Please tell me about smoke systems.
 

I have a 4* 120 that I may(?), want to add smoke later this spring/summer. It will get it's maiden flight in a couple weeks....sooooooo, I have plenty of time to learn about smoke. I have only heard a few things and they have been negetive. Covering problems, special mufflers, heaters, blah blah. Is there a "simple" system out there. I will forget it if I need a special muffler. I have a Saito flex pipe running from my Saito 150 and it will be staying. Can it be used?
Thanks in advance....lownslo..

Bob

Hmmmm..... nobody smokin' ??
 

Maybe no one is smokin' anymore.... since I didn't get a reply yet. ;) Maybe the "no special muffler thing" stopped any replies in their tracks. Simply stated: I am not needing a top notch smoke system. I am a sport flyer, not worried about competition type flying. I just wanted to have a little fun with some smoke once in a while. In other words ....is there a light, simple system, that I can still use my Saito flex pipe exhaust for smoke? (accepting the fact that the amount of smoke would be reduced).
thanks.....lownslo

Bob

Please tell me about smoke systems.
 

Bob,

There are several simple systems on the market: TME Simple Smoke Pump, and SlimLine come to mind. You can also get a windshield washer replacement pump from WalMart, or an Auto Parts store for about 8 bucks.

As far as smoke oil goes, I like UltraSmoke From Air Capital Hobbies. It's not petroleum based, so it doesn't attack covering or foam, and it doesn't stink.

The biggest thing to remember about smoke systems is that they're finicky. They need to be set up and adjusted just right. Your standard muffler will do fine, but you'll have to modify it just a little. You need to add another pressure fitting to it so you have a place to pump in the oil. Placement is fairly critical. It needs to be in a low-pressure area of the exhaust. The narrow part of the muffler where it just leaves the head is ther best spot (the big barrel of the muffler where the regular pressure fitting is located is a high pressure area).

Once set up, you need something to regulate the flow. Too much oil will kill the smoke because it cools the muffler.

Please tell me about smoke systems.
 

Thanks for the info minnFlyer. I did happen to run across that Ultrasmoke info the other day....and that would definately be my choice.
It is good news about the flex exhaust I have. One problem there.... the flex pipe has a smooth pipe "header" that leaves the engine. The factory pressure fitting is welded into a "belt" of sorts, where the corrogated, bendable, pipe starts. (the present pressure fitting is about 2 inches from the head). I am thinking I should use THAT fitting for the smoke and the pressure to the tank welded in "BEFORE" the smoke fitting. My thinking here it to not put smoke fluid in BEFORE the pressure fitting...so as to not contaminate the fuel if some of it should travel the pressure line to to tank. Because I don't have the years of knowledge some guys have.... I don't know if I will mess up the amount of pressure by getting it too close to the head... and how far before the smoke fitting would be safe etc.
I don't have an on-off switch available, (used the LG for something else), on my radio..... but read this morning I could somehow make the smoke come on at 1/2 throttle or more. (unfortnately.... it is also my first computer radio) :rolleyes: So if you wan't to "bail" now, I will understand!!:D ...... lownslo....

Bob

Please tell me about smoke systems.
 

By the nature of the beast, you pretty much HAVE to put the oil in before the pressure tap, here's why:

The narrow part of the muffler causes the exhaust to flow fast, which creates a low pressure area. In the barrel (or expansion chamber) of the muffler, the flow is slower, but the pressure is greater. THIS is where a muffler is SUPPOSED to be tapped for pressure.

So if you have a nipple on the flex hose already, that's a perfect place to attach the oil line. Then, just tap the muffler body for fuel pressure.

I really don't think you will have a problem with fuel contamination. The minuscule amount of oil that gets in will only add to the oil that's already in the fuel.

Please tell me about smoke systems.
 

Me thinks you best have a large smoke oil tank. ;)

From what I've seen, smoke (oil) doesn't last all that long. I would think you'd be unhappy with the duration if it's going to run whenever you're at full throttle. (Unless you've got a LOT of extra power.)
Dennis-

Please tell me about smoke systems.
 

If you go with the windshield washer pump, you can set it up so that at the very end of travel, the servo arm will hit a (Radio Shack) microswitch to power the pump.

Please tell me about smoke systems.
 

Thanks fellas, I can see I have to think some more on this. Hey Dennis, I do have the power there but I do see what you are saying!! It may be best to do a micro switch.....thanks again..lownslo..

Bob