0382904 JOHNSON CARBURETOR BODY,Plug & throttle valve

The 1673C 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 1940 lbs. (880 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. Injection for each cylinder begins before the piston reaches top center on the compression stroke.A hydra-mechanical governor controls the fuel injection pump out-put to maintain a constant engine RPM under varying work loads. When the engine is being started, a speed limiting device in the governor limits engine speed until engine oil pressure builds up to a safe operating pressure.The engine is of overhead valve design, having one inlet and one exhaust valve for each cylinder. The camshaft, geared and timed to the crankshaft, actuates rocker arms and valves through mechanical lifters and push rods. The timing gears are located on the front of the engine.The starting system is direct electric and uses a 24-volt starting motor. A 12-volt starting motor is optional.Engine coolant 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 SCHEMATICThe fuel system is a pressure-type with a separate injection pump for each engine cylinder. The engine driven gear-type fuel transfer pump draws fuel from the tank through a primary fuel filter. The transfer pump forces the fuel, from the tank, through the main fuel filter. The capacity of the fuel transfer pump is so great that a bypass valve controls the pressure of the fuel. The excess fuel through the bypass valve returns to the fuel tank.The controlled pressure fuel from the main filter fills the fuel manifold in the fuel injection pump housing. The fuel in the manifold supplies the fuel injection pumps. Each fuel injection pump meters and forces the fuel, at the correct instant, through a line to the fuel injection valve in the precombustion chamber of the engine cylinder. The pressure of the fuel in the line opens the fuel injection valve which atomizes the fuel entering the precombustion chamber. The piston compressed air in the engine cylinder ignites the fuel spray.Fuel Injection Pumps
Fuel manifold (1) supplies filtered fuel from the fuel transfer pump through each inlet port (2) to each injection pump.The fuel injection pumps, one for each engine cylinder, are installed in the fuel injection pump housing. A camshaft (9), in the housing, is timed with and driven by the engine crankshaft. The camshaft lobes, one for each injection pump, operate lifter (8) and pump plunger (5) in each injection pump. A spring (6) on each lifter forces the lifter against a camshaft lobe.
FUEL INJECTION PUMP HOUSING AND PUMP CROSS SECTION
1-Fuel manifold. 2-Inlet port. 3-Check valve. 4-Gear. 5-Pump plunger. 6-Spring. 7-Fuel rack. 8-Lifter. 9-Camshaft.A gear (4) locked on each pump plunger (5) is in mesh with fuel rack (7). The movement of the fuel rack rotates the gears and pump plungers which meter and inject the fuel into the engine cylinders. The engine governor controls the movement of fuel rack (7).Fuel Injection Valves
A fuel injection valve in each precombustion chamber (8) for each engine cylinder atomizes the fuel, from the fuel injection pumps, so the fuel sprays into the precombustion chamber.
FUEL INJECTION VALVE IN PRECOMBUSTION CHAMBER
1-Fuel line connector nut. 2-Seal. 3-Valve assembly body. 4-Valve installation nut. 5-Seal. 6-Nozzle assembly valve. 7-Glow plug. 8-Precombustion chamber.Glow Plugs
Glow plugs are used to help ignite the fuel when an engine is started in cold temperatures. Glow plug (7), in each precombustion chamber (8) is an electric heating element. Turning the heat switch ON for approximately a minute, before starting the engine, will heat each glow plug. The compression in the engine cylinders plus the high temperature of the glow plugs promotes easy engine starting in cold temperatures.Governor
The accelerator pedal is linked to the control lever on the engine governor. The operation of the governor controls the amount of fuel necessary for the engine to maintain the accelerator selected engine RPM even when the load changes.The hydra-mechanical governor has engine driven governor weights (12), governor spring (5), a hydraulic valve (13) and piston (14). The valve and piston are connected to rack (17) in the fuel injection pump housing. The engine lubricating oil pump supplies pressure oil through passage (16) and around sleeve (15) for the hydraulic operation of the governor. The accelerator pedal controls only the compression of governor spring (5). The compressed spring force always pushes to increase the supply of fuel to the engine while the centrifugal force of the engine driven governor weights are always pulling to decrease fuel to the engine. The governed RPM of the engine is when these two forces balance.
HYDRA-MECHANICAL GOVERNOR (Typical Example)
1-Collar. 2-Speed limiter plunger. 3-Lever assembly. 4-Seat. 5-Governor spring. 6-Thrust bearing. 7-Oil passage. 8-Drive gear (weight assembly). 9-Cylinder. 10-Bolt. 11-Spring seat. 12-Weights. 13-Valve. 14-Piston. 15-Sleeve. 16-Oil passage. 17-Fuel rack. The governor valve is shown in the position when the force of the weights and the force of the spring are balanced.When engine load increases, engine RPM decreases and revolving weights (12) slow down. The weights move toward each other and