[AceMan]

I just purchesed The Great Planes Extra 300S .60 size plane at the London swap meet. I always wanted to have smoke system but not sure weather it will work on a 2 cycle engine. I found that the OS91FX has a Inv Pitts OS 91 FX smoke muffler to go with therefor it should work to some degree. Is any one familiar with this set-up, or sugestion on another one to fit this plane and lastly do I have to pre-heat the oil before it enters the muffler. Any info would be super.

[aerodreamer]

ur gonna add a lot of weight to the model by doing this coz u'll have to run a separate batt pack, separate smoke fuel tank and a pump.

but here is one that shud work if u decide to do it anyways

http://www.tmenet.com/products.htm#ssp

[smosher]

TME works really well - just have the weight issue to deal with.

[DO335]

There is no reason that a smoke system will not work on a 2 stroke engine.

While you are at it, don't forget to check out the Sullivan/Slimline smoke pump. It is totally self contained, in one small unit, works with either 4 or 5 cell battery pack, does not need a separate baterry, heavy or otherwise, simply plugs into your receiver and has adjustable output.

You will also find that you get better (more) smoke if you preheat the oil prior to injecting into the exhaust. Slimline mufflers are designed to do this.

BTW, there are also photos, video in action and steps of how a guy added smoke to a Sig Smith Minplane on the net. And that's a lot smaller plane which is more sensitive to added weight than your much larger Extra.

It can be done. Don't believe the experts who say it cant', especially if they've never done it themselves - even more so if it's already been proven to be done. There are too many nay sayers like that around.

[JimMcIntyre]

The key to smoke is pre-heating the oil. Mufflers can be bought with pre-heat chabers or you can wrap copper tube around the muffler/header/head. The trick is to get the correct volume, for this you need some way to restrict flow with a pinch valve (e.g. screw crompressing tubing).

An electric pump & battery are unnecessary weight, connect a check valve to tap crankcase pressure to pressurize the smoke oil tank.

[AceMan]

Thanks for the great info guys, I'll post pictures when I get it done.
Cheers

[AJCoholic]

Aceman,
If I could, I'd like to share some of my experiences.

#1, smaller glow engines are not hard to make smoke, given a decent smoke muffler (preheating the oil with a coil is pretty much necessary).

#2, it is very easy to try and pump WAY too much oil through the system. STart on the low side and work towards more oil a bit at a time

#3, the easiest system is using a 1 way valve, crankcase pressure and a pinch off valve with a micro servo. Much lighter than a pump.

#4, one VERY important thing, you cannot make smoke in a smaller glow engine at anything much under full throttle. Two things, the engine is not running hot enough at reduced throttle settings and more importantly, you can easily kill the engine if you try and pump when at 3/4 or less throttle on many engines. I believe some of the smoke fluid must enter the cylinder (exhaust gasses are regularly exhausted and briefly drawn back in on certain engines in certain exhaust systems). Plainly put, if you turn on the smoke when you are, say, at 1/4 throttle, there is a good chance your engine will die. Please test the system thoroughly on the ground before testing in the air. This is not so much an issue in larger glow engines (like my old Moki 180) or in gasoline engines. But its important in smaller glows.

SMoke is cool but can be a pain in the @ss as well! Good luck!

AJC