Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Hi,
I am building a BAe "Red Arrows" Hawk and want a smoke system like the real thing.
But Because the smoke unit would be up front with the silencer and bits, the smoke would have to come out of the wrong place, and this would not look right.
I was thinking that I'd have a the .91 up fornt with box silencer then drill a hole in the side of the fuz and feed flexi exhaust from the box silencer through into the fuz, where it would connect to the smoke unit. Then from the smoke unit a bit more flexi exhaust then possibly some sort of ducting down the tailpipe to then let all the smoke come out of the tailpipe!
What do you think?
If my plan won't work, can you clearly suggest another one!

Thanks for your help
Dave

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

It won't work... :D

The smoke will condense again before it passes out the back... you'll have oil dribbeling out the back of your plane instead of smoke... sorry to disappoint you...

The key to smoke is heat, and with a pipe all the way to the back all the heat will be gone.

If you can live with the sound of a jet plane powered by a piston engine, why can't you live with the smoke comin' out the front instead of the back? :p

If you need smoke, just install a standard smoke system... and don't try to get cute... it will save you a lot of headaches...

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

cheers, thought there might be problems with it.
Thanks anyway!
So the shorter distance the smoke has to go, the stronger it'll be!



Cheers
Dave

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Would there also be a pressure problem for the engine?


Dave

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Not if the exhaust duct in the fuz is large enough.

Different outlet
 

Directly below the smoke unit that's inside the fuz?

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Nice plane!!! May I ask where you got it??? Very nice indeed!

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Aerotek UK, but they're not readily available. Please look here for more info on a US model http://www.rcuniverse.com/showthread...k&pagenumber=3


Good luck
Davee

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Dave,

Your situation is curious to say the least. As Rudeboy said, the key to good smoke is heat. You have that near the engine. The problem with 2 strokes is that because there is an exhaust stroke for every revolution, the oil rarely stays in the muffler (silencer) long enough to get up to temp. However, if you are running an extra long tailpipe, that should solve that problem.

I'm not saying that it will work, but if I were going to try it, here's what I would do:

Inject the oil at the muffler's intake, as close to the engine exhaust as possible. You may even want to wrap the head once or twice with copper tubing as a perheater for the oil. Make sure that you have a flow control on the oil, too much, or too little will not smoke. I really see no reason why it shouldn't work, but then, Murphy's law can come in to play at any time. :)

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

A buddy of mine flies a 100" wingspan Giles 202... it has a 4.5 CID gas engine on a tuned pipe for power... he can't use smoke in his freestyle program because of the long tuned pipe... the pipe barely gets hot at the rear... on a regular muffler he had huge smoke...

Dave, just rig something up with a long tailpipe for ground testing, and see what you get... if it don't work on the ground it won't work in the air either...
Don't make huge mods on that plane without knowing for sure it's gonna work...

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Thanks MinnFlyer and Rudeboy for you help. I'll try it today!

Cheers, i'll keep you posted.

Dave

Alternative
 

The bloke who I was buying it off, didn't go flying!

The Attached Photo is of the smoke systems bits (excuse the term) and how they should be connected up.
next is the same system but shuffled around so that the smoke will come out the bottom of the fuz, under the cockpit, and before the wing.

.
 

Plan of venting smoke, out of bottom of fuz

how it shoud look
 

.

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

what do you think?
It's going to be a challenge

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Don't use a "pressure control valve"... pump that tank up hard (all you can get)... and control the injected amount of smoke fluid with a needle valve close to the injection point...

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

I agree with rudboy, you want to control the flow, not the pressure.

Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Ok thanks!

RE: Smoke out of Red Arrow tailpipe, but its a prop jet!
 

Dave, have you thought of saving all that weight and using a smoke bomb? There is an ad for them on the main page, they even have multiple colors. Ya cant do that with oil! I know it sounds cheesy but it may look cool. You can also get smoke generators (the pc term) from McMaster Carr item # 4093K12 they produce 40,000 cubic feet of smoke in 2-3 minutes. I have some ordered and am going to use rocket igniters to light them. This method should allow you to make smoke in the back like you wanted.[sm=pirate.gif]


Not yet a revver brother, gotta get some pics.