Launched in 2009, it dispenses with the intake camshaft
In its place there is an electro-hydraulic actuator controlled by the control unit
A little more than ten years ago, Fiat presented a technology for its engines at least creative. He called it Multiair, and its characteristic was that it dispensed with the intake camshaft to offer a hydraulic system with which to better control the amount of air entering the combustion chamber. His debut in 2009 was with the late Alfa Romeo Mito.
A few weeks ago we published an interesting article about a company that had developed a cylinder head that completely dispensed with the camshafts to operate the valves. Instead, there are electronically controlled actuators, a “virtual camshaft” as its creators like to call it. In this way, the valve position can be controlled to the millimeter and millisecond.
It is not the first time that we say that greater restriction to the passage of air In an internal combustion engine, it is located in the valve seat area, so being able to control both the lift, the distribution and the crossover provides a lot of play for motorists to be able to extract more juice from the mechanics. This shows the considerable importance of both the camshaft and the cams themselves.
In today’s case we will talk in a general way about the main technology feature ‘Multiair’, developed by Fiat with the collaboration of Magneti Marelli in the electronic part, and whose main characteristic is none other than having a single camshaft for the exhaust part. It has a trick, and that is that, for its counterpart, the system makes use of a circuit with electro-hydraulic actuators… Activated by an extra cam on the same shaft. In this way, the sole purpose of it is to pump the oil to operate the intake system.
The results are the fruit of extensive research over more than ten years at Fiat’s technology center, on the outskirts of Turin, after an investment close to the 100 million euros.
The real advantage of all this is that the on-board ECU can change parameters and regulation of these actuators –timing ‘and elevation– according to the speed of rotation to obtain optimum combustion, response and efficiency. If we talk about the advantages, they are clear: increase in power and torque between a 10 and 15%, reduction in consumption by 10% and up to 60% in the case of nitrogen oxide emissions.
As an example of operation, the system delays the opening of the valve and reduces lift at times of low throttle stress. In the case of driving at full capacity, the closure is advanced and the lift of the valve is maximum.
It was released on the market in 2009, in the variant with the 1.4-liter, 105-horsepower naturally aspirated gasoline engine of the Alfa Romeo Mito. Since then they have also been seen in other models and brands of the group, from Lancia to Jeep, with powers that in some cases have reached more than 180 horses. Currently, the technology continues in force in the mechanics ” Firefly ” with its third iteration, with variants that have already adopted hybridization.
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