I continued disassembling the engine tonight hoping to find any clue why the engine has been running so hot lately. Even if the 1000°C interstage temps were a local hot spot it still feels like something has happened.
The turbine wheel looks very nice, sharp wing tips so no signs of overheating!
The power turbine NGV looked a bit worse for wear, as I wrote yesterday five of the vane welds are cracked and one of the vanes was dangerously close to the C20 turbine wheel...
Some minor damage to the compressor inducer wings tells me that something has been sucked into the engine since the last time I took it apart, lets find out if there is more FOD deeper inside the engine shall we?
I didn´t have to dig far to find more damage, three of the diffusor wedges had their leading edges damaged like the one in the picture. This would surely upset the air flow and in the end cause some rise in exhaust temperature. How much I don´t know but most likely measurable.
The last picture for the day is the turbine wheel, oil leaking past the turbine shaft seal has stuck to the rear of the wheel and the shaft has some bluening from the lack of post run cooling. If I run the oil pump after a run a small leak from the freepower shaft cause a fire in the exhaust so I can´t cool it that way for any longer periods.
Cheers!
/Anders