F86_SABRE

Hi Gerald,
I did strip down a turbine as the compressor slightly touched the front cover. I opened it up and replaced the compressor wheel and changed bearings at the same time. I did not have a balancer and I still had to send it away as I had no balancer. So it is ok if one is doing a bearing change but what about if one has to change compressor or turbine wheel?

Reuben

siddus74

Reuben,

What turbine did you have that required bearings and the compressor touching the front cover? Did the bearing change cure the problem of the touching?

Scott.

luckyy

My Feedback: (2)

Does sand ingestion kill the bearings??

F86_SABRE

Since the turbine was disassembled I decided that I might as well change the bearings. I had originally decided to open the turbine when I heard a noise coming from the front end of the turbine. It then resulted that the compressor just skimmed the cover. Infact, I found minute bits of aluminum behind the compressor wheel and could also see that the compressor had shiny parts. It was only then that I decided to change compressor wheel and bearings...nothing serious. The turbine worked well afterwards after it was sent for balancing and assembling again.

Reuben

Gerald Rutten

The non-balancing method only applies for bearings. When a major component like turbine wheel, compressor or shaft is replaced you realy need to balance it or have someone do it for you. A compressor which has touched the casing slightly can be repaired very easy and does not need a new compressor, just sand the touched faces with sandpaper #80 and than with scotchbrite (They do this in full-size engines as well!!) but also in this case it needs balancing.

Best regards,
Gerald

Below one of my homebuilts, a 120N engine which had touched very slightly. In this case I cleaned it with sandpaper and even did not balance it, no sweath, the engine run's now for several years with the same bearings.

basimpsn

My Feedback: (5)

Very nice work Gerald, Question about your RPM sensor, have you ever experience any RPM malfunction when your engine is expose to direct sunlight?

Gerald Rutten

No, not on the testbech but I havo no experience with external positioned engines. All my engines are contained within the model so that wil not have any effect on the sensor. A few years ago I changed over to FADEC ecu's with magnet/hall sensor, have only one optical sensor engine which is currently in my Avonds F15.

Rgds,
Gerald

basimpsn

My Feedback: (5)

Got it

siddus74

Heres my attempt at a P80 Repair ... [link=http://www.rcuniverse.com/forum/m_10768031/tm.htm]Jetcat P80 Strip[/link]

Scott.

The Bush

Jet Cat Parts !!! Can you buy spares ?

I have a JETCAT 120 SE i want to repair it myself.

I have built a couple of motors in the past and have a work shop.

Do you know where i can get spare parts ?

I emailed Jet Cat – they would not answer my questions, just told me to send the motor back for repair !!

I need:
1. Starter assembly
2. Front Cover
3. Compressor
4. Outer cover

Thanks Bush

Xairflyer

My Feedback: (1)

I see Ali has the starter on his website, there is a post somewhere for the turbo part number for the compressor, but as far as I know it needs a little machining to fit.

mitchilito

My Feedback: (7)

Wasn't happy with the way my JC Titan 160 was acting on acceleration. I assumed the fuel manifold was clogged (or some such) so I I tore it down today. It has 26 hours on it so I figured I'd do a bearing change while I'm at it. The interesting thing is, I didn't find anything wrong with any of the internals that would contribute to accel instability. What I did find, unfortunately, is a cracked Nozzle Guide Vane assembly. Wonder if I can get a replacement from JC. . . .

Look at the NGV pictures and you'll see the crack. It's pretty bad. Only a matter of time before it would've destroyed the engine (and maybe the aircraft).

Xairflyer

My Feedback: (1)

If you cant get one from JC you might be able to get it welded by a good TIG welder with a 625 rod.

donnyman

MITCHILITO

Been looking at your ngv from what I can see is you have and uneven high temp condition across your ngv. the red rusted areas looks to be caused by flame impingement. and improperly located at that. (combustion flame touching the ngv) I wont say how this can be corrected because I have not worked on that engine and don't suggest you do. If it were mine I would see about making some serious changes.

the situation you have is why experience is needed, you may well get it back together and it may run fine for a while but........
I think you would be wise to return that unit to the manufacturer IMHO it needs serious work.

Good luck...........Donny

mitchilito

My Feedback: (7)

I fly this jet mostly off of a grass field and frankly, it eats a bunch of grass/dandy lions etc. I'm assuming that is what you're seeing on the NGV. I say this because the rest of the internals are in perfect condition. Compressor's in great shape, the vaporizers are flowing fine (see pic) etc. I can't see anything that would be causing a problem. Not sure of the history of this engine but I suspect it pretty high time.

I'm not worried about it at all - if I can get a replacement NGV.

Dr Honda

My Feedback: (4)

Yep... what he said. it can be TIG'ed.

Heck... where it's at... I would clean it... and just use the TIG to fuse it back together. (no rod needed)

Keron232

I need a titan nav to buy used anybody have any

jetrichie

reposting for future users link to JJ1400/wren 54 rebuild as not working above

JJ1400 14lb Turbine Stripdown/Rebuild