The Jumo 207 was a futher developement of the Jumo 205 for high altitude missions. The developement was started in 1939. Compared to the Jumo 205 the new engine got two inline centrifugal superchargers and a precooler. The first of these superchargers was driven by the exhaust turbine. Cylinders and internal dimensions were the same as with the Jumo 205.
Four different subtypes were developed, Jumo 207A to D The initial series A-0 was first flown within a high altitude Ju86P in 1940. On September 17th 1940 the prototype reached an altitude of 10000 meters with a Jumo 207A for the first time. Difficulties during flight tests led to the serial versions A-1 and A-2. The A-series had an airscrew drive of 0,632
Rear View of a Jumo 207-B3
The B-series had an airscrew drive of 0,602. The B-1 was not built. B-2 was the basic B-series model while B-3 got a larger supercharger and a GM1-injection. The Jumo 207B was used in the improved Ju86R since 1942 and allowed an operating altitude of 12000 meters for survey missions.
The C-series were designed for short maximum power while the D-series got a larger bore. Both engines became available in 1944 and probably some were used for test proposes in some aircraft, however they were never used for offical missions.
Aircraft Types equipped with Jumo 207:
Junkers Ju86 P and R
It was originally a Ju86G, which changed it BMW132 to a Jumo 207.
During test flights with the new engine, V28 crashed while flying in large altitudes.
This crash was caused by reduced power during gliding
causing the ignition to fail above a flight altitude of 4000 meters.
The high altitude surveyer Ju86P2 and P3 also used the Jumo 207A-1.
The further improved Ju86R-1 and R-2 high altitude surveyers
were equipped with Jumo 207B-3 engines. Only a few were built.
The Ju86R-3 was a projected Jumo 208 driven Ju86. It was not built.
Blohm & Voss BV222 C-0
The passenger flying boat BV222 was originally equipped with 6 Bramo 323 R-2.
The later BV222 C-0 series instead got the Jumo 207C engine.
The first BV222 with this engine was V7. Only a few were built.
It also seems that some engines were used on the Junkers Ju 252
Further reading at other Sites:
unknown (scroll down for Jumo 207 description)