Quote:
Am I right in thinking the feed from the header tank needs to be after the radiator for the water pump to be working properly, at least on the slant engines? I’m sure I read that.
Yes is the simple answer.
To be more precise, the feed from the header tank needs to be plumbed into the cooling system before the water pump,
the best place being the bottom hose. This ensures there is always coolant ready to be circulated by the water pump.
(As this relies on gravity, the best combo is having the header tank as high up as possible allied to a pump situated as low down as practical.)
This is true for all engines, not just slant fours.
Ian