Glowing ring

Hi, I'm new with unity, I started with it about 5 days ago. I watched some video's on youtube (tornadotwins) but ofcourse these "quickstart" videos dont cover even half of unity's features.
So, I started creating some space sim game since I learn the best whilst doing. Now, I want to create some glowing ring around my spaceship's engine. I want to make it glow more or less intense depending on how much power you send to the engines so editing the texture of the model into a glow ring on the engines won't work I guess. After some googling I saw people talking about the rendering => halo option but this doesn't really seem to do what I want either. Any hints on how to do this?

Here's an image with what I mean: http://i51.tinypic.com/hrxzj4.png