The flame on my zippo is too high, 4 inches, how do i turn it down?

We're talking the clic, with a wick which uses lighter fluid, right? If so, you have the wick too high. You can either trim the wick down a bit OR open the body, and pull out the wadding to get at the wick and pull it back down a little and then repack the wadding. Remember how the wadding came out so you can reverse the procedure to repack it correctly, as the wick makes S curves through the wadding. The noise you are hearing is simply the air flow through the holes in the chimney because of the large flame. Any fire will "roar" with sufficient air flow, such as with a chimney.