PLATE 4175522 - Caterpillar

Probably the most important consideration is that of making sure the engine will cool properly.Two types of cooling systems are used in conjunction with marine engines, keel cooling and heat exchanger cooling systems. Heat Exchanger: Install a 2" or larger sea water intake suction pipe at a sufficient level below the water line so the opening will not be uncovered by a heavy sea. Care should also be taken not to locate this opening too close to the bottom, as sand and dirt will be drawn into the line in shallow water. It is desired to install a duplex type basket strainer with 1/16 inch openings in the suction line between the sea valve and the reverse gear housing to keep foreign accumulations from reaching the gear pump and damaging the teeth. Also, install a drain plug if there is a low point in the pipe between the sea valve and the marine gear housing. Install all drain plug furnished with the tool equipment.Connect a 2" or larger sea water overflow pipe to the outlet side of the heat exchanger. This pipe can discharge directly overboard or a portion of it may be diverted through the exhaust pipe if it is desired to cool same. In this latter instance the location and design of the exhaust pipe must be such that no water can possibly get back into the engine by flooding through the individual cylinder exhaust valves due to excessive rolling and pitching of the vessel when operating on a heavy sea. Keel Cooling: In this system the engine coolant is circulated through coils on the hull. The capacity required for this system must be calculated to suit operating conditions, size of coils and horsepower requirements of the engine. An additional expansion tank is normally used. It is recommended that your Caterpillar dealer be consulted when an installation of this type is planned.