VF84sluggo

My Feedback: (55)

I'm setting up a smoke system in a JL Viper. My question is about smoke tube location.

I've heard that putting the smoke tube aft of the engine exhaust nozzle is bad for the tail pipe, that the cool smoke oil injected here puts thermal stress on the pipe. I've seen where guys run the smoke tube between the tailpipe walls and bend it into the hot exhaust at the pipe exit. There is supposedly an added benefit of preheating the smoke oil with this setup. I can see another benefit here in that there would be no oil residue in the tail pipe.

The problem is the JL smoke tube isn't long enough to run all the way to the pipe exit. I see where some just place this tube inside the tailpipe, and live with the oil being sprayed into the pipe at about the midpoint of the pipes total length.

So, for those who use smoke with a tailpipe jet, how do you do it?

Thanks,

Sluggo

Edgar Perez

My Feedback: (13)

There was a thread talking about using long stainlees steel tubes that you could buy at McMaster.

VF84sluggo

My Feedback: (55)

Ok thanks. I'll look for it.

Jetpilot24

My Feedback: (21)

I use 3/16th Brass tubing from my local hobby shop. They have it in 3 foot lengths. It works just fine. just remember to put a one way check valve between the pump and the smoke tube other wise the air velocity will push the prime out of your pump and back into the smoke tank.


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

VF84sluggo

My Feedback: (55)

I was wondering if brass would work, or if the tube had to be stainless.

Never heard about needing a check valve. I didn't use one with my Tam setup in my Baby Boomer. Is the check valve needed because of the smoke tube at the end of the tailpipe setup?

Also, I did email Tam, and he says there is no need to put the smoke tube exit at the end of the tailpipe, that using a standard smoke tube with the end of it placed behind the end of the engine exhaust nozzle is the way to go. He told me in his email that he has not seen this to cause any thermal stress or tailpipe damage, or any other problems from smoke oil being injected into the exhaust stream right behind the engine and in front of the bellmouth.

I do wonder if the smoke would leave a messy residue in the pipe, though. That reason alone would make me favor injecting the smoke oil at the end of the tailpipe, not in front of it. Tam did say that injecting the oil at the end of the pipe would result in less smoke and oil just being blown away unburned.

Any thoughts on all this?

Thanks