The Hs 129 idea done 'right', and for everyone

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Gotcha - I'm not all too familiar with the 139, just that the project was merged with Bramo's 323 for the 801 development.
I recall overheating issues with the 139's installation in the early Fw190 prototypes, but that was mainly attributed to the cowling design at the time.
 

BMW 139 have had all three bearings between the crank throws - yes, no usual front and end bearings as one can expect it on a radial engine. We sometimes criticize the German engineers of being too smart for their own good, and this was one such example.
The 801 was a wholesale redesign of the 139, with front, central and end bearing on the places one will expect to find them, and unsurprisingly that layout worked. Weight penalty was steep, some 25% extra vs. the 139.

(there was a lot of work for the 801 to be made to work between 1940 and 42, between the impellers cracking/breaking especially due to the FOD, improvements to the oil system, indeed the all-around better cooling of the engine, material for the valves+ coating...)
 

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