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
Spartandude says
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.
Mark Shapiro says
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.
Hawk says
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 …..
Richard M says
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.
Ree says
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.
Tin Man 2 says
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,
ep says
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!
WRXr says
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.
Chris says
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.
Chris says
EP, Honda has a SOHC VTEC system too, that alters lift at the intake only (like this system).
Dean says
isnt this also alot like wat yamahas exup valve does on th exhaust?
Claymore says
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!”
Nobody says
Sounds like an active version of the ol’ Rhoads lifters.
OMMAG says
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.
ep says
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.
OMMAG says
Good point ep!
GWINDOW says
MultiAir is not just a better version of Honda’s VVT technology or BMW’s Valvetronic system but rather superior to any other VVT technology on the market. It is the only system which can independently and instantly change the valve timing and opening profile of the valves cylinder by cylinder and stroke by stroke. In other words it can vary from minimal or no opening (idle) to full lift within one engine stroke phase. The biggest merrit of this system however is that it eliminates pumping losses. Any other engine (with or without VVT) constantly wastes 10% of its power by creating a unnecessary pressure drop in the gas manifold (between butterfly valve and cylinder injection valve). The cylinder has to ‘suck’ the air gas mixture into the cylinder creating this pressure drop all the way from cylinder through supply manifold to the butterfly valve. Once the injection valve closes it will just burn the gas trapped inside the cylinder while the created pressure drop in the supply manifold is given away in the following phase. Multiair eliminates the butterfly valve and all associated friction and pumping losses. It directly uses the injection valves to dose the required air-gas mixture going into the cylinder. No more friction and pumping to get air into the cylinder. This is HUGE and unprecedented in internal combustion engine technology.
todd says
GWINDOW, there is value in manifold vacuum; brake boosters, PCV valves, door locks, etc. I guess we can add complexity by powering all these things with something else though. I get the feeling that the point in current automotive trends is to make things progressively more complicated so that problems occur at a greater frequency. In this scenario one is required to visit the dealer more often for repairs.
-todd