(under subclass 41.21) Cooling systems in which vapor and water flow from the block or cylinder jacket through the same or adjacent outlets and the water is separated from the vapor and returned to the block or cylinder without passing through the condenser for the vapor.
SEE OR SEARCH THIS CLASS, SUBCLASS:
41.24, for similar systems in which the vapor and water flow from the top of the block or jacket to the bottom of the radiator.