The Junkers L88 was

Junkers Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded there in Dessau, Germ ...

' first geared V-12 engine, appearing c.1930 and based on a pair of 6-cylinder L8s. In 1932 a supercharger was added. It was used in the first pressurised aircraft, the

Junkers Ju 49 The Junkers Ju 49 was a German aircraft designed to investigate high-altitude flight and the techniques of cabin pressurization. It was the world's second working pressurized aircraft, following the Engineering Division USD-9A which first flew i ...

and, for a while, in the large G 38 airliner and its Japanese built military version.

Design and development

In 1929 Junkers developed their successful

Junkers L5 The Junkers L 5 was a six-cylinder, water-cooled, inline engine for aircraft built in Germany during the 1920s. First run in 1925, it was a much enlarged development of the Junkers L2. Design and development The Junkers L5 was a development of J ...

6-cylinder inline 4-stroke aircraft engine into the L8 by increasing its rotational speed and gearing down the output shaft. Just as the L55 V-12 was made by combining two L5s, the L88 combined two L8s into a 60° V-12. This had the same bore, stroke, camshaft operated twin pairs of valves per cylinder, watercooling etc. as the L5, like the L55 driving a common crankshaft in a revised crankcase. An exhaust driven

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 ...

was added after a year to maintain power at high altitude and this version was named the L88a.Kay

Operational history

Only a few L88 and L88a engines were built. The Ju 49 high altitude research aircraft initially (1932) flew with the L88 and later (1934) with the supercharged L88a. The two G38s used a variety of engines including both the L88 and the L88a. The heavy bomber variant of the G 38, built in Japan as the

Mitsubishi Ki-20 The Mitsubishi Ki-20 is a Japanese bomber variant of the Junkers G.38 airliner. Mitsubishi manufactured six aircraft under license from Junkers. These aircraft, designated Army Type 92 Heavy Bomber, served through the 1930s. During World War II, th ...

was initially powered by L88as. These were replaced, as on the G 38s, by Jumo 204 diesel engines.

Applications

Junkers G 38 The Junkers G.38 was a large German four-engined transport aircraft which first flew in 1929.EADS Two examples were constructed in Germany. Both aircraft flew as a commercial transport within Europe in the years leading up to World War II. Durin ...

, both L 88 and L 88a *

, L88a

Specifications

References

Bibliography