If you want to make a clean install of the new OS X Mavericks or even the older versions of Mac OS X, than I strongly suggest you to create a bootable OS X key or a drive.
You deleted everything from your USB key or a drive, so there should be enough free space to copy the new files, but you still get the not enough free space message in Mac OS X? This is what you need to do.
We have already learned how to create a bootable OS X Mavericks USB drive using a third party app, this time I will show you how to create one directly in Mac OS X.
Without too much fuss, Apple released a new version of its OS X operating systems for Mac computers. The great thing about it is, that it's completely free for the existing Mac OS X users.