Hello guys,

I have a friend's turbine here that has been sitting in storage for about 2 years, and the bearings are now noisy. they are probably dead, or could this be just from them drying up ?

Does it neccessarily need a bearing change ?

thanks.

Lior,
Could very well be some oil residue that has solidified. Pull off the front cover, pull off the lube line from the nipple and inject some kero directly down the lube line into the engine. Turn the shaft over with some compressed air and repeat a second time, then reassemble. During the first run, let the engine idle for a few min (dont go to full power!) then shut down and see if they smoothed out. If not... probably need to be replaced....

It definitely feels that way as its not 100% smooth when i rotate it by hand. but it used to be smooth before it was stored. i will try your tip - thanks Todd.

The bearings are probably dry from sitting for so long without lubrication.
Stand the engine on its tailcone so it is standing nose up.
Remove the nose cowling and locate the lubrication fitting.
Using a small syringe, and a short length of 4MM tubing, inject about 5 to 10 CC's of turbine oil into the lubrication fitting, and allow the turbine to stand in vertically for a few hours.
By spinning the shaft you should notice the oil in the bearings.
As soon as the oil has gone down the shaft tunnel and filled the reqr bearing, you will notice a difference in the bearings.
I would not run it until after the bearings are lubed.

Now how to ID the lub nipple from the injector nipple? Is it the last from the fuel line or is it[]??.

I have injected 10cc of Mobil Jet Oil into the lube like while spinning the turbine with my hand. some of it dripped out the back through the turbine wheel, but the bearings feel a little better and quiter already (not perfect yet). i will also do Todd's method tommorow after the oil sits overnight as it sounds like a good idea to rinse the dry bearings with Kero and perhaps remove any oil that gummed up on them.

Thanks for the tips guys !

The bearings will clean up faster if you stand the back end of the turbine in a container of kero.

shall i soak the entire back end in kero complete ?

Lior, you need to get some sleep soon! lol
You goodies are on its way to you, Cheers!

Barry

Thank you very much Barry, much appriciated !

I have noticed while playing with this turbine, that when i press the shaft backwards (from the front nut) it feels smoother and when i pull the shaft forward it feels notchier. perhaps there is also a preload issue ?

Either way i have run oil and kero through the lube line and will keep the back soaked in kero all night.

After oiling and sinking the turbine in Kero all night, the turbine is indeed more free to turn, but the rear bearing still feels a bit notchy / noisy.

What do you guys think ? send it out right away or do a test run ?

If the rear bearing is rough, it might not be long for this world. Why take a chance with a possible catastrophic failure?
Years ago, one of my RAM 750's suffered a rear bearing failure which ruined the NGV, turbine wheel, bearings, shaft tunnel, and exhaust nozzle.
Not a cheap repair.

If it was smooth before, then all that has happened is the bearings have gummed up, there cant be anything else wrong with them as the balls are ceramic and the cage/inner cone are stainless steel. The preload spring/spacer could also be sticky due to the dried up oil.

So long as you know your lube line is clear by adding some mixed fuel into the lube pipe with a syringe, if it empty's the syringe then it must be going through, this will flush the front bearing then the tunnel then rear bearing and help free them up.

The bearings will be getting lube when the turbine is run so having a bearing failure is not really an issue, bearings only tend to fail if they run dry. It would be different if the bearings had steel balls and cages and were rusty as what happens on glow engines that are lying for some time.

This all depends on how many hours were on the engine in the first place, if there are 20+ then maybe it should be sent off for a bearing change if not I would fire it up and let it idle for a bit then shut it down again and see what it is like.

This turbine has about 10 hours i think, but the bearings definitely feel notchy (not smooth) by hand so im a little concerned. when i spin it with my hand it does spin freely for a few seconds.
I want to be catious and avoid possible damage. i think i will send it off anyway.