After 2 short taxi tests of my FE F16 I ran a torch up the tail pipe to find just near the bell mouth it has badly distorted/melted due to heat. I am using an Artes Falcon JF 100. Gap is 1 inch.

After close inspection using an incidence meter I note that the turbine is 2 degrees down thrust to the tail pipe. The bad distortion accured at this point.

It is a dual wall pipe.

Is this normal?????? Can just 2 degrees cause this problem??? It is very bad and I will definately need a new pipe.

How do I fix this in the mean time as I have a jet event at Temora in 2 days for the maiden?????????

Cheers,

Mav

Mav,

The problem that you have experienced sounds very unusual indeed. Do you have any pictures that you can post of your install? What are the dimensions of the tail pipe?

Regards

Paul

Paul,

Is 78mm inner and 88mm outer. Turbine is Artes Falcon 100. 1 inch gap?????????

I will try and post a pic.

Mav[8D]

Here is a pic. The photo makes it look a little worse than it is but the distortion as you look at the pic is at the bottom right hand side of the pipe close to the turbine exhaust.???

Can 2 degrees do this????

Mav

I wonder if the pipe it to small for a 23 LB thrust turbine?

its hard to tell in the picture, but it doesn't appear that the turbine was centered to the tailpipe during installation.

The outer pipe should extend past the inner pipe at the rear by 3/8" to 1/2" to create a venturi effect and pull cooling air between the two pipes.

You mention a "one inch gap". I assume you are referring to the gap between the tailcone of the engine, and the front of the inner pipe.
Between what points are you measuring this gap?
It's hard to tell from the picture, but the tailcone of the the turbine you are using looks similar to a P-80 in that it has an inner cone and an outer cone. You should be measuring between the back edge of the outer tailcone and the front of the tailpipe.
If you made the gap between the back of the inner tailcone and the front of the pipe it would be way too wide and allow for the gasses to expand too much before they even entered the tailpipe, and probably create the problems you are seeing.

looks like it it started to collapse on you ..

The engine MUST be centered in the pipe with NO offset thrust( You mention 2 degrees), This is a NO NO, as it WILL cause hot spots in the pipe walls.................Get a new pipe.

Did you have any wetstarts??

That'll also do it.

Raf

LOL….. Terry he said 2 degrees and not 20. AFAIC 2 degrees are not bad. I wonder how many people would notice 2 degree offset with their naked eyes.
FWIW, I think Kevin W is on the right track with his assessment.

Thanks for reply guys.

I sleep when you are awake here is OZ sorry.

Yes 2 degrees measured by incedence meter. I did not think this was much, but if you stare at it long enough you can just see it. I did this to get the correct thrust angle at the exit of the pipe for neutral model thrust FE F16.

It did distort badly in the direction of the 2 degrees however, so this must be part of it. But come on as you say barely visible by the naked eye so I am sure others have plus or minus 2 dgrees.

1 inch from the rear of the outer tail cone of turbine Falcon 100 23 pounds. This is the manufacturers specs 1 inch min to 1 1/4 max gap to bell mouth.

I bot the digital verniers out and get approx .15mm stainless thickness. I am thinking this is too thin for the job or poor quality. I have never heard of anyone else having this issue???

FE are going to send me a replacement if I pay for this shipping. I just hope I do not have the same issue???

I was planning on patching this one so I could at least do the maiden in 2 days. What you think????

Mav[8D]

What about the back end of the tailpipe?
Does the outer pipe extend at least 3/8" past the end of the inner pipe?

If both pipes are even at the back (or worse, if the inner pipe extends past the outer pipe) the assembly will not create a venturi effect like it was intended, and as a result you will not have cool air being pulled between the two pipes.

I would not fly with the pipe you have. You will be nervous enough on the maiden flight without having to worry about your tailpipe collapsing on you, and if it does collapse in the air there is a very good chance that the back of your airplane will be nothing but ashes before it even has a chance to crash.

Wait for a replacement pipe, and don't fly until you are sure it is working properly.

Good call Keith. 1 day to Temora and maiden now and I think I may have a replacment from the dealer who is attending. I will rip out the old pipe and post pics. My problem is I do not really know why this happened in the first place and don't want the same thing to happen to the replacment pipe which will probably be identical. It is the Chinese Fly Eagle F 16 by the way!

Cheers, Mav[8D]

Mavrik, get a new pipe and shim the turbin in the rear with some thiiiinnnnnn ply. If you just shim the aft screws of the mount it should cure the two degrees down thrust. just my opinion on a quick fix to get you airborne. Nick

Hello

Same thing happened to a person that I know here. He has a WREN 54 in his Fly Eagle F-16 and exactly the same happened after the first engine run in the airframe. So maybe they are using poor quality materials for their pipes.

Paul

Paul,

I measured again wit hte digital vernier calipers. It is .1mm thick stainless. Glad to hear someone else is having the same issue!!

I think this is marginal. I leave tomorrow for the maiden. Will hopefully get new pipe from the dealer and place a .2mm stainless shim in about 4 inches wide.

I think the Chinese stainless is just too thin and possibly poor quality.

Where to get a .2mm good quality pipe????

Mav[8D]

www.tamjets.com

Yeap!1 Tamjets.com ...Hands down.

http://www.tamjets.com/original/index.php?cPath=3

I while back I noticed a disgarded stainless steel drink cup dispencer that went on the side of a water cooler at my work. I thought it looked a lot like a tail pipe and might work as one, well it did.., cut to fit, works great, heavy duty, last long time. I will get a pic, and will measure.

I can see it now, the mysterious disappearance of water cooler cup dispensers all over the world.

Actually, it was THREE pipes that were molten like butter. As I have witnessed this meltdown, I think that the material they are using is flimsy and not tough enough to withstand the 600 degrees (on a cool day) of the exhaust gasses.

Chris

There is many different kind of stainless steel grade.
I alway goes with the best material to made the pipe. I had many customers had chinese pipe colapse and had us made them new one.
Spend money on quality pipe it worth every pennies.

I totally agree!!!

Chris

hi,

unfortunately i am the one who melted 3 tailpipes by fej on my fej f16 and yet dont know the reason .as you can see from the pictures taken damage is huge.already thrown 2 of them in the dustbin but i hold the third as damage is less and at the front only and i am thinking of making one ground run with this installed and see what happens.thanks to chris (wren rep in cyprus) he gave me new pump-ecu-and an mw-54 to eliminate possibilities of faulty items.
length of the tailpipe(dualwall) is 58cm without bellmouth.outer pipe extends past inner pipe by 1.5cm .

TAM,if you can make one for me reply to my topic or pm me.

anyone with suggestions as to why this has happened be my guest!!

rgds NIK