TII compression ratio
 

Just a real simple question cos I can't find all my info papers cos im in the mddle of movin house and its lost in boxes sumwhere.
Anyway, Im lookin at another Rx-7 tonight, a 1989 13bt, I mainly only want it for parts, it supposedly has blown water seals, still runs but overheats, its NZ$1000, How can I check to see how damaged the water seals are or if is Actullay is the seals that have gone. Is takin the radiator filler cap off an lookin for bubbles the best way? I also need to know the compression ratio it should have to see how the rest of the motor is because I might like to rebuild it when im feeling rich. Anything below 6 on each seal is too low, isnt it? thanks.