.
Continued development of the 211 line ended in favor of the
re-named
213.
Total production of the 211 series amounted to 68,248 engines with
a production peak of 1700 engines per month in the autumn of
1942.
Variants
- Jumo 211 A
- Jumo 211 Ba
- Jumo 211 Da
- Jumo 211 H, G
- Jumo 211 F (L, M, R)
- Jumo 211 J
- Jumo 211 N
- Jumo 211 P
- Jumo 211 Q
Applications
Specifications (Jumo 211 C)
See also
Comparable engines
References
- Jane's Fighting Aircraft of World War II. London.
Studio Editions Ltd, 1989. ISBN 0-517-67964-7
External links
Wikis
Quiz
Map
Search
