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BMW 139:
1500 HP @ 2700 rpm
800 kg without additional equipment
1940 BMW801 prototype
1,539 hp
1,088 kg.
DB603A V12 engine
1,750 hp
920 kg.
Why was BMW so enamored with air cooled engines? From the mid 1920s until the mid 1930s the BMW VI V12 dominated the German aircraft engine market. You would think they would use their experience with V12s to produce a modern V12 to compete with the 1,750 hp DB603 engine.
The 1930 RLM specifications called for a 35 liter engine. During the early 1930s BMW had more experience with V12s then either Junkers or Daimler-Benz. Why didn't BMW compete for the new V12 contract?
That engine was just as obsolete as the BMW VI V12. Obtaining enough hp to compete with a modern water cooled V12 required a twin radial and that is a very different animal.Why not start with the 1926-7 P&W Hornet they were making
That engine was just as obsolete as the BMW VI V12. Obtaining enough hp to compete with a modern water cooled V12 required a twin radial and that is a very different animal.
If BMW had obtained a license for the 30 liter P&W R-1830 twin radial it would be a different story. It was as powerful as early models of the DB600 engine yet weighed less. Tweek it a bit and you get something like the P&W R-2000 twin radial which produced 1,300 hp fueled by 87 octane gasoline.
According to Pratt Whitney the R1830 entered production during 1932. 4 years before Daimler-Benz began building the first DB600 engine factory at Genshagen and 5 years before the DB600 engine entered mass production. I think BMW could have a variant of the R1830 in license production before the first DB600 engine rolls off the Genshagen assembly line. With a single speed supercharger and fuel injection the BMW R1830 ought to be good for 1,000 hp. As much as the DB600A engine. It would use the same production facilities as the historical BMW132 single radial engine.