TT H39 Engine (Wah) (Tail wagging again)

[James]

Mornin all.

So I was out at the field the other day, was my first time at any
field with a mate of mine from work. As soon as I started up my
chopper, he said, !QUOT!Geez that engines running rough!QUOT!. So I
let him tune it for me. I must admit that it sounded super sweet after
he had tuned it and almost all of the vibration I had, had disappeared
entirely. Only problem is that the tail started wagging again.

Geez I hate that wagging tail, its so unnecessary!

So last night, I read up a little here and there including on
Raptortechnique. I dropped my engine out, checked that the Bell is
good and true which it was, check the liner, yes it was good, check
the shoe thing thats on top of the fan thing on the engine thats seems
ok too. Now what else should I check I thought, well lets just go over
everything, this, that, this, that, everything seems ok, but the tail
belt seems to me like it might be just a tad too tight, so I slacken
it and then of course its too loose, after a couple of adjustments I
was happy with the tension.

Right! So the engine is still out, so I decide to remove the backplate
to see if everything in there looked good, nice and shiny inside, WOW
that looks nice and smooth.... ahh look there are some bearing, turn
the motor a few turns, yup they look good!

OK, Backplate back on, time to take of the head, of course this is the
first time I am taking this engine apart, I undo the head bolts, they
seemed a little loose, but hey I will tighten those up nicely when I
put the head back on so no big deal.

I look at the top of the piston in utter dis-belief! I reckon, lord
that looks ugly, black and not very nice looking at all and if I
recall my OS .15 max motor's piston still looked shiny and new and
that had about the same amount of fuel through it. Taking a closer
look at the piston I notice that there is actually a little bit
missing from it on the exhaust outlet side. So I have ordered a new
piston and ring.


AND NOW FOR THE QUESTION!

Do you guys have nice shiny pistons at the top or are all of yours
black and sootie looking like mine?

Simple question I know, but hey worth the story! :)

[Bjarte Indrebø]

Depends on what fuel you use. If you use fuel with castoroil, the top of the
piston will be black and sootie. If you use fuel with only syntecic oil, the
piston should be clean and shiny.

Bjarte
Norway
"James" <system@icon.co.za> skrev i melding
news:cc1dcce5.0405010858.5931d16@posting.google.co m...
> Mornin all.
>
> So I was out at the field the other day, was my first time at any
> field with a mate of mine from work. As soon as I started up my
> chopper, he said, !QUOT!Geez that engines running rough!QUOT!. So I
> let him tune it for me. I must admit that it sounded super sweet after
> he had tuned it and almost all of the vibration I had, had disappeared
> entirely. Only problem is that the tail started wagging again.
>
> Geez I hate that wagging tail, its so unnecessary!
>
> So last night, I read up a little here and there including on
> Raptortechnique. I dropped my engine out, checked that the Bell is
> good and true which it was, check the liner, yes it was good, check
> the shoe thing thats on top of the fan thing on the engine thats seems
> ok too. Now what else should I check I thought, well lets just go over
> everything, this, that, this, that, everything seems ok, but the tail
> belt seems to me like it might be just a tad too tight, so I slacken
> it and then of course its too loose, after a couple of adjustments I
> was happy with the tension.
>
> Right! So the engine is still out, so I decide to remove the backplate
> to see if everything in there looked good, nice and shiny inside, WOW
> that looks nice and smooth.... ahh look there are some bearing, turn
> the motor a few turns, yup they look good!
>
> OK, Backplate back on, time to take of the head, of course this is the
> first time I am taking this engine apart, I undo the head bolts, they
> seemed a little loose, but hey I will tighten those up nicely when I
> put the head back on so no big deal.
>
> I look at the top of the piston in utter dis-belief! I reckon, lord
> that looks ugly, black and not very nice looking at all and if I
> recall my OS .15 max motor's piston still looked shiny and new and
> that had about the same amount of fuel through it. Taking a closer
> look at the piston I notice that there is actually a little bit
> missing from it on the exhaust outlet side. So I have ordered a new
> piston and ring.
>
>
> AND NOW FOR THE QUESTION!
>
> Do you guys have nice shiny pistons at the top or are all of yours
> black and sootie looking like mine?
>
> Simple question I know, but hey worth the story! :)

[Paul McIntosh]

Heli engines are going to run a little hotter and if you keep them tuned for
performance, you will get some carbon on top of the piston. Keep it just a
little richer and the buildup won't be so bad. Oils with castor in them
will tend to deposit more carbon than fully synthetic oils.

Unless the carbon gets so thick that you get detonation or hot spots, don't
worry about it. If you want to clean it off, use some ScotchBrite pads. Go
until you can see the metal through the brown. It doesn't have to be shiny
clean.

