The use of this system provides increased power and torque of the engine, fuel efficiency and reduced harmful emissions.
The regulated parameters of the mechanism operation include:
- valve opening (closing) moment;
- valve opening time;
- valve lift height.
In aggregate, these parameters make up the phases of gas distribution – the duration of inlet and outlet cycles, expressed by the angle of rotation of the crankshaft relative to the “dead” points. The distribution phase is determined by the shape of the cam of the camshaft affecting the valve.
Different motor operating modes require different values for it. For example, at low engine speeds, the distribution phases must have a minimum duration (“narrow” phases). At high rpm, on the contrary, they should be as wide as possible and at the same time overlap the inlet and outlet cycles (natural exhaust gas recirculation).
The cam of the camshaft has a certain shape and cannot simultaneously provide narrow and wide phases. In practice, the shape of the cam represents a compromise between high torque at low speeds and high power at high crankshaft speeds. This contradiction is precisely what resolves the change system.
Depending on the adjustable parameters, the following methods of variable gas distribution phases are distinguished:
- rotation of the camshaft;
- using cams with different profiles;
- changing the height of the valve lift.
The most common systems are those using camshaft rotation include VANOS (Double VANOS) from BMW, VVT-i (Dual VVT-i), Variable Valve Timing with intelligence from Toyota, VVT, Variable Valve Timing from Volkswagen and others.
The principle of operation of these systems is based on the rotation of the camshaft, which achieves an early opening of the valves in comparison with the original position.
How much does it cost to replace Cam phasers on f150?
This kind of replacement can be quite costly, especially if you don’t know exactly what kind of malfunction you have. In this case, you can be charged $2000 just to get the malfunction fixed. However, if you ask specifically for a phaser replacement, you will pay somewhere from $550 to $850.
Do cam phasers need to be replaced?
Gas distribution phase change system (generally accepted international name Variable Valve Timing, VVT) is designed to regulate parameters of gas distribution mechanism operation depending on engine operation modes. The use of this system provides increased power and torque of the engine, fuel efficiency and reduced harmful emissions. The need to change the phase is due to the peculiarities of the internal combustion engine, which is expressed in the fact that at different modes of its operation, for example, at idling speed, high speed and low load and at high load, the gas distribution phase should be different.
The solution to this problem was not so easy, but the solution was still found in the form of phase converters. The sprocket timing is controlled by the cam phase, which is a component of the sprocket drive pinion (or sprockets). It uses oil pressure to change the time and rotates the relative position of the cam by means of hydraulic pistons, screw gears, vane or vane rotor.
Due to their design they are impossible to repair, so the only way is to replace phasers with the new ones. Also, it is better to swap the timing chains and guides as well when replacing them.
How much does it cost to replace a 5.4 engine?
The Ford Triton 5.4 version of the atmospheric engine with 24 valves replaced the less powerful 16 valve version in 2004 and was designed for large Ford SUVs and pickups: Expedition, F150, Triton. The Ford Triton range of engines was produced until 2010. The engine blocks for these engines were made of both aluminum and cast iron. V-shaped arrangement of 8 cylinders of 5.4L Triton engine is most suitable for undercover space. The Ford Expedition engine is long, unlike the “square” 4.6L Triton version. This allows for smoother and more powerful performance. The Ford F150 5.4 cylinder heads have only one camshaft each. 2 valves are at the inlet, 1 at the outlet. Degree of compression 9.8 to 1 allows the use of gasoline with octane number 92, which helps to save on fuel.
The cost of replacement depends on the amount of work. Usually, it can cost you somewhere from $2,500 to $4,000 including the parts.
What are the symptoms of a bad cam phaser?
Usually worn-out ones produce loud and rough idle. Often you can hear the sound as if something is knocking. In some cases, the noise is not caused by them, but by cam bearings that are worn out, so it is better to diagnose the car to find out the malfunction.