Water/Glycerol: This coolant is required in order to collect heat from the Jacket Pump (JP). Water is considered to be the best coolant and heat collector at temperatures below 100°C, but it becomes less effective at higher temperatures, if it is not under pressure. Glycerol (Glycerine) has about half the heat conductivity of water, but it's boiling point is three and a half times higher than that of water. It has a specific heat capacity above 100°C that is 2.43 KJ/KgK. It will cool at temperatures above 100°C, without turning to vapor, when it exits the container. There are not many examples of water cooling, if the temperature of the water is to be very much above 120°C. The simple solution is Glycerol (Glycerine) coolant for temperatures above 100°C or a mixture of both Glycerol and Water.
The maximum allowed temperature of the content that is in the Water/Glycerol container together with it's size and the amount of propellant that it must cool per unit time will define the cycle time of the system.
That means how much time the system spends collecting heat in the Water/Glycerol container and how much time it spends using that heat to drive the Turbine.
You will have to find the correct amount yourself, because there is no public documentation about how much heat is dissipated by the radiator of an internal combustion vehicle and how much is dissipated on other surfaces over which air will flow.
The goal in the SHE is to release as little heat to the outside world as possible and as slowly as possible, so that there is time to reuse some of it on a constant basis.
spent heat back into a solar heat engine