EFFECT OF SPRAY TIME ON FUEL ON LOSS OF COMBUSTION OF NISSAN UD50 DIESEL MOTORS

Automatic timer on the injection pump, with an automatic timer spring or spring, experiencing wear or reduced pressure. As a result of the wear of the automatic timer spring, the fuel spraying time is delayed especially when operating with heavy loads, the motor can not reach normal power even sometimes the motor dies suddenly. The purpose to be achieved in this paper is to find out how much heat loss from combustion due to the delay in spraying fuel. The research was conducted at PT. Salam Pasifik Indonesia Lines Merauke branch. The method used in this writing is based on secondary data. The data taken is data specifications of Nissan UD50 Diesel motor which is the driving motor for heavy equipment, besides that, also data on fuel consumption in normal conditions and fuel consumption when there is a delay in spraying fuel. The calculation results show that the occurrence of slowness in spraying this fuel will have an impact on the amount of heat produced in combustion, with normal conditions the amount of fuel combustion heat is 33633 Kcal / hour, while the amount of fuel combustion due to late spraying is 26936.7 Kcal / hour, which means that there is an energy loss of 6696.3 Kcal / kg or a power loss of around 10.44 HP