0214894 EVINRUDE *DECAL 135

The 1674 Diesel Truck Engine is a 638 cu. in. (10.5 liters) displacement, 4-stroke cycle, six cylinder, turbocharged, diesel engine. The cylinder bore is 4.75 in. (120.6 mm) and the piston stroke is 6.00 in. (152.4 mm). The firing order is 1-5-3-6-2-4. The engine weighs approximately 2280 lbs. (1.034 kg) without coolant or oil.Inlet air, filtered by a dry-type air cleaner, is compressed by a turbocharger before entering the engine cylinders. The turbocharger is driven by the engine exhaust.A plunger and barrel-type fuel injection pump meters and pumps filtered fuel to a precombustion chamber for each cylinder. The fuel is delivered to the precombustion chamber under high pressure.A hydraulic governor controls the fuel injection pump out-put to maintain a constant engine RPM under varying work loads. A speed limiting device, in the governor, limits engine speed until engine oil pressure builds up.There are four in-head valves (two inlet and two exhaust) for each cylinder. Two overhead camshafts, and forked rocker arm assemblies, are located in a housing on top of the cylinder head. The forked rocker arm assemblies act as a direct mechanical link between the lobes on the camshafts and the valve stems. The timing gears are located at the rear of the engine.The starting system is direct electric and uses either a 12 or 24-volt starting motor.Coolant for the engine is used to cool the engine lubricating oil. A full-flow temperature regulator, in the cylinder head at the front of the engine, provides for quick engine warm-up, and allows free circulation of coolant after operating temperature has been reached.Lubrication for the engine is supplied by a gear-type pump. The pump provides full pressure lubrication to the engine internal and external parts.The lubricating oil is both cooled and filtered. Bypass valves in the oil cooler assembly provide unrestricted flow of lubricating oil to the engine parts when oil viscosity is high or, if either the oil cooler or the oil filter element should become clogged.Fuel System
FUEL SYSTEM COMPONENTS
1. Fuel injection valves (six, located in cylinder head, under valve cover). 2. Fuel injection pump. 3. Fuel priming pump. 4. Vent valve. 5. Fuel filter base and final fuel filter. 6. Fuel injection pump housing. 7. Fuel transfer pump.The fuel system is a pressure type with a separate injection pump and injection valve for each cylinder. Fuel is injected into a precombustion chamber, not directly into the cylinder.A transfer pump supplies fuel to a manifold in the injection pump housing. Before fuel is delivered to the manifold, it is filtered by a primary filter that removes dirt particles, and later by a final filter that removes more minute particles.The transfer pump can supply more fuel than is required for injection, so a bypass valve is built into the pump. The valve limits the maximum pressure within the supply system.The injection pumps receive fuel from the manifold and force it under high pressure to the injection valves. The injection valves spray atomized fuel into the precombustion chambers.An air vent valve in the system permits removal of air. Air is removed by opening the valve and pressurizing the fuel system. The system can be pressurized by using the priming pump. The vent valve must be open until a stream of fuel, without air bubbles, flows from the vent line.Fuel Injection Pump Operation
The injection pump plungers and the lifters are lifted by lobes on the camshaft and always make a full stroke. The lifters are held against the cam lobes by springs.
FUEL INJECTION PUMP
1. Check valve. 2. Inlet port. 3. Fuel manifold. 4. Gear segment. 5. Pump plunger. 6. Spring. 7. Fuel rack. 8. Lifter. 9. Camshaft.The amount of fuel pumped each stroke is varied by turning the