Out of the V-12 that were in production (so no prototypes, nor one-offs, but at least 500 produced) in 1941, what one should be considered as the best? The contender need to have plenty of power, both for take off and at altitude, while being of decent reliability (meaning it's really powering planes in flight), and suitable for the mass production. Weight size do matter, a lighter smaller engine for the same power has the edge. In case you thin that a special feature of an engine should adds 'points', please post about that. You can also state your champion and a runner up, making sure that you elaborate your choices.