Initial Junkers aircraft of WWI and the early post war phase were mostly equipped with BMW, Mercedes or Benz engines. Junkers himself was not engaged in aircraft engine designs during the early years of Junkers Flugzeugbau. Due to the restrictions on the German aviation industry there were little interest in Germany in improved engines after WWI. Still in 1922/23 there were no really reliable aircraft engine available in Germany. Therefore Junkers decided to go for an own developement in 1923. At this time a small license production of the BMW III engine was already established at Junkers Flugzeugwerke. As BMW was not interested in further engine developements in the early 20s, Junkers Flugzeugwerke were allowed to further improve the BMW IIIa and the BMW IV engines for their own needs.
The Junkers L2 was based on the BMW IIIa engine. It had the same bore and stroke as the original BMW engine. The type approval was achieved in autumn 1924 and serial production started shortly afterwards. It was the first serial produced Junkers aircraft engine. Like the L1 there were several subtypes introduced in 1925, i.e. the L2a with higher turnrate and more power.
The Junkers L2 engine was used on all initial Junkers aircraft of 1924/25. But as it produced not enough power especially for the larger Junkers aircraft as the G23/G24, further developements quickly led to the improved Junkers L5. Just a total of 58 serial produced L2 engines were built.
Aircraft Types equipped with L 2:
The first aircraft to be equipped with the L2 was the Junkers F13.
The initial a-series ba, ca, da, fa were equipped with this engine.
Later versions got the L5 engine.
Only some prototypes of the postal aircraft Junkers A20 got Daimler or BMW IIIa engines.
The serial production line A20b was equipped with Junkers L2 and Junkers L5 engines
D-403 was equipped with a L2 engine and was used for a long distance flight to Turkey.
The Junkers G24 was equipped with the Junkers L2.
Due to the Allied restrictions upon German aircraft, the G23/G24 was only allowed
to be built with limited engines. The G23 prototype in 1924 got a center L2 engine,
while the wing engines were Daimler DIIa engines with 88kW each.
The initial series G24ba was equipped with three L2 engines.
A total of 19 aircraft with this equipment were built in 1925.
The further improved G24bi got a stronger L5 center engine,
while the wing engines remained as L2 engines.
A single G24bi remained the center L2 engine, but got L5 on the wings.
The G24li also got a center L5 and L2 engines on the wing.
Since 1926 most G24 were equipped with L5 engines or others.
While most of the W33 series were equipped with a Junkers L5 engine.
the W33ba series got the smaller Junkers L2 engine.
Only a few of this type were built and later W33 got the L5.