ORIGINAL: RBean
The plane will almost certainly come out tail heavy. So a light weight engine is not needed or desirable. A heavier engine will not hurt. Also in your build keep all weight as far forward as possible including building mounts for you batteries and ignition module in the cowl as far forward as possible and keep everything in the tail as light as possible. You will probably still need to add nose weight but maybe not too much. Thats how it was on my 72'' wingspan CMP Zero. However, it should be a great flying airplane.
i couldnt agree more than that! i also have cmpro zero 72ยจ and its one of my best planes! its about 9,5 kgr!! now after some repairing , i have dle 30cc and it flies like on rails, i had to make a pair of split flaps though for slow landing approach. i had to put over 1 kgr of dead weight in front for balancing at about 1/4 of the wing root. my estimation about esm zero is that if you would like to balance it at the same point (1/4 of wing root chord at the point where wing meets fuselage) you will probably need over 2 kgr of dead weight in front with a 50-55-60cc gas engine(except zenoah), but i am really sure that plane will fly lovely. .....why not a ......dle 80cc for a more scale like prop;