BABY J
10-03-2009, 09:21 AM
http://3.bp.blogspot.com/_VyTCyizqrHs/SbOWRcygZsI/AAAAAAAADCc/u_FFPN_ClL0/s400/multiair1.jpg
The operating principle of the system, applied to intake valves, is the following: a piston, moved by a mechanical intake camshaft, is connected to the intake valve through a hydraulic chamber, which is controlled by a normally open on/off solenoid valve.
When the solenoid valve is closed, the oil in the hydraulic chamber behaves like a solid body and transmits to the intake valves the lift schedule imposed by the mechanical intake camshaft.
When the solenoid valve is open, the hydraulic chamber and the intake valves are de-coupled; the intake valves do not follow the intake camshaft anymore and close under the valve spring action.
.......
The first new engine to be equipped with MultiAir will be the 16-valve 1.4 litre family of naturally aspirated and turbocharged engines, and the first car to go on sale with MultiAir installed will be the Alfa MiTo at the end of 2009. Its second application will be as an integral part of a new two cylinder engine family.
.......
Low RPM torque is improved by up to 15 per cent through early intake valve closing strategies that maximise the air mass trapped in the cylinders. Elimination of pumping losses brings a 10 per cent reduction in fuel consumption and CO2 emissions, both in naturally aspirated and turbocharged engines with the same displacement. Optimum valve control strategies during engine warm-up and internal exhaust gas recirculation, realised by reopening the intake valves during the exhaust stroke, result in emissions reductions ranging from 40 per cent for unburnt hydrocarbons and carbon monoxide (HC/CO), and up to a 60 per cent cut in oxides of nitrogen, (NOx).
http://4.bp.blogspot.com/_VyTCyizqrHs/SbOWsQJxkuI/AAAAAAAADCk/qbOU_HcxSfM/s400/multiair2.jpg
http://nextbigfuture.com/2009/03/fiats-multi-air-engine-breakthrough-for.html
The operating principle of the system, applied to intake valves, is the following: a piston, moved by a mechanical intake camshaft, is connected to the intake valve through a hydraulic chamber, which is controlled by a normally open on/off solenoid valve.
When the solenoid valve is closed, the oil in the hydraulic chamber behaves like a solid body and transmits to the intake valves the lift schedule imposed by the mechanical intake camshaft.
When the solenoid valve is open, the hydraulic chamber and the intake valves are de-coupled; the intake valves do not follow the intake camshaft anymore and close under the valve spring action.
.......
The first new engine to be equipped with MultiAir will be the 16-valve 1.4 litre family of naturally aspirated and turbocharged engines, and the first car to go on sale with MultiAir installed will be the Alfa MiTo at the end of 2009. Its second application will be as an integral part of a new two cylinder engine family.
.......
Low RPM torque is improved by up to 15 per cent through early intake valve closing strategies that maximise the air mass trapped in the cylinders. Elimination of pumping losses brings a 10 per cent reduction in fuel consumption and CO2 emissions, both in naturally aspirated and turbocharged engines with the same displacement. Optimum valve control strategies during engine warm-up and internal exhaust gas recirculation, realised by reopening the intake valves during the exhaust stroke, result in emissions reductions ranging from 40 per cent for unburnt hydrocarbons and carbon monoxide (HC/CO), and up to a 60 per cent cut in oxides of nitrogen, (NOx).
http://4.bp.blogspot.com/_VyTCyizqrHs/SbOWsQJxkuI/AAAAAAAADCk/qbOU_HcxSfM/s400/multiair2.jpg
http://nextbigfuture.com/2009/03/fiats-multi-air-engine-breakthrough-for.html