Compression is used to ensure the fuel is burned as complete and as fast as possible, however anything more than needed to reach that goal is wasting energy to compress the mixture. You might be surprised to find a Pro Stock engine runs at or less than 15 to 1... You may want to talk to Chad Speier, he did the heads for the Parks ND cars and might give you some advice on your project. He has a tech forum here.
http://1320techtalk.com/