How to figure out what compression should be using MATHS!?!
 

So, I'm wondering if you can figure out what you should be getting on a compression test by using measurements of the motor. Like in a piston motor you can take the bore, stroke, combustion chamber size, blah blah and calculate it to figure out what you should be getting from a compression test.

Is this possible to do with a rotary engine?

probably, but you could also look in the shop manual, and it will tell you...

It doesn't say.

It's an old sachs km-48 from the 70's.

whats the compression ratio and port timing? i can put it in my piston software