If you want an 8.5x11" image, you have to print on oversized paper (possibley 11x17) and trim it down to the size you want. Your printer won't print all the way to the edge and that is the reason that you have the white space around the edges. The only other thing you can do is trim off the white and scan the image and inlarge it to the size you want.
Hope this helps.
