Kurt Tank's design team prepared two proposals; one based upon the use of the Daimler-Benz DB601 liquid-cooled engine and the other upon the use of the BMW 801 air-cooled radial engine. At that time the radial engine was not favored as a fighter power plant owing to its drag and the restrictions that its bulk placed upon forward view during taking-off and landing, and, in consequence, General Ernst Udet's decision to proceed with the development of the radial-engined fighter came as a profound surprise to Tank and his colleagues.

Test pilots had objected to proximity of the engine to the cockpit which resulted in extremely high cabin temperatures, sometimes reaching 55øC. (131øF.), which, as Sander said, felt as though he had his "feet in the fireplace."

In addition, exhaust gases found their way into the cockpit and necessitated the continuous use of an oxygen mask. Therefore in the next prototypes the cockpit was relocated further aft, a move also suggested by the c.g. problems presented by the heavier engine.

By the end of the war, more than 20,000 Fw 190s had been built; about one-third as fighter bombers. A nice figure if you consider the plane was a second "iron in the fire" as it was referred to when the first order in 1937 was placed.

More:

http://www.aviation-history.com/focke-wulf/fw190.html

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