805159 Mercruiser SCREW, (.437-20 x 1.500)

General Information
TYPICAL ENGINE ARRANGEMENTS
1. Fuel priming pump. 2. Turbocharger. 3. Governor. 4. Fuel injection pump housing. 5. Crankcase breather. 6. Fuel filter. 7. Electric starter. 8. Exhaust manifold. 9. Fan and fan drive. 10. Air inlet manifold. 11. Air cleaner. 12. Water pump. 13. Engine oil cooler. 14. Engine oil filter. 15. Oil filler cap. 16. Transmission oil cooler.The 3306 Vehicular Engine is part of a series of 4.75 in. (120.7 mm) bore, 6.00 in. (152.4 mm) stroke in-line engines. This book has information for the six cylinder engine.This engine has 638 cu. in. (10.5 liter) displacement. The firing order is 1,5,3,6,2,4.The starting system is direct electric and uses a 24 volt starter motor. Sleeve Metering Fuel System
Introduction
The Sleeve Metering Fuel System is a pressure type fuel system. The name for the system is from the method used to control the amount of fuel in the fuel injection charge. This system has an injection pump and an injection valve for each cylinder. The injection pumps are in the fuel injection pump housing on the right side of the engine. The injection valves are in the precombustion chambers for PC engines and in adapters in the cylinder head for DI engines.The drive gear for the fuel transfer pump is on the front of the camshaft for the injection pumps. The carrier for the governor weights is bolted to the rear of the camshaft for the injection pumps. The injection pump housing has a bearing at each end to support the camshaft. The camshaft for the sleeve metering fuel system is driven by the timing gears at the front of the engine.The injection pumps, lifters and rollers, and the camshaft are all inside of the pump housing. The pump housing and the governor housing are full of fuel at transfer pump pressure (fuel system pressure).
Diesel fuel is the only lubrication for the moving parts in the transfer pump, injection pump housing and the governor. The injection pump housing must be full of fuel before turning the camshaft.
Fuel System Timing
Injection timing before TC (top center):Sleeve Metering-PC ... 13° 30' 1°Sleeve Metering-DI:Engines with turbocharger ... 23 1°Engines without turbocharger ... 29 1°Fuel Injection Valves
Fuel, under high pressure from the injection pumps, is sent through the injection valves. The injection valves change the fuel to the correct fuel characteristic (spray pattern) for good combustion in the cylinders.The fuel injection valves are installed in the precombustion chambers in engines equipped with precombustion chambers. An adapter takes the place of the precombustion chamber in engines equipped with direct injection. The precombustion chambers or adapters are installed in the cylinder heads.Water Separator
Some engines have a water separator. The water separator is installed between the fuel tank and the rest of the fuel system. For efficiency in the action of the water separator, the fuel flow must come directly from the fuel tank and through the water separator. This is because the action of going through a pump or valves before the water separator lowers the efficiency of the water separator.The water separator can remove 95% of the water in a fuel flow of up to 33 gph (125 liter/hr) if the concentration of the water in the fuel is 10% or less. It is important to check the water level in the water separator frequently. The maximum amount of water which the water separator can hold is 0.8 pt (0.4 liter). At this point the water fills the glass to 3/4 full. Do not let the water separator have this much water before draining the water. After the water level is at 3/4 full, the water separator loses its efficiency and the water in the fuel can go through the separator and cause damage to the fuel injection pump.Drain the water from the water separator every day or when the water level gets to 1/2 full. This gives the system protection from water in the fuel. If the fuel has a high concentration of water, or if the flow rate of fuel through the water separator is high, the water separator fills with water faster and must be drained more often.To drain the water separator, open the valve in the drain line and the valve at the top of the water separator. Let the water drain until it is all out of the water separator. Close both valves.
WATER SEPARATORFuel Flow
System With Siphon Break
SCHEMATIC OF FUEL SYSTEM
1. Governor. 2. Fuel injection pump. 3. Fuel injection pump housing. 4. Fuel bypass valve. 5. Manual bleed valve. 6. Fuel tank. 7. Primary check valve. 8. Fuel supply line. 9. Water separator (attachment). 10. Drain for water separator. 11. Vent for water separator. 12. Fuel filter. 13. Check valve. 14. Fuel priming pump. 15. Check valve. 16. Fuel transfer pump. A. Siphon break orifice.
FUEL SYSTEM INSTALLED
2. Fuel injection pump. 3. Fuel injection pump housing. 5. Manual bleed valve. 12. Fuel filter. 14. Fuel priming pump. A. Siphon break orifice (inside of housing).
FUEL INJECTION PUMP HOUSING AND GOVERNOR
1. Governor. 2. Fuel injection pump. 3. Fuel injection pump housing. 5. Manual bleed valve. 14. Fuel priming pump. 16. Fuel transfer pump.When the engine is running, transfer pump (16) pulls fuel from fuel tank (6), through fuel filter (12), and into channel (17) behind cover (18). From the channel, the fuel goes through check valve (13) into the bottom of priming pump (14), through the priming pump, out check valve (15) and into passage (20) in the housing. The fuel in the passage is the supply for transfer pump (16). The output of the transfer pump goes into housing (3).
SLEEVE METERING FUEL PUMP
17. Channel. 18. Cover for housing.The fuel in the housing is the supply for the injection pumps and the lubricant for all the moving parts in the housing. Fuel can go from the housing in two ways.1. Fuel injection pumps (2) send some fuel to the cylinders during injection.2. Bypass valve (4) keeps the pressure of the fuel in the housing at a maximum of 25 to 32