13101-ZW2-F00 Honda PISTON (Honda Code 7529258).

Jacket Water System
Illustration 1 g06505503
(1) Coolant supply to turbocharger
(2) Coolant from turbocharger to radiator
(3) Coolant from cylinder head to temperature regulator housing
(5) Outlet for coolant to radiator
(4) Coolant temperature regulator housing
(6) Water-cooled exhaust pipe
(7) Coolant from water-cooled exhaust pipe to cylinder head inlet
(8) Coolant from cylinder head to temperature regulator housing
(9) Bypass tube
(10) Tube to the coolant tank
(11) Coolant supply line to the water-cooled exhaust pipe
(12) Oil cooler outlet that supplies the right side of the cylinder block
(13) Oil cooler
(14) Jacket water pump
(15) Coolant return from the radiator to jacket water pump inletThe jacket water pump (14) is on the right front side of the engine. The pump has a gear that is driven by the front gear group. The pump supplies coolant to the inlet of the oil cooler (13).The oil cooler outlet (12) supplies the right side of the cylinder block and the coolant supply line (11), that is to the water-cooled exhaust pipe (6).Coolant exits the water-cooled exhaust pipe (6) and enters the back of the cylinder heads at (7).Coolant is supplied to the turbocharger at (1) and returns to the radiator from the turbocharger at (2).The coolant that flows into the cylinder block flows around the cylinder liners and into the cylinder heads. As the coolant flows through the cylinder block, the design of the coolant jacket causes the coolant flow to increase velocity around the cylinder liners. The design ensures better cooling efficiency as the coolant passes by the liners. The coolant is pumped through the top deck of the cylinder block into the cylinder heads. The coolant flows through passages around the valves, ports, and combustion chamber of the cylinder head.Coolant from the block exits the cylinder heads at (3) and (8) to supply the coolant temperature regulator housing (4).The temperature regulators control the direction of the coolant flow according to the coolant temperature.Until the coolant achieves normal operating temperature, the coolant flows back to the jacket water pump (14) via the bypass tube (9).When the coolant achieves normal operating temperature, the coolant flows to the radiator via the outlet for coolant to radiator (5).Coolant from the radiator returns to the water pump inlet via a tube at inlet (15).Note: The water temperature regulators are necessary to maintain the correct engine temperature. If the water temperature regulators are not installed in the system, there is no mechanical control. Most of the coolant will take the path of least resistance through the bypass tube. This condition will cause the engine to overheat in hot weather. The small amount of coolant that goes through the radiator in cold weather will not allow the engine to achieve normal operating temperatures. The water temperature regulators control the minimum temperature of the coolant. The radiator or the heat exchanger controls the maximum temperature of the coolant.Separate Circuit System
Illustration 2 g06505461
(1) Aftercooler
(2) Tube for the coolant return from the aftercooler to the thermostatic valve
(3) Tube for the coolant supply to the aftercooler
(4) Outlet for coolant to the radiator
(5) Thermostatic valve housing
(6) Bypass tube
(7) Auxiliary water pump
(8) Tube to the coolant tank
(9) Coolant return from the radiator to the jacket water pump inletThe auxiliary water pump (7) is on the left front side of the engine. The pump has a gear that is driven by the front gear group. The pump supplies coolant to the inlet of the aftercooler (3).Coolant exits the aftercooler at (2) and supplies the thermostatic valve housing (5).The thermostatic valve control the direction of the coolant flow according to the coolant temperature.Until the coolant achieves normal operating temperature, the coolant flows back to the auxiliary water pump (7) via the bypass tube (6).When the coolant achieves normal operating temperature, the coolant flows to the radiator via the outlet for coolant to radiator (4).Coolant from the radiator returns to the water pump inlet via a tube at inlet (9).