Hi guys,

I want to make some smoke with my 120 AX, I know a lot of you will tell me that it's not worth trying to get smoke out of a 2-stroke glow engine, but i'd like to give it a try, I don't want gobs of smoke, just a decent trail without having to run too rich.

The engine will be running on a pump, so muffler pressure is available for other things

I've included a graphic (if you can call it that) with my intended plumbing.

My questions:

1.- Will muffler pressure be enough to get enough flow?
2.- Will the smoke fluid tank explode because of pressure buildup as soon as I close the smoke valve (because of the check valves)? [:-]

Ideas & Suggestions are gladly accepted (as long as it's not a "give it up, you won't get any smoke pal")

I don't think it will work for the simple reason, the pressure coming off the muffler is the same amount of pressure you have to overcome to pump smoke liquid into the same muffler.

Well, the hole at the end of the pre-heat coil will be a lot smaller than the pressure nipple, wouldn't that give me enough pressure difference?

???
I am picturing myself putting 2 straws in a sealed container, one straw with a smaller diameter and blowing into both straws, would fluid come out the smaller one?
I am kind of thinking that the hose size is the same but the fitting is smaller? Perhaps it will act more like a restriction.
Some small amount of force will also be lost going through the 2 check valves and smoke valve.
Interesting.

I understand about how excited you are over this, so I really hate to say it. But you're getting it way overcomplicated. Minnflyer has an excellent How-to on doing smoke that is one of the simplest smoke solutions that I have seen in a long time. You can find it at [link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=455]Got Smoke??[/link] . The other problem you are going to find is that 2-strokes are the worst of the available engines for doing smoke (gassers and 4-strokes produce better smoke), and smaller 2-strokes are really hard to get good smoke out of.

Ken

I agree with you, but a muffler is not a pressurized sealed chamber (as your mouth would be).

If I placed the smoke nipple next to the pressure nipple (side to side, tapped onto the muffler body) then it would be just like you said.

Now picture this.

Lets suppose that I plug the pressure nipple to the tank and I hold the other line in my hand (where the smoke fluid will come out).

As soon as I run the engine, hopefully smoke fluid will come out on the other line (the one I'm holding in my hand).

With the engine running, I take the line I'm holding and insert it inside the muffler exit.

Would the smoke fluid stop flowing? [sm=confused.gif]

I know

MissileMan, Look at the 4th picture

http://www.macspro.com/smkinst.asp [sm=omg_smile.gif]

I was just thinking about that when you mentioned placing it at the end of the exaust, especially if it is angled out, the vortex would actually create negative pressure and will suck fluid in that direction (much like one of those garden hose attachments with a jar for soap, plant food, insecticide ect...)
It may even work by the same principle if you tap an angled (away from engine)line in the flat part of the muffler, near the engine. (that would be where the hottest gasses are so your smoke fluid would have a better chance of heating up)

I think I'll try it first without the in-muffler pre-heat or I'll pre-heat wraping some copper tube around the cylinder head and tap as you said, next to the engine's exhaust port onto the flat part of the header.

If that doesn't work, I'll try in-muffler pre-heat.

If that doesn't work I'll get a 30% Extra and a big gas engine.

If that doesn't work, I'll shoot myself

Why not use a bladder tank, no pump no hastle just off and on and a preheater

This setup would be on/off and a preheater

Would you elaborate please on the "bladder thank" ? [sm=confused.gif]

umm if your using the pump to pump gas/glow into the motor why dont you use that pumo for the smoke and the pressure niple for the tank as most of us do?

Flying Freak:

Because the pump I have is not for smoke oil / petrol based fluids. It's only for glow fuel [&:]