Roger, thanks for your detailed answers. It should not ne too difficult when I cut some cardboard to reduce the efficiency of the aluminium radiator, which consequently to your thoughts should help to lower the water temperature of the engine.
I have understood the consequences and effects but I haven't really fully understood how it works and how the connection between the warm bypass water and the cooler radiator water come together.
I assume that both water hoses meet before the thermostat. But how is the mix determined, and why does too little cold water seem to come into the circuit towards the engine behind the stat when the new radiator cools so well, better than the old smaller plastic radiator? But the engine runs hotter...
