Gnome-Rhone 14N

In 1936 the 14K-series was replaced by the Gnome-Rhône 14N delivering 1,100 hp from a
slightly heavier engine that nevertheless had a much better power-to-weight ratio.
Starting with the N they introduced a new naming scheme, replacing the earlier model
letters with numbers, delivering the engine in versions that turned left with even
numbers and right with odd. The original 14N-0/1 was run through a number of versions,
the 14N-10/11 seeing use on the Bloch MB.210 bomber, the 14N-25 on the Bloch MB.152
fighter, and the 14N-49 intended the updated MB.155 which did not see action. The
N-series finally ended with the 14N-50/51, which delivered 1,210hp for takeoff.
The 14N was not as widely licensed, as the war was approaching and the French government
was becoming increasingly wary of licensing designs to potential enemies.

The 14N-series was itself replaced by the ultimate pre-war evolution of the line, the
Gnome-Rhône 14R. The first versions introduced in 1939, the 14R-4/5, produced 1,291 hp
for takeoff and was only slightly heavier than the 14N. By 1940 the improved 14R-8/9 was
delivering 1,578 hp by increasing RPM from 2,400 to 2,600. Although this was a good figure
for the era, British and German design had already passed this mark, and would soon be
pressing on 2,000hp.

With the fall of France in 1940, Gnome et Rhône was ordered to produce the BMW 801 under
license, while the 14M saw limited use on some German designs. The company became infamous
for slow production, building only 8,500 engines by May 1944, when the Germans had been
estimating 25,000. That month a massive US air raid completely destroyed the original
Gennevilliers factories.

With the end of the war, the company was in no condition to continue in the aero-engine
business, although they picked up small contracts to produce M4 Sherman tanks for the
French army. In order to save what was left, the company was nationalized on May 29, 1945,
creating the Société Nationale d'Etude et de Construction de Moteurs d'Aviation, or snecma.
In snecma the company would again start production of the 14N, 14R and the new 14U.

Licensed versions and developments
The 14K was one of the most popular engines of its era, widely licensed and used around
the world. In Poland it was used for export fighter variants, most notable PZL P.24. In
particular it was used in Romania, where it powered a number of Polish designed PZL
fighters before finally becoming the main engine of the little-known but interesting
IAR 80 fighter.

Isotta Fraschini and Piaggio of Italy both took out licenses, the former producing the
K.14, the later the P.XI. These were used on a number of designs in the pre-war period,
many of which were exported. This led to Manfred Weiss taking out a license in Hungary,
producing it as the WM K-14 in order to power their versions of the Reggiane Re 2000
fighter.

A particularly important licensee was Nakajima, who produced it as the Sakae. The Sakae
was one of the most popular Japanese engines, powering the Mitsubishi Zero fighter as
well as other designs.