Reliability and longevity.

Getting more power out of an engine than it was designed to produce means more wear and tear on the engine. The OM617 wasn't designed to produce those power levels, it was pushed there. For example, I'm sure they ran much more boost than normal. This would increase wear on the rings and bearings.

I'm sure that the C-111 was more than just a record attempt and publicity stunt. In engineering its not unusual to push a design beyond its designed operating parameters for an extended period to see where it breaks before the design goes into production. This way weakness can be identified and corrected before it becomes a major problem.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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