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Smoke System Question

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Smoke System Question

Old 05-27-2013, 12:46 AM
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Default Smoke System Question

I have seen a couple of posts fairly recently (but I can't find them now [&o]) suggesting that when using a smoke system with a 'standard' engine installation using a thrust pipe, the smoke fluid should be injected at the end of the pipe and not behind the turbine.

Does using this method still produce good smoke? Is the exhaust still hot enough or does the smoke fluid need some sort of pre-heating?

Has anyone had any problems injecting the fluid into the turbine exhaust directly (i.e. before the pipe?).

I've used smoke before on an 'open' system, so know how to set it up, but not when using a thrust pipe.
Old 05-27-2013, 04:23 AM
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Default RE: Smoke System Question

IMHO any kind of "preheating" system is not a good idea in rc jets.
Spray the smoke right after your engine (at the bell mouth) this will give you the best result.
At the rear end of the pipe exit the gasses have been cooled down from the cool air that comes from the bellmouth ventury effect (designed to cool the pipe)
Use a good quality smoke fuel like the Power-Box juice http://powerbox-systems.com/e/powerb...pump/start.php
Poor quality smoke fuel can ignite and the flame will damage your pipe....guess what will happen if the pipe will collapse when you are airborne ...

Carry as much smoke as you can...i cant get enough https://www.youtube.com/watch?v=v38FGYLEbtg

sorry for the poor english
Old 05-27-2013, 06:58 AM
Dave Wilshere
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Default RE: Smoke System Question


Poor smoke if you take it to the back, you would have to vaporise it really well to get anything decent.
Only problem with in tube and injecting it behind the turbine is the people with too much flow and the excess oil drains into the fuselage and makes a mess. You can also get a "reverse" effect on some un bye-passed installations (turbine air suck greater than exit velocity) and it will suck oil back around the outside of the tube...makes a mess

Old 05-27-2013, 07:22 AM
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Default RE: Smoke System Question

If using a pipe try to keep the usage of smoke pass half throttle to prevent an incease of temp and to get the best smoke trail possible.

Also inspect the pipe on a regular basis.

That's my recomendation.
Old 05-27-2013, 07:49 AM
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Default RE: Smoke System Question

I use both systems one with Tams system and nozzles heated from engine and sprayed behind the exhaust and the other using powerbox pump plus home made brass tube nozzles heated passed through the double wall of the thrust pipe and sprayed at rear of pipe. sorry cannot post pictures..usual 500 error appears.
Old 05-27-2013, 08:03 AM
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Default RE: Smoke System Question

Try clearing your search and cookies to see if that helps.
Old 05-27-2013, 11:39 AM
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Default RE: Smoke System Question

DO NOT spray the smoke oil in right behind the turbine. I have seen some installs like that, A pool of smoke oil form in the pipe then a flame on start up. I inject mine right at the back of the tail pipe. I use a piece of 3/16th Brass tube and a one way check valve between the injection tube and the pump. This stops any blow by the pump thus causing it to lose its prime. Here are some pics of my install. The Smoke system is contained completely in the center drop tank. one hook up for the smoke pump and another hook up for the smoke oil line. Also a video of it working. Injecting the oil at the back of the tail pipe.

With this set up you also get the gap between the jet and the smoke trail just like a scale jet.

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Old 05-27-2013, 06:06 PM
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Default RE: Smoke System Question

It is quite acceptable to spray smoke fluid 1 to 2" behind the turbine exhaust....but make sure you have a decent nozzle (ie Tams) and have a shut off valve on the smoke line so smoke fluid can not dribble out until the engine is started and running. Any drips (if any) after that point will get blown out the pipe, or vaporized.

I find the smoke fluid keeps the pipes clean and shiny for years..

The only "Don't do's" that I would suggest is:
Don't turn the smoke on at idle on the ground - you just might get a flamer..
Don't land with smoke on - you can't see the jet when it rolls past you....(no need to ask how I figured that one out!)

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