BMW 801 production engineering

[Jukka Juutinen]

According to some information BMW was able to drastically reduce the manhours needed in 801 production by automatization of production. Any more information on this?

[jschreiber]

Hello

The primary source for that comes from an internal BMW document "BMW. Ausbau der Werksanlagen und Anlauf der Lieferungen", probably from early 1945, and preserved at Bundes Archiv Koblenz. Manhours sank from about 3 000 (1940) to 1250 (1944), with also a drastic reduction of raw materials needed.

However, the "reference book" on german aero engines (Deutsche Luftfahrt, Kolbenmotoren and Strahltriebwerke, K von Gestorff and others) states that the BMW 801 needed in the mean 2 000 hours to be built, plus time needed for the fuel injection pump and the compressor. Since one of the designers of the BMW 801 was one of the autors of this book, this value make some sense. Moreover, the same primary source is also cited.

From my humble point of view, since BMW had very strong ties with the NS party, one could be cautious with internal reports "for the outside world"... That said, 2 000 hours is not a bad value for such a large engine (the DB 601/605 needed 2 500 to 3 000 hours). We have not to forget that about one half of those engines were manufactured outside the BMW main plants, and needed more time to be built. So the 1 250 hours figure could be the "best case" value, and had to be put in front for the political masters.

From a technical point of view, according "Kolbenmotoren und Strahltriebwerke", parts were simplified, manufactured with faster processes (less forging), better and more jigs, and line work was maximized in the assembly process. All that engineering effort has is own cost, obviously not included in the 1 250 hours figure.

Regards
J Schreiber