OS FSa-56 and smoke
Steve
Pitts) and one of the reasons for the choice is I wanted to use smoke
on it. I've tried smoke on 2 strokes and it didn't work all that well
and I've been told 4 strokes are the way to go for smoke. I can't
seem to find a smoke muffler for it though, and I'm wondering if I'm
missing something. Is the engine too small? Can I just tap the
factory muffler?
Thanks,
Steve
Martin X. Moleski, SJ
<f39b5bdc-bb2c-426b...@v30g2000yqm.googlegroups.com>:
No harm in trying. If it doesn't work, just seal the
hole with a short bolt.
I tried to do smoke once. I still fantasize about trying
it again. I had a hand-me-down pump that was unreliable.
It was no fun and the experiment did not last long. But
I love to see smoke!
Marty
--
Big-8 newsgroups: humanities.*, misc.*, news.*, rec.*, sci.*, soc.*, talk.*
See <http://www.big-8.org> for info on how to add or remove newsgroups.
Six_O'Clock_High
"Steve" <sca...@aol.com> wrote in message
news:f39b5bdc-bb2c-426b...@v30g2000yqm.googlegroups.com...
There are two problems with smoke in model airplanes.
The first is the delivery of the fluid to the exhaust. Various pumps fix
that leaving the second challenge to be worked around. I don't think there
is enough available vacuum to run the smoke pump and supply the 4 stroke
with fuel, but I have not tried that yet.
Most model aircraft SMOKE mufflers (see, they recognized the 2nd problem and
tried a solution - that sort of works) have a coiled tube inside to preheat
the smoke since our engines operate at significantly lower temperatures than
rider scale engines and have shorter exhaust systems.
I have seen a modeler put a single coil of 1/8 brass tubing around the head
of a 2 stroke engine to preheat the fluid, but *I* wouldn't for fear of
cooking the top end of the engine. However, you can put a wire inside the
tubing and wrap a couple of turns around the exhaust header of most 4 stroke
engines before the fluid is injected into the muffler. Once the wraps are
made, pull the wire out since it was just there to keep the walls of the
tubing from collapsing. I would buy some JB Weld suitable for heat and use
it to try to control, stop, or prevent the metal to metal vibration you may
get to protect the integrity of the radio system. Pump the fluid through
the tube and then into the exhaust muffler and you should get smoke.
Smaller engines may need more wraps to get the oil hot enough for the short
time it is in the exhaust chamber.
Good luck.
Steve
> of a 2 stroke engine to preheat the fluid, but *I* wouldn't for fear of
> cooking the top end of the engine. �However, you can put a wire inside the
> tubing and wrap a couple of turns around the exhaust header of most 4 stroke
> engines before the fluid is injected into the muffler. �Once the wraps are
> made, pull the wire out since it was just there to keep the walls of the
> tubing from collapsing. �I would buy some JB Weld suitable for heat and use
> it to try to control, stop, or prevent the metal to metal vibration you may
> get to protect the integrity of the radio system. �Pump the fluid through
> the tube and then into the exhaust muffler and you should get smoke.
> Smaller engines may need more wraps to get the oil hot enough for the short
> time it is in the exhaust chamber.
I did this on a 2 stroke and it barely worked. I wrapped a 12" length
of 1/8" copper tubing around a dowel aa few times and stuck the whole
thing inside the muffler. I drilled out the muffle and had one end
sticking out (with the requisite JB Weld....) and had the other end
positioned right in front of the exhaust. It wasn't hard to do, and
might've worked better with a bigger engine (I was using a .46) but I
wasn't impressed. I was hoping to do better with a 4 stroke, but
maybe I just need a much bigger engine (and a bigger plane!!)
Thanks,
Steve
MJKolodziej
"M-M" <nospa...@ny.more> wrote in message
news:nospam.m-m-8DC4A...@cpe-76-190-186-198.neo.res.rr.com...
> In article
> <f39b5bdc-bb2c-426b...@v30g2000yqm.googlegroups.com>,
>
> You do not need a smoke muffler, or a pump, or a coil.
