I had a pitts muffler made for my jba 15 and wondering about the smoke tap. I was thinking about brazzing a piece of brass tube on the end of the pressure fitting and flating the rod until i i got spray effect or am i fine with just screwing in the tap and decreasing the flow of smoke oil?</p>

You don't need a spray. But it would help to run the oil tube right to the engine's exhaust so that you introduce the oil to the hottest part.

For more info, read this:

[link=http://www.rcuniverse.com/magazine/article_display.cfm?article_id=455]Got Smoke?[/link]