| Valeo’s electromagnetic
valvetrain could be in series production by 2012. The Tier one has an
advanced development programme with a global OEM and is talking with three
more.
Known as “e-Valve”, the system provides camless valve control.
It dispenses with the throttle valve and provides fully variable valve
timing – and duration. The increased control and lower pumping losses
can boost fuel economy by 20 per cent and low-end torque by 15 per cent.
Valeo marketing and business development director Derek de Bono said:
“The initial target is big gasoline V8s. OEMs want to keep them
but really need to reduce their fuel consumption.”
Valeo’s system will compete with other advanced valvetrains soon
to enter the market. Fiat Powertrain Technology’s “Multiair”
electrohydraulic variable valvetrain starts production in 2009. INA’s
‘UniAir’ system goes into production at around the same time.
Fully camless versions exist but the first production applications replace
inlet cams only. “Our cost analysis shows that 80 per cent of the
system’s gain is on the intake side, for half the cost,” said
de Bono. “We couple it to a hydraulic system for cylinder deactivation
on the exhaust side.”
As OEMs increase efforts to cut fleet CO2, the e-Valve system will have
to compete with other fuel-saving technologies such as stratified-charge
direct injection. Both systems add cost and complexity but Valeo believes
it offers benefits other than gains in fuel efficiency and performance.
Group vice-president for R&D Martin Haub said: “This system
can be used with any grade of fuel – you don’t need low-sulphur
gasoline.” Lean NOx catalysts, needed for lean-burn engines, are
poisoned by high sulphur levels found in some gasoline
fuel blends.
Downsized four-cylinder engines will follow, said Valeo. The supplier
has worked on noise, consumption and robustness over the past five years.
New control algorithms address noise, slowing down the valves at the end
of travel. Using magnets and springs to operate the valves has cut power
consumption by a factor of ten.
© Automotive Engineer, 2007 |
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