With all my references, I still can’t tell what color, so to speak, the actual engine is or what it’s made of. Any ideas?
Andy
My best explanation for that odd blueish hue you see is a sealer called wasserell over a natural cast metal. German powerplants came in Black, RLM grey(A light greenish grey.)RLM black grey and natural. Yet if left unprotected cast iron even a manganese alloy will rust over, so wasserell!. Over the years the sealent fogs & ages acquiring that blue cast. This assumes you are speaking of the motor from a ta 152 that presently is under restoration.