thermo siphon cooling V water pump assisted

[davidO]

Hi, I am presently engaged in restoring a 1914 12 HP dickey seat roadster. I have a number of engines available to me and as none appear to be the original matching my chassis I have to make a decision regarding which to use. I have cylinder blocks some of which have the square water inlet suiting a thermo siphon cooling system and other blocks with the round inlet suiting a water pump, (or water accelerator as described in the manufacturers literature) Can anyone enlighten me as to whether or not the earlier 12HPs had a cooling problem which encouraged the fitting of a water pump, or was it just a matter of using a more modern system? I would prefer to use a thermo siphon system as I seem to have constant battles with keeping the water pumps water tight on my other vehicles, but not if there is a cooling problem without the water pump. I have the appropriate radiators to suit both thermo siphon and water pump assisted systems. Can anyone offer advice?