DETROIT DIESEL Description The V-71 engines (6, 8, 12 and 16 cylinder models) covered by this manual have the same bore and stroke and use many of the same parts. through the injectors, it serves to cool the injectors and carry off any air in the fuel system. Air for scavenging and combustion is supplied by a blower(s) which pumps air into the engine cylinders via the air box and cylinder liner ports. All air entering the blower(s) first passes through an air cleaner or silencer. All cylinder blocks are symmetrical in design thus permitting oil cooler or starter installation on the same side or on opposite sides of the engine, depending upon the installation requirements.
The engines are built with right-hand or left-hand crankshaft rotation. For example, the crankshaft in an RC engine, viewed from the flywheel end, will rotate counterclockwise, the oil cooler will be mounted on the right-hand side of the engine and the starter will be on the left-hand side of the engine (Fig. 2). Full pressure lubrication is supplied to all main, connecting rod and camshaft bearings, and to other moving parts of the engine. A gear-type pump draws oil from the oil pan through an intake screen and delivers it to the oil filter(s) and then to the oil cooler(s).
From the oil cooler(s) the oil flows through passages that connect with the oil galleries in the cylinder block and cylinder heads for distribution to the bearings, rocker arm mechanism and other functional parts. There are eight basic engine models. The letter L or R indicates left or right-hand engine rotation as viewed from the front of the engine. The letter A, B, C or D designates the location of the starter and oil cooler as viewed from the rear (flywheel) end. For the meaning of each digit in the model numbering system, refer to Fig. 2. Coolant is circulated through the engine by a centrifugal type water pump.
Heat is removed from the coolant, which circulates in a closed system, by either a radiator or heat exchanger. Control of the engine temperature is accomplished by thermostats that regulate the flow of the coolant within the cooling system. The engines are normally equipped with an oil cooler, lubricating oil filter(s), fuel oil strainer, fuel oil filter, air cleaner(s) or silencer(s), governor, heat exchanger and raw water pump or fan and radiator, and a starter. Engine starting is provided by either a hydraulic or an electrical starting system.
Fuel is drawn from the supply tank and through a strainer by a gear-type fuel pump, then it is forced through the filter and the fuel inlet manifolds in the cylinder heads to the injectors. Excess fuel is returned to the supply tank via the return fuel manifolds and connecting lines. Since fuel is constantly circulating Engine speed is controlled by a governor. Some engines have a mechanical limiting speed governor, some a mechanical variable speed governor, and other engines use a limiting speed or a variable speed hydraulic governor. The engine application determines which type of governor is used. Page 5