Design features of the F16D and F18D engines

For the Chevrolet Cruze, two 16-valve gasoline engines are offered: the F16D 1.6 liter (82 kW/112 hp) and F18D 1.8 L (103 kW/140 hp), equipped with a variable valve timing system (WT) intake and exhaust valves, as well as a system for changing the length of the intake pipe channels. This subsection describes the F16D engine in detail. Design features of the F18D engine are described in a separate subsection. Details and units of the F16D engine are shown in fig. 5.1.




cylinder head both engines are made of aluminum alloy according to the transverse cylinder scavenging pattern (inlet and outlet ports are located on opposite sides of the head), Valve seats and valve guides are pressed into the heads of the block. The intake and exhaust valves have one spring each, fixed through the plate with two crackers. The camshafts directly act on the valves through hydraulic lifters, which simultaneously perform the function of pushers.

Cylinder block engines are a single casting that forms the cylinders, the cooling jacket, the upper part of the crankcase and five crankshaft bearings made in the form of crankcase baffles. The block is made of special ductile iron with cylinders bored directly in the body of the block. The main bearing caps of both engines are machined complete with blocks and are not interchangeable. Cylinder blocks have special lugs, flanges and holes for attaching parts, components and assemblies, as well as channels of the main oil line.

Crankshaft, forged from special steel, rotates in main bearings with thin-walled steel liners with an anti-friction layer of aluminum-tin alloy. The axial movement of the crankshaft is limited by special flanges made on the middle main journal and resting on the shoulders of the thickened middle main bearing shells.

Pistons made of aluminum alloy. On the cylindrical surface of the piston head there are annular grooves for two compression rings and one oil scraper ring, the latter consisting of three sections. The engine pistons are additionally cooled by oil supplied through a hole in the upper head of the connecting rod and sprayed onto the piston bottom.


piston pins installed in the piston bosses with a gap and pressed with an interference fit into the upper heads of the connecting rods, which are connected with their lower heads to the connecting rod journals of the crankshaft through thin-walled liners, similar in design to the main ones.

connecting rods steel, forged, with an I-section rod.

Lubrication system combined.

Crankcase ventilation system closed type does not communicate directly with the atmosphere, therefore, simultaneously with the suction of gases and gasoline vapors, a vacuum is formed in the crankcase at all engine operating modes, which increases the reliability of various engine seals and reduces the emission of toxic substances into the atmosphere. The ventilation system includes valve 3 (pic. 5.2), ventilation hose 2, inlet pipe 1 and a hose connecting the ventilation system to the diffuser of the throttle assembly.



Under the action of vacuum in the inlet pipeline 1, crankcase gases are sucked through the channel in the engine block into the cavity under the cover of the gas distribution mechanism, from where they enter the intake pipeline 1 through the valve 3 and the ventilation hose 2, where they mix with the air supplied to the engine. The resulting gas mixture, together with the fuel, enters the engine cylinders and burns.


In some cases (for example, in case of severe wear of the cylinder-piston group or prolonged operation of the engine with a high load) the throughput of the ventilation system is insufficient. In this case, part of the crankcase gases is diverted to the throttle assembly, from where it is fed into the engine cylinders for combustion.

The main element of the system is valve 3. When the throttle is fully open, when the vacuum in the intake pipeline is small, the valve is fully open under the action of the spring built into it and crankcase gases freely pass into the intake pipeline. With closed throttle (idle mode) the vacuum in the intake pipeline increases, the valve flow area decreases, the flow of crankcase gases into the pipeline is limited and stable operation of the engine is ensured in idling mode.

Cooling system sealed engines, with an expansion tank, consists of a cooling jacket made in casting and surrounding the cylinders in the block, combustion chambers and gas channels in the cylinder head. Forced circulation of the coolant is provided by a centrifugal water pump driven by a crankshaft timing belt. To maintain the normal operating temperature of the coolant, a thermostat is installed in the cooling system, which closes a large circle of the system when the engine is cold and the coolant temperature is low.

Supply system both engines consists of an electric fuel pump in one module with a fuel filter installed in the fuel tank; throttle assembly, fuel pressure regulator, injectors and fuel lines, and also includes an air filter.

Helpful Hints: With some skill and care, many engine and system failures can be fairly accurately identified by the color of the smoke coming out of the exhaust pipe. Blue smoke indicates that oil has entered the combustion chambers, and constant smoking is a sign of severe wear of the parts of the cylinder-piston group. The appearance of smoke during regassing, after prolonged cranking by the starter, after long idling or immediately after engine braking, as a rule, indicates wear on the valve stem seals. Black smoke is a sign of too rich a mixture due to a malfunction of the engine control system or injectors. Blue or thick white smoke with an admixture of moisture (especially after the engine has overheated) means that coolant entered the combustion chamber through a damaged cylinder head gasket. If this gasket is severely damaged, the liquid sometimes enters the oil sump, while the oil level rises sharply, and the oil itself turns into a cloudy whitish emulsion. White smoke (steam) when the engine is cold in wet or cold weather, this is normal.

Quite often you can see a car standing in the middle of a city traffic jam with an open hood, emitting puffs of steam. Overheat. It is better, of course, not to allow this, often looking at the temperature gauge. But no one is immune from the fact that the thermostat, electric fan may suddenly fail, or coolant will simply flow. If you miss the moment of overheating, do not panic and do not aggravate the situation. Overheating is not as bad as its possible consequences. Never immediately turn off the engine - it will get a heat stroke and, possibly, having cooled down, will refuse to start at all. Having stopped, let it idle, while the fluid circulation will remain in the system. Turn on the heater to maximum power and open the hood. If possible, pour cold water over the radiator. Stop the engine only when the temperature has dropped. But never immediately open the cork of the expansion tank: on an overheated engine, a geyser from under the open cork is provided. Take your time, let everything cool down, and you will save the health of the machine and your own health. Almost all instructions for the car contain a recommendation to depress the clutch when starting the engine. This recommendation is justified only in case of starting in severe frost, so as not to waste battery energy on turning the shafts and gears of the gearbox in thickened oil. In other cases, this is just a recommendation so that the car does not move if the gear is switched on due to forgetfulness. This technique is harmful to the engine, since when the clutch is depressed, a significant force is transmitted through it to the crankshaft thrust bearing, and when starting (especially cold) Lubricant doesn't get to it for a long time. The bearing wears out quickly, the crankshaft receives axial play, and starting off begins to be accompanied by strong vibration. In order not to spoil the engine, make it a habit to check the position of the gear lever before starting and start the engine with a tightened «handbrake», without depressing the clutch unless absolutely necessary.