How reliable are WWII turbochargers? Does adding them to an otherwise reliable engine, e.g. the P&W Double Wasp and the Allison, decreases the overall reliability of the engine? Are they well made enough to sustain the head of the exhaust (my guess from rough calculations under the presumption of adiabatic combustion puts it in the 800K-1200K range) without creeping?Are they well made enough to sustain the heat of the exhaust (my guess from rough calculations under the presumption of adiabatic combustion puts it in the 800K-1200K range) without creeping? My impression is superalloys are not around until about 1950s.
Is the relative unreliability of the turbochargers (turbine wheel to be exact) the reason why the great majority of high-performance WWII engines opted for supercharging as supercharger operates in the cold end of the engine only?