I lose power/performance from a 6L 40/45 600rpm MAN engine. After T/C overhaul the engine runs at full performance for about 1500 - 2000 hrs and then drops off so the CPP pitch limit drops from 16.5 to 11-12 by about 4000 hrs. The limit is caused by exhaust temp limits of 480 deg C. The T/C is...