Fiat MultiAir Engine
With the constant talk of electric vehicles being the next big thing, it's interesting to see how much development is still being done on the good old internal combustion engine, the Fiat MultiAir engine is a good example.
The Fiat MultiAir Engine, uses a solenoid valve to control oil flow to a hydraulic lifter that actuates the intake valve. The mechanical cam actuating the valves uses a high performance profile. During periods when high performance operation is necessary, the solenoid valve is closed, the hydraulic lifter is locked in place and the mechanical cam is followed yielding maximum performance. During all other periods, from warmup to idling to low speed and everywhere else in between and all through the rpm range, the solenoid valve can be opened at varying times for varying durations to give exactly the engine performance required.
The intake valve, when not directly coupled to the cam, closes using spring pressure with final closure controlled by a dedicated hydraulic brake which ensures a precise soft landing.
Valve control within each stroke
The solenoid valve can vary within each piston stroke, allowing the cam to begin opening the valve early, for instance, then partially allowing oil to flow to keep the valve from opening as far as it otherwise would if following the cam profile exactly. This process allows precise, cylinder by cylinder air flow control to give just the right performance called for with the lowest emissions possible.
Applicable to multiple engine types and fuels
Since this technology applies to valve opening it's widely applicable, it can be used in both spark ignition and diesel engines, normally aspirated or forced induction and with a variety of fuels.
25% better fuel economy and lower emissions
Fiat points to a 25% increase in fuel economy due to greatly increased engine efficiency allowing smaller engines for the same power output plus:
Optimum valve control strategies during engine warm-up and internal Exhaust Gas Recirculation, realized by reopening the intake valves during the exhaust stroke, result in emissions reduction ranging from 40% for HC / CO to 60% for NOx
First application of the technology will be on a 1400cc 16 valve 4 cylinder and then a 900cc 2 cylinder, the sort of engine sizes you might find in a motorcycle. Hmm ...
The precise control now possible of what was once an almost purely mechanical function means the internal combustion engine has a long way to go before it leaves the scene and most of us around here, I think, are pretty happy about that. Very neat technology, I like it!
Link: Fiat via Next Big Future
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{ 16 comments… add yours below ... }
Nice. The ECU/control package may be a bit difficult to incorporate in a motorcycle, but nothing is impossible.
Hmm…use this and slap on a BMW style variable runner length intake. Maybe cogeneration for all the electric generation and run all the accessories and oil pump off of the electric power (gains at least another 6%). Then slap on electrical generating dampers on the shocks and regenerative breaking dumped back into kinetic energy with a small motor and your cycle efficiency would blow most things away. Plus with a bit of non-track allowed aero this could be awesome. I digress.
Love the technology.
Peace.
It is simple enough to work, cheap enough to mass produce, and the benefits are tangable enough to be desirable. Let’s do it. I’ll buy one. Mark.
We are innundated with “Happy Planet” news of alternative fuel and electric vehicles. While the theory may be nice, two basic problems abound:
1. The “alternative fuels” cost more per BTU than fossil fuels.
2. The “recharge” time of hours cannot offset 5 minutes in a service station.
Until these basic things are solved, the answer is to try and make the internal combustion engine more efficient. There is lots of room for improvement too since even the best engines only use 30 – 35% of the latent energy in the fuel. The rest is wasted in heat …. and mechanical politics (constant reversal of direction).
If indeed, this system can achieve a 25% increase in efficiency without a lot of expensive gadgetry, it certainly has a bright future.
Pretty clever these Fiat/Ferrari engineers …..
This is an electro-hydraulic version of BMW’s Valvetronic system they pioneered on their car engines back in 2001. It improves efficiency by getting rid of the throttle plate and removing the pumping losses that causes. It is an efficient system but it took BMW a few years to get the bugs out of it.
This is just a more precise version of Honda’s VTEC, which was developed in the 80’s. Which funny enough, was originally developed for small displacement motorcycle engines.
There is nothing new under the sun, The refinment and manufacturing of these ideas is what will keep the IC engine alive for the forseeable future. Keep an eye open for the electric valve actuators, They also offer infinent control of intake and exhaust events. Chrysler is very near production of its Electric Valve Engine, Lets hope they get it to market before the tech is stolen/copied by another manufacturer,
Ree,
Having first laid eyes on it today, it looks to be only similar to VTEC in that it alters valve lift. VTEC uses two different cam profiles. This system uses only one cam profile with the rocker position dictating valve lift. This is cool because it allows individual tuning for each cylinder. Neat-O!
Mechanical watches did not “leave the scene” when the quartz watch came along. Indeed some of the most complex and elegant mechanical watches are being made NOW. The same may happen with internal combustion engines if electric cars go mainstream: Increasing complexity and elegance, albeit in a very niche market.
While a good idea, I don’t think it would work in a motorcycle.
Take Honda’s VTEC system in their Honda VFR. It is similar to the Fiat multiair (in fact, a lot simpler and smaller because it’s electromechanically controlled and smaller in overall size), yet it is criticized for providing not many tangible benefits in a sports bike, increased complexity and weight, and for creating a small surge in power in the middle of a turn.
I really don’t see how this system, if applied to a motorcycle, would sidestep all those problems, while adding new ones due to the complexity of hydraulics and ECU control.
EP, Honda has a SOHC VTEC system too, that alters lift at the intake only (like this system).
isnt this also alot like wat yamahas exup valve does on th exhaust?
I like the idea and innovation behind it, but after driving two different Fiat automobiles (years ago), I’m not sure I could actually purchase anything built by them. Too many things breaking – and me saying, “Fix It Again Tony!”
Sounds like an active version of the ol’ Rhoads lifters.
Interesting technology ….. carry it to the logical conclusion which is no camshaft at all.
Computer opens valves with hydraulic or HP air actuators = optimum fuel and air curves.
OMMAG,
or you could just make it a direct injection two stroke (http://www.leftlanenews.com/lotus-omnivore.html) and forgoe cams and valves altogether.
Good point ep!
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