600 Who can recognize what noise that is

[coolgabsi]

You'll hear a metallic noise from the engine. And you'll see the tail give a bit everytime it happens. What is that noise ..? I am trying to
Figure it out.. Lets c if y'all can help

I m Confused

Vibe 55 noise? - YouTube

No vibration... Atleast what I could see

This has just started

Fly safe!! have fun!

 

[heli-maniac]

i would bee looking at the OWB

 

[coolgabsi]

Highly unlikely.. Ill check it ... But:.. It's rock solid... I see why You would think that though

Why I say it isn't.. My tail would have given out way more when I was putting load to it when flying.. Would have Lost power for sure..

That is why I flew it around .. One to clear the engine.. Abd second to show its flying under load..

Fly safe!! have fun!

 

[Lee]

Weird. Not knowing anything about Nitro, i couldn't tell you.

 

[breeze400]

Clutch may be going?

 

[coolgabsi]

well.. may be.. I'll check that.. I am thinking i will have to unmount the engine for this. I got the bird with me today.. I will richen the engine a bit and see if it goes away..

Clutch is very tightly engaged at this time... you could be right.. any other thoughts?

 

[breeze400]

It just sounds to me like ringing of a bell so clutch is what I'm thinking.

 

[coolgabsi]

see thats what I was trying to confirm.. usually.. NOW I SAY usually.. ringing of any kind .. sounding like a metal can or something ends up being the rear bearings. or the engine running too lean.

Thats why today.. I am going to run it again.. richen it up and hear for this noise. If i hear it I will disassemble the engine and change the bearings and check the clutch assembly.

 

[Stambo]

It certainly sounds like some sort of bearing to me. Have you ever spun up a small bearing on a stick with air.
Ok I don't mean helicopter small but something small automotive like an alternator bearing with no lube in it.
(I am an auto tech) As an apprentice we would do this and then let them go zooming across the floor into a concrete wall to see them fly apart. Some would make a similar noise at high rpm until you put a drop of oil in them.
They would also slow down quite dramatically.
I may be way off the mark but just a thought.

 

[coolgabsi]

I couldn't run it today. Some nitro experts are leaning towards a lean engine which in turn also means less lubrication to the bearings also.

So I do think if it doesn't go away with richened engine it'll be the bearing. Then we can use my video as a bench mark to hearing for lean engine or failed bearings lol

Once I get a flight on it. Hopefully tomorrow now... Ill update y'all .

Fly safe!! have fun!

 

[pvolcko]

I was thinking bearing. My vacuum cleaner made a similar noise last night for a minute before the top motor bearing seized.

 

[Tony]

bearing is what I'm thinking as well. Like the cage has broke and the balls start knocking together. If it's a rear bearing in the engine, I would not run it again. But, with the backplate facing down, you should be able to pull it off and have a look at the bearing. If you see metal shavings, then you found it. I would also check the bearings holding the clutch to the frame as well.

 

[coolgabsi]

Now bearings I replaced.. Both were great cindition!!

But did find fuel exhaust leak at the muffler pressure port.. the one thing I hadn't checked. Forum runner not letting me upload.. But if it did y'all probably could tell easily

Fly safe!! have fun!

 

[Tony]

Just go to safari and upload the pictures that way. I don't know what is wrong with forum runner. And can't get no help from vBulletin. since they sold out, the CS has went down teh drain. I'm about to remove it and just have people use the mobile browser that is built into the forum.

 

[Westy]

hmmm .... that muffler leak would maybe cause a fuel pressure drop causing the engine to lean out (just a theory)..... I would suspect an engine bearing or clutch bearing ..... you can see if load up when it binds.

Strip it down till you find it or you will just end up causing more damage. How hot is the engine? do you have an infrared temp gun?

I am certainly not a nitro expert ... but I have worked on a lot of engines and also 2 stroke dirt bikes..... and as soon as you get a gasket leak .... on either side .... your performance and mixture changes drastically as it relies on the scavenging ability of the piston to pump the exhaust gasses all out or it doe snot get a clean burn.

Anyway ... enough of my pratling on! let us know what you find?

 

[coolgabsi]

Replaced the bearing. I was in there I was like ... It doesn't happen that often... I kept the old bearings... The engine insides were immaculate. No heat damage ... The piston ring and sleeve were smooth ... Sleeve didn't need forcing... Just dropped out by itself... No heat nothing.. Lol

I wasn't running on tune on the heli. I never do so I should not have leaned out. But i was..

And yes loss of muffler pressure means loss of fuel going into the tank and then also means loss of back pressure from the muffler to the ports as the muffler pressure nipple sits right on top of the muffler where it meets the engine

I will give it a whirl today and see what changed.

I will update y'all.

Fly safe!! have fun!

 

[coolgabsi]

OK .. my engine is OS55hz, Muffler is Funtech B320.

I had heard about the Funtech pipes being notorious about having the bolts come loose without nylocks. A friend actually took the threads out for me, so I could install a gasket on the port, and then nylocks holding the muffler.

Now the BOTTOM muffler bolt seems to be melting. Its a brand new nut, I changed the engine bearings, and I saw no sign of lean engine per say, but I replaced the prevously molten bolt.

SO new bolt and one tank and its already crowned. Its got white stuff crowned up on top ..(hopefully you can tell in the pic) .. I flew it, came down, retightened everything.. still I wanna be sure that it wont come loose on me.

Second thing:

Muffler pressure nipple seems to be a source of all the leaks I am seeing on the muffler. At first I thought it was from the muffler port, and tried to retighten that.. but they were tight as could be, and the align gasket was still there in the middle.

Now I took the one it had out, and put one from my Funtech 395 on this. It seemed to still have a leak around it, and just like the other stains, it was travelling down with a similar size drop.

My issue is .. HZ engine needs the muffler pressure.. I dont want to burn this engine. .So need advice.. I am thinking metal to metal gasket (silver blue loctite stuff) around it and threading it back in, and letting it sit.. so it would seal it?????????????? Sound ok ? or no?

are there qualities of nylocks ? I had this from I think a a traxxas pack of nylocks. Is there a specific type I am looking for. I have never before seen a molten nylock on the nuts... but here I am ..
??????

 

[Westy]

hey Gabbsy!

Ok ... you could try star washers which will stop vibration loosening

you could also use this type of lock nut .... commonly found on exhaust systems the Best option in my opinion....

you can also make a lock tab plate to lock them down .... Like on truck exhaust manifold, helicopter engine components (they also use lock wire). it has 2 tabs on it that you bend up/down to lock the nut.

For the Gasket on the manifold you can use High Temp Locktite Gasket cement 5910 (+329ºC rated)

For the Thread on the pressure nipple.... you could use Locktite 567

.... or you could also use (depending on how much thread is present) a copper crush washer or fibre washer to seal in the oil and gases.

NOTE: I have extensively used both Locktite Products in high temp applications such as Turbo charger fittings which get Glowing orange hot..... I had photos of some of the 500 - 2000 HP engines we used to run on the Dyno at Cummins.... GLOWING BRIGHT ORANGE!