millsy14

I just had what appeared to be a turbine lockup on my P100-RX. I have run the engine 5 times, with two successful flights in a Skymaster Viperjet. I went to run the engine today as a preflight check for some flying tomorrow, and during what seemed to be a normal start, the turbine abruptly stopped. I quickly looked up the tail pipe and could see flames inside engine, so hit it with an extinguisher. It sounded to me like the tubine had seized. I checked the EGT, which was at 170deg C and the ECU did a cool down cyle, which actually spun the engine over. I removed the engine, and could see that there appears to be rubbing on one side of the turbine casing in the vicinity of the turbine blade tips. The data terminal info for the last run was as follows:

Start Fail- accel. slow
Max rpm 18300
Max EGT 685

The engine spins over fine now, What should I do? Are there any known issues with the 100RX and turbine rub?
I bought the engine thru AKModelsport and have just contacted him. Problem is that he is in Germany and Im in Australia. Is there any quick fix, which Im guessing would be no.

Regards Ian.

Darrel Patterso

Hi, I'm no familiar with the Jetcat but had a similar problem with my Wren super sport. The problem was too much gas causing the egt to rise quickly which seem to distort the ngv and cause it to nip the turbine wheel. I simply reduced the gas flow and the problem went away. Hope this helps.

Cheers
Darrel

smitty1001

My Feedback: (29)

Agreed, exact problem on my first motor, a P-80. Seeing how this 100 is almost certainly kero start - probably not quite as easy a fix as lowering the gas. Definitely seek advice from Jetcat service - probably has to go in.

millsy14

Thanks for advice, yes its a kero start, and thinking that it due to low airflow on start with high temps, causing the turbine disc to expand more than the surrounding case. Will wait for jetcat advice for sure. The ambient temp here is also low, probably making the scenario worse. Very frustrating

millsy14

Further info regarding setup. I am running a 2cell lipo as I havnt a charger for the supplied li-fe batt, but did set the Ecu for the 7.4 volt pack. It's a new 20s 4400mah pack. The only thing I changed on the model since I last ran the engine was fitted an additional fuel tank, which the whole system vents from, running 4mm fuel line throughout. Wondering if slow/hung start due to starter battery or restricted fuel supply, may have caused it?

millsy14

Under advice from Udo Toepfer, Jetcat Germany, I gave the engine a run.

I aborted the first start attempt as i could see an uneven burn pattern in the taiI pipe. The engine did lock up again after the aborted start, but understand that could be caused by the uneven heat at that stage of the start. I rang a collegue who advised that the lightoff on one side was normal. I then attemped a start again which was good. The accel delay did stay active for quite a while but it eventually got there. As I was at home, I only gave it some short bursts of acceleration and full power, which seemed normal. I will give it a good run down at our club and see how we go, fingers crossed.

Thanks to Jetcat Germany for prompt response and support, cheers.