In 1937, the engineer M. Chaumont from SMRA (Renault) constructed an inverted V-12 engine in the workshops of CM Béarn. This engine produced 650 hp at 2700 rpm (Model 12B) with limited 5 minute overpower to 850 hp (2800 rpm). It had  gear and supercharger.

-In 1939 they present the 6DO1 that gave 300 CV at 2700 rpm with 6 inverted cylinders. This engine was installed in the Marcel Bloch 800 during the following years.

-The 325 CV 6D03 engine was similar to the one mentioned before, and the 6D07s, which delivered 350/400 CV were installed in the SO-90 Cassiopée and in the SN-20.

-The Béarn engines were initially built by “Constructions Mécaniques du Béarn”, in Jurançon, in the Basses Pyrinees (lower Pyrenees).

"Bearn 12A"

"Bearn 6D, right side view"

"Bearn 6D, left side view"

-The 6D's characteristics were nominal 350 CV at 2,000 rpm, 375 CV with 87 oct. gasoline, 425 CV with 100 oct. gasoline.

-A planetary gear with spur pinions, which reduces 2/3.

-The Bearn engines were also built by SCEMM ó "Société pour la Construction et Exploitation de Materiels et Moteurs". Some publications mention this company incorrectly as SE.

-Another engine was the 12B, a 12-cylinder inverted V-engine that produced 1,000 CV.

"Bearn 12B"

"Bearn 12A"

-The 12A delivered 400 CV. This was an original for being an I engine, a vertical upright-cylinder line attached to another inverted one.