[Gold Digger]

I remember some older IH truck engines had what was called a "recirculating tube" that slipped inside the engine block. They were thin metal with a lot of holes in them and was made in a tapered configuration that slipped in easy and rust took over and was hell to get out. There was other engines made to use this type of water circulation. When they rusted partially out they over heated and not many people could figure out what was wrong.