>
> You use the muffler pressure and a one-way valve to pressurize the smoke
> tank. One servo to actuate a switch to allow the oil into the muffler.
>
> Details on my website:
>
> http://www.mhmyers.com/rc.tn.html
>
> Here is a photo of my Smith Miniplane with a FS .52 and smoke:
>
> http://www.netaxs.com/~mhmyers/cdjpgs/bipesmoke.jpg
>
> --
> m-m
> http://www.mhmyers.com
Smoke pretzel Cool!
mk
ecregger
"MJKolodziej" <mjmwcsREMOV...@htcomp.net> wrote in message
news:hfetlr$ff8$1...@news.eternal-september.org...
Very interesting stills and videos. Thanks for posting the info. Very
entertaining and well done.
Ed Cregger
IFLYJ3
In the order of ranking of least to the best for smoke is; 2 stroke
glow engine, 4 stroke glow engine, Gasoline engine.
I have not done smoke, but I have measured exhaust gas temperatures.
On a 2 stroke the most I found was 450 degrees F at the exit of the
engine. I could move the thermal couple inside the muffler a 1/4 inch
and get a 50+ degree change. By the time the exhaust exits the muffler
is is very cool.
A 4 stroke with range over 700 degrees F at the muffler. A gasoline
engine can be up to 1600 degrees. You can see which one will produce
the best smoke.
The reason for the coolnest of the 2 stroke glow is some of the
incoming fuel goes out the exhaust for cooling reasons whereas it
doesn't in the 4 stroke.
I have seen excellent smoke from a gasoline engine. Decent smoke from
a Saito 100 with a smoke muffler (coil inside) and no smoke from a 2
stroke.
If you get any smoke from a 2 stroke glow, it will be pure luck.
My $.02 FWIW
M-M
<a2b658d9-0b72-46fb...@g31g2000vbr.googlegroups.com>,
IFLYJ3 <wb4...@aol.com> wrote:
> I have measured exhaust gas temperatures.
> On a 2 stroke the most I found was 450 degrees F at the exit of the
> engine. I could move the thermal couple inside the muffler a 1/4 inch
> and get a 50+ degree change. By the time the exhaust exits the muffler
> is is very cool.
> A 4 stroke with range over 700 degrees F at the muffler. A gasoline
> engine can be up to 1600 degrees. You can see which one will produce
> the best smoke.
> The reason for the coolnest of the 2 stroke glow is some of the
> incoming fuel goes out the exhaust for cooling reasons whereas it
> doesn't in the 4 stroke.
>
> I have seen excellent smoke from a gasoline engine. Decent smoke from
> a Saito 100 with a smoke muffler (coil inside) and no smoke from a 2
> stroke.
> If you get any smoke from a 2 stroke glow, it will be pure luck.
Great info, thanks.
Here is a photo of what I think is very decent smoke from an OS .91
Surpass without a smoke muffler or pump:
http://www.mhmyers.com/d80/DSC_21002w.jpg
Another shot, in flight detail
http://www.mhmyers.com/d80/DSC_29020w.jpg
--
m-m
http://www.mhmyers.com
Dave Plumpe
- What do you use for smoke fluid?
- Is the oil injected thru any kind of spray nozzle, or just dribbled into
the muffler?
- I'm surprised there's enough pressure differential between the "Muffler
Pressure to Smoke Tank" and "Smoke Oil to Muffler" lines to pump the fluid.
-Dave
--
http://plumpe.home.mindspring.com
email: last...@mindspring.com
ANTI-SPAM: To email, replace "lastname" with "plumpe"
"M-M" <nospa...@ny.more> wrote in message
news:nospam.m-m-BF8C6...@cpe-76-190-186-198.neo.res.rr.com...
Steve
> > Pressure to Smoke Tank" and "Smoke Oil to Muffler" lines to pump the fluid.
You can use a check valve to prevent the pressure from "backing" out
of the tank.
The smoke system I have has a tiny electric pump that hooks into a
spare receiver channel. You can put it on a channel with a switch and
turn it on and off.
The real fancy guys put it on a switch and mix it to the throttle
channel so that, even if you turn the switch on, it'll only start the
pump above half throttle.
Steve