- 1.4 l R4 16 V (80 hp);
- 1.6 l R4 16V (100 hp);
- 1.6L R4 16V Duratec Ti-VCT with variable valve timing (115 hp);
- 1.8L R4 Duratec-HE 16V (125hp);
- 2.0L R4 16V (145hp);
- and also a 1.8 l R4 16V Duratorq turbodiesel (115 hp).
This book describes only the R4 16V Duratec Ti-VCT engine as it is installed on most of the cars produced, has much in common with the other engines of the family and is the most complex of them.
The R4 16V Duratec Ti-VCT engine with overhead dual five-bearing camshafts has four valves per cylinder. The camshafts are driven by a reinforced toothed belt. The belt tension is provided by a tension roller spring. The valves are driven directly from the camshafts via cylindrical tappets, which also serve as adjusting elements for clearances in the drive.
Cylinder head the cylinder head is made of aluminum alloy with a transverse cylinder scavenging scheme (the intake and exhaust ports are located on opposite sides of the head). Valve seats and guide bushings are pressed into the head. The intake and exhaust valves have one spring each, fixed through a plate with two crackers. The cylinder head is centered on the block with two bushings and attached with ten screws. A shrink-resistant metal-reinforced gasket is installed between the block and the head. In the upper part of the cylinder head, there are five bearing supports for the plain bearings of the two camshafts. The function of the front bearings is performed by the dynamic valve timing system support (see below in this subsection), which simultaneously holds the camshafts from axial displacement. The remaining bearings are detachable. The lower parts of the bearings are made integral with the cylinder head, and the upper parts (covers) are attached to the head with screws. The support holes are machined together with the covers, so the covers are not interchangeable and each of them has a serial number.
Cylinder block it is a single casting made of special high-strength cast iron, forming the cylinders, cooling jacket, upper part of the crankcase and five crankshaft supports, made in the form of crankcase partitions. The cylinders are bored directly in the block body. In the lower part of the block there are five main bearing beds with removable covers attached to the block with bolts. The main bearing covers are machined together with the block and are not interchangeable. In the bearing beds (in the upper parts of the supports) there are outlet openings of oil channels intended for lubrication of the main bearings, and through holes into which ball valves with nozzles are pressed, through which oil is sprayed onto the piston bottoms and cylinder walls. Special bosses, flanges and openings for fastening parts, units and assemblies, as well as channels of the main oil line are made on the cylinder block.
Crankshaft, made of high-strength cast iron, rotates in main bearings equipped with thin-walled steel liners with an antifriction layer. The upper liners, installed in the cylinder block, have a groove on the inner surface and a through slot through which oil flows from the outlet of the oil channel to the ball valve with a nozzle. The lower liners have neither grooves nor slots. The axial movement of the crankshaft is limited by two identical thrust half rings. A flywheel is attached to the rear end of the crankshaft with six bolts. A toothed pulley of the timing mechanism drive and a pulley of the auxiliary units drive are installed on the front end of the crankshaft.
Pistons with a short skirt are made of aluminum alloy. On the cylindrical surface of the piston head there are ring grooves for two compression rings and an oil scraper ring. Six holes in the groove of the oil scraper ring are designed to drain the oil removed by the ring from the cylinder walls. Oil is supplied to the piston pin through two of these holes.
Piston pins tubular section are installed in the piston bosses with a gap and pressed with tension into the upper heads of the connecting rods, which are connected by their lower heads to the connecting rod journals of the crankshaft through thin-walled liners, the design of which is similar to the main liners.
Connecting rods steel, forged, with an I-section rod. The connecting rods are machined together with the caps. In order not to mix them up during assembly, the cylinder ordinal number is applied to the side surfaces of the connecting rods and caps.
Camshafts cast, iron.
The gas distribution mechanism is covered with plastic cylinder head cover. It has an oil separator for the crankcase ventilation system.
Lubrication system combined (for more details, see "Lubrication system").
The oil pan, cast from aluminum alloy, is attached to the cylinder block from below. The oil pan flange is sealed with FORD WSE-M4G323-A4 sealant-gasket. The pan has a hole for draining oil, closed with a threaded plug.
Oil filter full-flow, non-separable, with bypass and anti-drain valves.
Crankcase ventilation system closed, forced, with crankcase gases being removed through an oil separator into the air filter cavity.
Cooling system the engine is sealed, with an expansion tank (for more details, see "Cooling system").
The engine fuel system consists of an electric fuel pump installed in the fuel tank, a throttle assembly, a fine fuel filter and a fuel pressure regulator installed in the fuel pump module, a fuel pressure pulsation compensator, injectors and fuel lines, and also includes an air filter.
Ignition system microprocessor, consists of an ignition coil, high-voltage wires and spark plugs. The ignition coil is controlled by an electronic engine management system unit. The ignition system does not require maintenance or adjustment during operation.
