ORIGINAL: myring
Thanks.
I have assembled it again. The last run seemed better yesterday although start max. temp reached to 800 degrees. I raised the fuel level (it always belowed the engine before and is higher than fuel line inlet) when rotor hung at 31K rmp then rotor dramaticly ran up to idle speed. However the engine still had a aglow and flame tail cone with EGT 760 degrees. I pushed throttle a little after stabilizing for a few seconds and the engine speed increased to 100K rmp while EGT decreased to 620 degrees that eliminated the tail flame. But EGT got back to above 700 degrees and flame came out of tail again when throttle restored to idle.
This phenomenon should be caused by bigger gap between turbine blade tip and NGV shroud, right?
Another thing is whether fuel level should be above the engine fuel line inlet during running.
You said ECU controlling of EGT is right. High EGT makes engine hang start. But why do the fuel level affect engine start?
Your high EGT's at start up could be just having the gas on too long, looking back through the readings I downloaded of my last 51mins the egts are at there highest just as the gas is being turned off at around 25K so watch the display and get the gas off no more than 25K, you only need it on long enough for the turbine to run on kero.
620K seems high at 100K mine would be about 470°c
Have you tried it at full throttle ?
Fuel level should not effect things as the pump controls the flow