smoke systems
 

just put the funtana 90 together with a 91 os fourstroke. thinkin of a smoke system, not sure if this engine will produce good smoke. I would like good smoke or is this a waste of time??? looking for the best results!! thanks

smoke
 

Quality smoke goes like this:

LOW - 2 stroke glow - 4 stroke glow - 2 stroke gas - HIGH

It is the exhaust temperature that determines the quality of the smoke. Preheating helps with smoke quality (coiling some soft brass tubing around the muffler prior to injection).

A 90 4 stroke will smoke just fine. But - no matter what system you use - SMOKE IS REALLY MESSY!

Do a "smoke" search on RCC - this has been discussed before.

Peter

re: smoke systems
 

Smoke rocks! Yes its messy and expensive, but worth it I think. It's not going to make a glow model that much more dirty. You really notice the mess on a gas plane though, since gas exhaust is pretty clean otherwise.

I run a TME electric pump on a ZDZ 40 gas engine. It works pretty good, though the weight penalty in a smaller plane would be bad.

I haven't installed in a four stroke before, but have a friend suggested this method should the need arise:
http://www.greathobbies.com/document/tech_smoke_1.html
This method uses only engine pressure so you save the weight of batteries and electric pumps.

SuperDri is great smoke oil, but can be costly when you're running 2oz a minute into the muffler. I use it when someone's looking but usually I run a 50/50 diesel/kerosene mix. It works all right on its own, but doesn't linger like SuperDri. I have been adding some tranny fluid to it and that seems to increase the hang time. I picked up some Heritage Lamp Oil recently to replace the tranny fluid. This lamp oil has warnings all over it about smoke damage so that's a good thing! For the cost of it, though, you may as well buy the SuperDri unless you mix the lamp oil with something cheaper like the 50/50 mix above. I haven't tried the lamp oil blend yet.

Good luck...

How heavy are smoke systems? I heard that they are pretty heavy, especially with smaller planes.

most of the weight is in the volume of oil required.
Think of adding another fuel tank full and you get the idea.

The battery powered pumps are heavier (obviously), the weight is typically in the batteries. But you get what you pay for ... more volume = denser smoke.

Great information and link, YellowBird. I am considering smoke for one of my planes and I too appreciate your input! Thanks very much for sharing this with us!

smoke systems
 

thanks for the info, It looks like great hobbies smoke system will work best for my application

just reading this makes me want to try out a smoke system. can't wait to put together another project and try it out... :D

I had used that dubro method in my Hog Bipe w/ Saito .91. Results were sporadic at best. The check valve, had 2 replacements as it would build pressure, blow out about 5 seconds of smoke then stop. I would close the release for 10 seconds, re-pressurize, then open again. My advise would be to use a better quality check valve as a start.

Also the LHS sells two types of tubing for smoke oil; Tygon and the yellow transparent stuff. For the connections to the muffler and header use the Tygon stuff (black) as the yellow stuff melts (remember gas doesn't use muffler pressure so it isn't heat resistant)

The hardest part was wrapping brass tubing around the header without crushing it. I used the ice method finally (fill with water, put in freezer, wrap around header, let ice melt, secure with JBweld)

It's a great system to play with and try it out though. I ended up getting a smoke pump (Sullivan Skywriter) for my next project.

Bob

thanks for the tips, greatly appreciated.