MAIN UNIT STRUCTURE FOR WATER-COOLED ENGINE

摘要

PROBLEM TO BE SOLVED: To improve forming into compactness of an engine and cooling performance of the total unit. SOLUTION: A water pump storage recessed part 54 storing partly or fully a water pump 1 is formed to one sideward in the front surface of a cylinder block 50, a thermostat storage recessed part 53 storing a thermostat is formed adjacently to the water pump storage recessed part 54 in a side wall in one sideward of the cylinder block 1. A heater return passage 51 from a heater 2 communicating with a cooling water passage extended from one side to the other sideward in the front surface of the cylinder block 50 from the thermostat storage recessed part 53 over to the water pump storage recessed part 54 is formed under a water jacket 56 in a cylinder height H1 in the front surface of the cylinder block 50.