--
Paul McIntosh
http://www.rc-bearings.com
"James" <system@icon.co.za> wrote in message
news:cc1dcce5.0405010858.5931d16@posting.google.co m...
> Mornin all.
>
> So I was out at the field the other day, was my first time at any
> field with a mate of mine from work. As soon as I started up my
> chopper, he said, !QUOT!Geez that engines running rough!QUOT!. So I
> let him tune it for me. I must admit that it sounded super sweet after
> he had tuned it and almost all of the vibration I had, had disappeared
> entirely. Only problem is that the tail started wagging again.
>
> Geez I hate that wagging tail, its so unnecessary!
>
> So last night, I read up a little here and there including on
> Raptortechnique. I dropped my engine out, checked that the Bell is
> good and true which it was, check the liner, yes it was good, check
> the shoe thing thats on top of the fan thing on the engine thats seems
> ok too. Now what else should I check I thought, well lets just go over
> everything, this, that, this, that, everything seems ok, but the tail
> belt seems to me like it might be just a tad too tight, so I slacken
> it and then of course its too loose, after a couple of adjustments I
> was happy with the tension.
>
> Right! So the engine is still out, so I decide to remove the backplate
> to see if everything in there looked good, nice and shiny inside, WOW
> that looks nice and smooth.... ahh look there are some bearing, turn
> the motor a few turns, yup they look good!
>
> OK, Backplate back on, time to take of the head, of course this is the
> first time I am taking this engine apart, I undo the head bolts, they
> seemed a little loose, but hey I will tighten those up nicely when I
> put the head back on so no big deal.
>
> I look at the top of the piston in utter dis-belief! I reckon, lord
> that looks ugly, black and not very nice looking at all and if I
> recall my OS .15 max motor's piston still looked shiny and new and
> that had about the same amount of fuel through it. Taking a closer
> look at the piston I notice that there is actually a little bit
> missing from it on the exhaust outlet side. So I have ordered a new
> piston and ring.
>
>
> AND NOW FOR THE QUESTION!
>
> Do you guys have nice shiny pistons at the top or are all of yours
> black and sootie looking like mine?
>
> Simple question I know, but hey worth the story! :)

[Beav]

"James" <system@icon.co.za> wrote in message
news:cc1dcce5.0405010858.5931d16@posting.google.co m...
> Mornin all.
>
> So I was out at the field the other day, was my first time at any
> field with a mate of mine from work. As soon as I started up my
> chopper, he said, !QUOT!Geez that engines running rough!QUOT!. So I
> let him tune it for me. I must admit that it sounded super sweet after
> he had tuned it and almost all of the vibration I had, had disappeared
> entirely. Only problem is that the tail started wagging again.

Probably because now that the engine is running super sweet, it's revving a
tad higher and this will mean a reduction in gyro gain is likely.

If you DON'T turn the gain down on a "high revver", they.... wag their tails
like a happy dog because the TAIL is spniing faster and working more
efficiently.

>
> Geez I hate that wagging tail, its so unnecessary!

And so "removable":-)

>
> So last night, I read up a little here and there including on
> Raptortechnique. I dropped my engine out, checked that the Bell is
> good and true which it was, check the liner, yes it was good, check
> the shoe thing thats on top of the fan thing on the engine thats seems
> ok too. Now what else should I check I thought, well lets just go over
> everything, this, that, this, that, everything seems ok, but the tail
> belt seems to me like it might be just a tad too tight, so I slacken
> it and then of course its too loose, after a couple of adjustments I
> was happy with the tension.
>
> Right! So the engine is still out, so I decide to remove the backplate
> to see if everything in there looked good, nice and shiny inside, WOW
> that looks nice and smooth.... ahh look there are some bearing, turn
> the motor a few turns, yup they look good!
>
> OK, Backplate back on, time to take of the head, of course this is the
> first time I am taking this engine apart, I undo the head bolts, they
> seemed a little loose, but hey I will tighten those up nicely when I
> put the head back on so no big deal.
>
> I look at the top of the piston in utter dis-belief! I reckon, lord
> that looks ugly, black and not very nice looking at all and if I
> recall my OS .15 max motor's piston still looked shiny and new and
> that had about the same amount of fuel through it. Taking a closer
> look at the piston I notice that there is actually a little bit
> missing from it on the exhaust outlet side. So I have ordered a new
> piston and ring.
>
>
> AND NOW FOR THE QUESTION!
>
> Do you guys have nice shiny pistons at the top or are all of yours
> black and sootie looking like mine?

If your engine has been running rich (and it sounds like it has been) you
WILL produce a lot more crap inside the engine. It's carbon build up and
it's normal, but normally it's not a problem because normally, the mixture
is correct. You'rs didn't appear to be normal so you've got an ABnormla
amount of carbon, which in your case IS normal (too rich:-)

Now that you're tail is wagging from higher revs due to a leaner mixture,
thanks to your engine tuning pal, you would eventually have burned off the
excess carbon, but as you've stripped the motor, you saw it before it
diesappeared:-)

Fit the new piston, run the engine in again (which means slightly RICHER
mixture than your new "waggy" mixture) then lean it out slightly so it runs
cleanly and powerfully.


