cagmo

My Feedback: (118)

Building a new jet and was wondering if anyone has put the smoke stick at the fuse/thrust tube aft end as oppose to the common method of just aft of the turbine??

I have room in my new build to do that. Reason is because I want to try to avoid a smoke fire in the pipe (ask me how I know).

For those of you that have done this does it affect the smoke quality? Any tips from those that have tried?

Thanks guys!!

sailing1

My Feedback: (134)

I have done it both ways and prefer the tube at back end. On my Comp Arf Viper I use a Jet Central pump with the shut off solenoid and big two foot long Tams super tube injector. The pipe is 1/8 inch diameter and 24 inches long, running beside the thrust tube so gets some pre heat. The business end is bent 90 degrees so diffuses the smoke oil directly to the center of the exhaust flow. Tremendous smoke and no dripping smoke oil to clean up ever. I don't think I will ever try it any other way.

Jetpilot24

My Feedback: (21)

I run it down between the The double wall of the pipe as well. It works just fine. Be sure to put a one way check valve between the smoke pump and the smoke tube. The pressure from the thrust tube can cause the pump to lose its prime. I also run a header tank on the smoke system. This allows the pump to draw from a full smoke tank all the time.

Here is a video of the system in action. In the video I am using concrete form release oil. It does not get as thick as the commercial brands but it is a little less expensive.

http://www.youtube.com/watch?v=iEKASGZTPsE

Joe Lewis
Kingtech
K-80 and K-140 x 2
Owner

cagmo

My Feedback: (118)

Jetpilot24 - what are you using to 'hold' the injector in-between the inner and outer pipe? high temp silicon? Or do you just let it sit in there without some attachment or glue....

thanks guys! appreciate the help.

schroedm

My Feedback: (1)

This is how I plan to install smoke in my current project as I am fed up with the mess the usual method creates. have never heard of this setup causing a mess.

My question is also how have you secured the injector pipe between the walls of the thrust tube? And have you used stainless steel or brass as your injector pipe?

sailing1

My Feedback: (134)

On my Viper the setup for the injector tube is just like that shown in the picture for Jetpilot24. The tube is a Tamjet injector tube that was sold by DreamWorks. It just runs between the inner and outer walls of he stock Comp Arf pipe and fits snug enough that it does not require anything to keep it in place. The injector tube is stainless and 12 inches long and I had to weld an additional piece of tube on to it to get it long enough. Just purchased the extra 12 inch stainless tube at a local hardware store and had a professional welder fit the two pipes together. The Tams injector has a little stainless deflector that fits on the crimped end of the tube to help further break up the oil flow and sort of direct it back into the flow of the pipe when it is bent at the 90 degree angle as show in Jetpilot24's picture. So after using a tubing bender to get the required 90 degree bend I just shoved the pipe between the walls of the exhaust pipe to the correct depth and made sure the injector was discharging the oil into the center of the exhaust flow. The rest of the setup is pretty much like everyone does it but I would also caution to use a check valve or as in the case of my Jet Central smoke pump, a solenoid valve. Hope this helps.

Jetpilot24

My Feedback: (21)

My injector tube is a piece of 3/16th brass tubing. My local hobby shop sells it in 3 foot lengths. I use a piece of wood with a hole in it to bend the tube. I put a #11 X-acto blade in the end of the tube and squeeze it with pliers. It is just pushed through the double wall of the tail pipe. Nothing holding it in place. The one on my F-15 has enough small bends in it due to the Y pipe on the jet that it is wedged in place. If need be I have used a small piece of Glow fuel tubing over the brass at the end of the pipe to wedge it in place. The heat doesn't seem to affect the silicon tubing.

Joe Lewis
Kingtech
K-80 and K-140 x 2
Owner

ravill

My Feedback: (11)

I'm going to give this a try in my next smoke install.

Thanks guys!

schroedm

My Feedback: (1)

From a material point of view, would stainless or brass absorb heat from the thrust tube more?

Do you think there is any advantage in using one sort over the other? I'm thinking about the pre-heating of the fluid.

Jetpilot24

My Feedback: (21)

I used the brass because of it being readily available at my local hobby shop. I really don't know of any advantage over stainless.

Joe Lewis
Kingtech
K-80 and K-140 x 2
Owner

sailing1

My Feedback: (134)

I doubt that it actually makes much difference which you use with regard to pre heating the oil. It really doesn't stay in there long enough to absorb much heat.

mtnflyer14

[QUOTE=Jetpilot24;11784783]I used the brass because of it being readily available at my local hobby shop. I really don't know of any advantage over stainless."

+1. I used brass on my Viperjet because I couldn't find stainless any longer than 12 inches at the local hardware stores. Have only tested it on the ground so far, so i don't know how long the brass will last as compared to stainless, but I kept the nozzle end out of direct contact with the exhaust, so should be okay.
Regards,
Gus

cagmo

My Feedback: (118)

Thanks guys. All great ideas!

Is there a need to have the end go direct in the exhaust? Seems to me that if not, the oil can get 'blown' past and not injected into the highest part of the heat concentration. Thoughts?

sailing1

My Feedback: (134)

Pump it into the middle -- you won't be sorry!