best crank angle of torque
 

I am looking for information regarding the torque supplied to the crank of a rotary engine. My question is this, when looking at just one power stroke, at what degree of crank (after TDC and ignition) is the best lever arm acheived from the rotor pushing on the eccentric cam/crank?

To be more specific, I am not concerned with the pressure building up within the burning displacement, I am specificly looking for the best moment of mechanical leverage resulting from the position of the rotor applying force on the cam/crank and then what is the percent of displacement at that moment.

For example, if there was a constant pressure within the expanding displacement from TDC/ignition all the way to exhaust, then at what degree of the crank would the best torque be acheived and what is the percent of displacement at this moment?

For example, when looking at a piston engine, one with a 4.00" bore, a 3.5" stroke and a 5.95" connecting rod, the best lever arm is acheived at about 74 degrees of crank after TDC which is also at about 43% cylinder displacement.

I believe in a 13B type rotary, the max lever arm may be acheived at about 80 degrees of crank after TDC but the displacement looks to only be at about only 30% of its total displacement.

Can anyone help me with this issue or direct me to technical books regarding this subject?