A senior Fiat powertrain exec confirmed to Motor Trend that the Italian automaker’s clever MultiAir valve-control tech will be fitted to Chrysler’s four- and V-6 engine families, and soon.
Chryler Pentastar V 6 Engine
Massimo Fumarola, Fiat Powertrain vice-president of product and key account management, says development work is nearly complete on MultiAir versions of Chrysler’s 2.0- and 2.4-liter fours, and both 3.2- and 3.6-liter versions of the new Pentastar V-6. The engines will be installed in Chrysler brand cars for the North American and European markets (where the 200, 300 and Town & Country will go on sale soon wearing Lancia badges)
MultiAir is a computer-controlled electrohydraulic inlet valve lift and duration control system. It offers the same advantages as BMW’s well-known Valvetronic system, but is even more flexible, as it’s able to control individual cylinders. With inlet valves directly controlling the amount of air entering the engine, the pumping losses involved in sucking air past a conventional throttle butterfly are avoided.
Fiat Multiair Engine
The system is easily adaptable to existing engines. The key component — an alloy block with hydraulic pistons, passages, and electrically controlled bleed valves — can simply bolt on top of an existing head. Fiat Powertrain engineers call this piece simply The Brick.
The first engine to get the MultiAir treatment was an existing 1.4-liter four, introduced in both naturally aspirated and mild turbo forms back in 2009. The same engine, including more powerful turbo versions, has since been installed in Alfa Romeo’s Mito and the new Giulietta, and also will power the American market version of the Fiat 500.
Fiat’s claims for the benefits of MultiAir — power increased 10 percent, low-end torque improved by 15 percent, fuel consumption reduced 10 percent (in both naturally aspirated and turbo flavors) — seem to be delivered in the real world. While Italian magazine tests have confirmed better performance, the consumption picture is a little cloudy, as Fiat introduced a Start/Stop auto engine shutdown system simultaneously.
In Europe, MultiAir’s potential as an enabler of downsizing was too much for Fiat to resist. Last year it launched an engine entirely designed around the tech. TwinAir is a 900-cc in-line two-cylinder turbo that produces 84 horsepower, enough to push the Euro-market Fiat 500 to well past 100 mph on the autostrada and deliver Prius-like numbers in the official European consumption test. Fiat argues that MultiAir plus turbo plus downsizing can deliver fuel economy gains as great as 25 percent. TwinAir appears to prove the point.
There’s no reason why MultiAir shouldn’t work on larger engines. According to Fumarola, the tech has been tested in the past on Ferrari engines. It was only rejected, he explains, because the 7000 rpm ceiling imposed by MultiAir was stifled the Maranello character.
Still, 7000 wouldn’t be a problem for, say, a Hemi V-8. When asked, Fumarola admitted it was technically possible to MultiAir-ate the engine. But he quickly added that he saw little call from the marketplace for more power from the Hemi. But another Fiat source confirmed, confidentially, that development of a MultiAir Hemi is under way…