The power unit (engine with gearbox, clutch and final drive) is mounted on three supports with elastic rubber elements: two front ones, which support the main weight of the power unit, and a rear one, which compensates for the torque from the transmission and the loads that occur when the car starts moving, accelerates and brakes.
A distinctive feature of the R4 16V Duratec Ti-VCT engine is the presence of an electronically controlled variable valve timing system (VCT), which dynamically regulates the position of the camshafts. This system allows you to set the optimal valve timing for each moment of engine operation, which, in turn, achieves increased power, better fuel economy and lower toxicity of exhaust gases.
Fig. 5.1. Elements of the variable valve timing system (VCT): 1 – VCT mechanism of the intake camshaft; 2 – VCT mechanism of the exhaust camshaft; 3 – intake camshaft oil seal; 4 – exhaust camshaft oil seal; 5 – electromagnetic valve for regulating the position of the exhaust camshaft; 6 – VCT system support; 7 – electromagnetic valve for regulating the position of the intake camshaft; 8 – exhaust camshaft position sensor; 9 – intake camshaft position sensor; 10 – cylinder head cover; 11 – exhaust camshaft position sensor reference ring; 12 – timing ring of the intake camshaft position sensor
The timing belt drives VCT mechanisms 1 and 2 (Fig. 5.1) of the intake and exhaust camshafts, respectively. The VCT mechanisms, in turn, rotate the corresponding camshafts.
To determine the instantaneous position of the camshafts, sensors 8 and 9 of the camshaft position are installed at the rear end of each of them. On the journals of the camshafts, there are setting rings 11 and 12 of the position sensors.
The front part of the cylinder head is equipped with a VCT system support 6, which simultaneously functions as the front camshaft bearing caps and a holder for camshaft seals 3 and 4. Two electromagnetic valves 5 and 7 are fixed to the support, hydraulically controlling the VCT mechanisms. The electromagnetic valves, in turn, are controlled by the electronic engine control unit.
Fig. 5.2. VCT hydraulic system diagram: 1 – socket for installing the exhaust camshaft position adjustment solenoid valve; 2 – channels connecting the electromagnetic valve and the VCT mechanism of the exhaust camshaft; 3 – channel for supplying oil to the electromagnetic valves from the main oil line of the engine; 4 – VCT support; 5 – channels connecting the electromagnetic valve and the VCT mechanism of the intake camshaft; 6 – socket for installing the electromagnetic valve for adjusting the position of the intake camshaft; 7 – oil supply channel from the main oil line of the engine to the intake camshaft; 8 – cylinder head; 9 – VCT system oil filter; 10 – oil supply channel from the main oil line of the engine to the exhaust camshaft
The oil supplied to the VCT hydraulic system from the main oil line of the engine, in addition to the main oil filter of the lubrication system, is cleaned in the additional filter 9 (Fig. 5.2) of the VCT hydraulic system. Additional cleaning of the oil is required because the flow sections of the electromagnetic valves are very small and contamination particles of 0.2 mm in size can already lead to failure of the VCT system. At the same time, the filter acts as a safety valve, ensuring an uninterrupted supply of oil to the VCT hydraulic system under any circumstances. The filter is non-removable and cannot be replaced.
Fig. 5.3. VCT electromagnetic valve: A – cavity connected by a channel in the caliper with the first working chamber of the VCT mechanism; B – a cavity connected by a channel in the support with the second working chamber of the VCT mechanism; 1 – electromagnet; 2 – valve spool; 3 – annular groove connected by a channel in the support with the second working chamber of the VCT mechanism; 4 – annular groove for oil drainage; 5 – annular groove connected by a channel in the support with the first working chamber of the VCT mechanism; 6 – oil supply hole from the main line; 7 – valve spring; 8 – oil drain hole
The VCT electromagnetic valve, consisting of an electromagnet 1 (Fig. 5.3) and a valve including a spool 2 and a spring 7, according to signals from the electronic engine control unit, supplies oil under pressure from the main line of the lubrication system to the working cavities of the VCT mechanisms or drains oil from these cavities, which leads to mutual movement of the elements of the mechanisms and, as a consequence, to a dynamic change in the position of the camshafts.
When the engine is idling, the electronic engine control unit repeatedly activates the electromagnetic valves for short periods of time in order to clean their elements and channels from any contaminants that may have accidentally gotten into them.
When the power supply to the VCT electromagnetic valves is disconnected, the oil supply holes 6 from the main line and the drain holes 8 are fully open and the VCT mechanisms are set to their initial position. In this case, the engine operates without changing the valve timing.
The VCT system components (solenoid valves and dynamic camshaft position change mechanisms) are precision manufactured units. Therefore, when performing maintenance or repair of the variable valve timing system, only replacement of the system components as a whole is permitted.
NOTE: This section describes engine repair work that is accessible to a novice mechanic: replacing seals, powertrain suspension supports, checking compression, adjusting and grinding valves, etc. A major overhaul of the engine with its complete disassembly requires special equipment and tools, as well as the appropriate technical training of the performer. Therefore, if such repairs are necessary, contact the branded service station.
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