Re: stroke length, does it matter?
Torque is basically a result of the pressure on the piston caused by the ignition of the mixture being converted to rotational force.
The faster the rotation, the higher the power at the crank, until the valves cant keep up.
The perfect crank (for power) has 90 degree (sine) offset, but this is all a bit schoolboy basic.....
The answer is, there is no answer, there are too many variables for any single feature to be of significant importance.
The 'perfect' engine (in theory) is only any use at one crank speed, so all car engines have fundamental inefficeicies and flaws to allow them to operate over a fantastic range of crank speeds and deliver meaningful torque.