--
Beav


Please note my E-mail address is "beavis dot original at ntlworld dot com"
(with the obvious changes)

Beavisland now lives at
www.beavisoriginal.co.uk

[James]

Morning All,

An update, after I had taken the engine apart and done everything, the
waggin stopped but I was still a little concerned about the piston. I
went to the hobby shop today and purchased a new one. When the guy at
the hobby shop saw my old piston, his mouth dropped open, kinda
because it got so got that the ring fused with the piston itself and
also there was a chunk missing off the top of the piston. When he
found out that I was still flying with the piston yesterday is mouth
fell to the floor...

Anyway, I have my new piston installed, I have the head in some engine
cleaner just to clean it up before I reinstall it so I will do that in
the morning...

I guess I will have to run in the motor again so I will do that after
its all back together, I will probrobly run it in on the bench rather
than installing it in to my Raptor. The engines that I have run in on
the bench seem to run alot smoother than those that have been in
models...

Anyway, I will let you know in a week or so how its going... (Dont
have to be at work for a week)

Happy flying!
James


"Beav" <beavis.original@ntloxoworld.com> wrote in message news:<1097vhrsmi2bea2@news.supernews.com>...
> "James" <system@icon.co.za> wrote in message
> news:cc1dcce5.0405010858.5931d16@posting.google.co m...
> > Mornin all.
> >
> > So I was out at the field the other day, was my first time at any
> > field with a mate of mine from work. As soon as I started up my
> > chopper, he said, !QUOT!Geez that engines running rough!QUOT!. So I
> > let him tune it for me. I must admit that it sounded super sweet after
> > he had tuned it and almost all of the vibration I had, had disappeared
> > entirely. Only problem is that the tail started wagging again.
>
> Probably because now that the engine is running super sweet, it's revving a
> tad higher and this will mean a reduction in gyro gain is likely.
>
> If you DON'T turn the gain down on a "high revver", they.... wag their tails
> like a happy dog because the TAIL is spniing faster and working more
> efficiently.
>
> >
> > Geez I hate that wagging tail, its so unnecessary!
>
> And so "removable":-)
>
> >
> > So last night, I read up a little here and there including on
> > Raptortechnique. I dropped my engine out, checked that the Bell is
> > good and true which it was, check the liner, yes it was good, check
> > the shoe thing thats on top of the fan thing on the engine thats seems
> > ok too. Now what else should I check I thought, well lets just go over
> > everything, this, that, this, that, everything seems ok, but the tail
> > belt seems to me like it might be just a tad too tight, so I slacken
> > it and then of course its too loose, after a couple of adjustments I
> > was happy with the tension.
> >
> > Right! So the engine is still out, so I decide to remove the backplate
> > to see if everything in there looked good, nice and shiny inside, WOW
> > that looks nice and smooth.... ahh look there are some bearing, turn
> > the motor a few turns, yup they look good!
> >
> > OK, Backplate back on, time to take of the head, of course this is the
> > first time I am taking this engine apart, I undo the head bolts, they
> > seemed a little loose, but hey I will tighten those up nicely when I
> > put the head back on so no big deal.
> >
> > I look at the top of the piston in utter dis-belief! I reckon, lord
> > that looks ugly, black and not very nice looking at all and if I
> > recall my OS .15 max motor's piston still looked shiny and new and
> > that had about the same amount of fuel through it. Taking a closer
> > look at the piston I notice that there is actually a little bit
> > missing from it on the exhaust outlet side. So I have ordered a new
> > piston and ring.
> >
> >
> > AND NOW FOR THE QUESTION!
> >
> > Do you guys have nice shiny pistons at the top or are all of yours
> > black and sootie looking like mine?
>
> If your engine has been running rich (and it sounds like it has been) you
> WILL produce a lot more crap inside the engine. It's carbon build up and
> it's normal, but normally it's not a problem because normally, the mixture
> is correct. You'rs didn't appear to be normal so you've got an ABnormla
> amount of carbon, which in your case IS normal (too rich:-)
>
> Now that you're tail is wagging from higher revs due to a leaner mixture,
> thanks to your engine tuning pal, you would eventually have burned off the
> excess carbon, but as you've stripped the motor, you saw it before it
> diesappeared:-)
>
> Fit the new piston, run the engine in again (which means slightly RICHER
> mixture than your new "waggy" mixture) then lean it out slightly so it runs
> cleanly and powerfully.
>
>
> --
> Beav
>
>
> Please note my E-mail address is "beavis dot original at ntlworld dot com"
> (with the obvious changes)
>
> Beavisland now lives at
> www.beavisoriginal.co.uk