Ok that helps a little
Short summary:
Part I:
Basically it is about the development of the BMW IIIa motor. A motor developed for great altitudes. Besides BMW was before called the Rapp motor company. In February when a new chief engeneer Max Friz arrived from Mercedes he wanted to do an overcompressed motor because he wasnt able to do this project at Mercedes (Daimler). This concept was suggested by Wilhelm Maybach a year before (1916) but wasnt realized. On 20 May 1917 Friz registered the first construction draft for the new motor. The engineer based it as a 6 cylinder in-line motor, which would ensure optimal mass compensation and therefore a low vibration level. The overdimensioned Cylinder head and cylinder were constructed as a combined unit to avoid a critical head gasket.
One of the most important components of the innovative engine Friz constructed with a special high-altitude carburetor. A System of 3 mixing chambres, each 3 Air - and fuel injectors as well as 5 throttle valves worked so together that the mixing could be regulated to the specific flight altitude
The pilot had to have two levers for normal or Höhengas. This mix regulation should bring the motor later a very good proportion between performance and consumption. The design drawings were still not quite finished, in July 1917 as a commission of the army visited Rapp-engine plants to discuss the project.
After its construction Friz presented and explained, the military was so convinced that they promptly ordered 600 pieces of the engine.
Through this success several internal restructurings were done within the company and company founder Rapp left the company. On July 21 1917 the company was renamed in Bayerische Motorenwerke.
It was only then when the actual company logo was replaced by the today sitll actual logo with the white blue colors of bavaria. etc etc.
On December 23 1917 first BMW engine withe the designation IIIa took lift off within a Rumpler C.IV. It had 185 PS (hp) and 2500 were ordered by the military. Until war's end not all could be delivered.
Note from Wingman81: Same motor was also in the Fokker D.VII, designated as Fokker D.VII(F). Pilots preferred this motor over the regular Mercedes D.III ones. Later Mercedes made D.IIIaü motor with 200 PSNext part tomorrow
