hi all let me say one thing more to clear this up in my head
the water flow form the top front cylinder to the tank and then flows to the radiators down thou the radiators the heat is losted to the air and the cooler water is drawn in to the pump number 649 and in to a manifold to each cylinder up through the cylinder to discharge at the top the heated water flow over the top of each cylinder and is discharged it to the tank , the cooler water flows separately to each cylinder and mixs with heated water from the other cylinders at top flowing from cylinder to cylinder and discharged to the tank .. why is it this way each cylinder get it's Owen cooling water and all dump there hot water through the top of the all cylinders .you want cooler water at the pump because of the pressure could cause the water to boil and the pump would cavatate then no water to the motor
here is so thing to thank about the higher the reservoir the less the cavatate that why i think the Germans went to the wing radiator. did they have trouble with the water flow?? i don't know
i will have to look in some boiler book and ask some questions at work to hope fully find out
..... Doug