ira d

My P80 SN 1327 has started to make a roaring noise at about 80K rpm and gets louder as the rpm increases. It does not appear to be a rubbing sound but more like a wind sound and the engine spools
up and down like normal.

On my last run I did at home I ran it up 113K with a max PV of 2.45, the start temp was 683 and max temp was 801 with a min temp of 526, the engine has 9 hr run time since last service.

AlanRockey

Bearings

ira d

I don’t know anything could be possible but its only been 9hr run time on new bearings and the engine is smooth to turn by hand and does not seem to slow down after shut down any quicker than before.

The time before when it had bad bearing you could hear and feel them just by spinning the engine by hand. I talked to JetCat Germany today and they are concerned about the high EGT temps I have
been getting even before the noise started.

Thanks for the reply.

Dave Wilshere

Combustion chamber could be breaking down.

AlanRockey

Keep us informed of the outcome please.
I have a few other questions if you have time.
What is the total time since new?
When was last good run?
Have you changed the fuel type or oil type recently?
Thanks!

ira d

I am not sure of the total run time since new as I failed to record the time before sending in for service and JetCat always resets the time when they service the engine. Even though I have the engine about thirteen years
the total time I would estimate to be around 25-30 hours. I last flew with engine 3 days ago the first flight was fine but started making the noise on the second flight although the performance seemed the same.

I have not changed fuel recently I am using kero with DTE light 5% and I have at times used Aero Shell turbine oil also. Looking at the age of the engine I am not sure if I want to spend much to repair it or sale it cheap
and move to a newer engine, maybe its worth something for parts if someone has one like it.

ira d

I am kind of thinking that also. Do you have a idea what a new chamber would cost and are they still readily available.

mr_matt

My Feedback: (10)

Hi Ira,

Does not sounds consistent with bearing noises I am familiar with. Sounds like some sort of combustion issue. I have had things change when an injector tube eroded and broke, or even when FOD got in and damaged the diffuser vanes (that was an old old P-80) Some designs are very sensitive.

Jetkopter

My Feedback: (1)

I agree with Matt, Could be eroded nozzle in the combustion chamber, Did you happen to look at the nozzle and turbine wheel when its running to see if there is a hotspot in the chamber?

mr_matt

My Feedback: (10)

I remember, when an old P-80 would go wonky, it was hard to start but then it would run and stay running.

A P-120 goes wonky and it would start fine then quit accelerating down the runway :-)

Or maybe I got that backwards........

ira d

No maybe I will try that.

ira d

My engine starts and runs fine just has the weird noise at upper RPM’s.

mr_matt

My Feedback: (10)

I would buy a new motor and save it as a spare for a far away jet event, just in case.

ira d

Being that the P80 is a large motor by todays standards I doubt I will have a plane that I could install it in down the road after I move to a new motor, I will give it some thought I will either fix it are sell it as is either way
there is not a large market for a P80 nowadays and depending on what it would take to repair it I might not even break even selling it after repairing it. I will not be flying the motor again before it’s fixed either it may do
fine for a while or it may not.

Felix Barrao

Check if the turbine wheel has rubbed with the NGV . This NGV itīs made from two pieces, ( the vanes part, and the ring that covers the turbine wheel). This two pieces are welded and sometimes fails. ( I have seen three of them) The engine works, but at high rpm the outer ring vibrates and rub the turbine wheel. Itīs easy to verify checking by the rear side,