Applying the information in this chapter
Chapter 25 describes the repair procedures that are performed on the engine installed in the car, and contains only the technical requirements corresponding to these procedures. Since these procedures are performed on the engine installed in the vehicle, when the engine is removed from the vehicle and mounted on a stand, some of the previous removal steps must be skipped.
Information pertaining to engine/transmission removal and installation and engine repair can be found in chapter 2B. It also contains technical requirements related to these procedures.
General description of the engine
The engine, also known as "Duratec" (used internally by Ford) - 6-cylinder, with a V-shaped arrangement of cylinders, is installed transversely in the front of the car. In this case, the transmission is located on the left side of the engine. The main castings of the engine are made of aluminum alloy, including the block heads. Each cylinder has 4 valves - two intake and two exhaust. The total number of engine valves is 24. A system for changing the intake tract route is installed in the intake manifold, switched using a vacuum. It allows you to optimize the engine torque and power: below 3200 rpm, the engine works efficiently like a 12-valve, and at higher speeds it works like a 24-valve.
The crankshaft is supported by 4 main bearings. The bearing closest to the flywheel/faceplate assembly contains thrust washers on both sides of the bushing to absorb axial forces and provide end play to the crankshaft. The connecting rods are mounted on liners with a horizontal split of the lower heads. The pistons are connected to the connecting rods by means of floating pins, which are fixed in the pistons by elastic rings. Pistons made of aluminum alloy have three rings: two compression and one oil scraper. During the manufacturing process, the cylinders and piston skirts are measured and divided into three sizes. This is necessary to ensure the necessary clearance between the piston and the cylinder. Repair dimensions for subsequent regrinding are not provided.
The intake and exhaust valves are closed by coil springs. The valves are mounted in guides that are pressed into the head of the block in the same way as the valve seat inserts.
Camshafts are driven in pairs by two chains: one for each block head. Each of these shafts acts on the valves through self-adjusting hydraulic lifters. This eliminates the need to monitor and adjust valve clearances. The intake camshaft of the front head of the block is supported by five bearings. The remaining shafts have four bearings each, which are formed by joint boring of the block head and bearing caps (bolted). Therefore, covers are not supplied separately from the block head and it is also impossible to use covers from another engine.
The cooling system pump is bolted to the left end of the cylinder block and is driven by a belt from a pulley mounted on the left end of the front head intake camshaft.
Lubrication is carried out using a pump with an eccentrically mounted rotor, which is mounted on the right end of the crankshaft. This pump draws oil through a strainer located in the sump and delivers oil through a cassette type pop-flow filter mounted outside the engine. On some engines, an oil cooler is installed, mounted on an oil filter support and. thus, the clean oil entering the engine passages is cooled by the main engine cooling system. From the filter, oil enters the cylinder block / crankcase line and then through the channels to the crankshaft main bearings and to the block head.
The engines described in this book are equipped with hydraulic lifters, which work under the pressure of the lubrication system and allow the gap between the camshaft cam and the corresponding valve stem to be automatically compensated. Therefore, adjustment and checking of valve clearances is not required. At the same time, only high-quality oils of a regulated viscosity that meet technical requirements must be used in the engine, and the oil must be changed in accordance with the maintenance schedule. If these instructions are violated, oil channels and hydraulic lifters may become clogged with dirt or deposits of burnt oil particles. As a result, the performance of the system may be reduced. In the worst case, one or more expansion joints may fail, requiring costly repairs.
When starting a cold engine, oil flows to all engine components, and especially to hydraulic lifters, with a slight delay. Therefore, valve components may knock for some time (about 10 sec), after which the noise disappears. This is normal and should not cause concern.
If the vehicle has been sitting for several days, then the valve components may knock for a little longer than usual, as oil drains from the components and bearings located at the top of the engine. In this case, in order not to damage the engine, you should not work at high speeds until all expansion joints are filled with oil and begin to work normally. When the vehicle is stationary, maintain high idle (maximum 2000-2500 rpm) for 10-15 seconds, or until the noise disappears. Do not operate above 3000 rpm until the expansion joints are filled with oil and the noise disappears.
Visitor comments