we all know that a cd only holds 700 mb
I do not know where you have got that illusion from, but there are CDs with 800MB (90 min) as well. Just go to your local computer store and ask for them - if they do not have them, they do not deserve the label "computer store".
BUT if you use illegal downloads (which they probably are), then you should refrain from proceeding to burn the games to CDs! It is illegal and it damages the software industry. However, that does not bother most people who believe that deceiving insurance companies is all right in some way and that "small amounts" do not affect the system - well, they DO!
Think about it the next time your insurance policies become more expensive or CD/DVD prices are higher.