Comments on: Fiat MultiAir Engine – Better Mileage, Lower Emissions http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/ Motorcycle News for Positive People Fri, 25 May 2012 21:03:18 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: todd http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/#comment-270996 todd Wed, 17 Feb 2010 00:41:59 +0000 http://thekneeslider.com/?p=4740#comment-270996 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 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

]]> By: GWINDOW http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/#comment-270993 GWINDOW Tue, 16 Feb 2010 23:02:57 +0000 http://thekneeslider.com/?p=4740#comment-270993 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. 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.

]]> By: OMMAG http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/#comment-219650 OMMAG Thu, 12 Mar 2009 22:35:53 +0000 http://thekneeslider.com/?p=4740#comment-219650 Good point ep! Good point ep!

]]> By: ep http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/#comment-219494 ep Thu, 12 Mar 2009 14:51:29 +0000 http://thekneeslider.com/?p=4740#comment-219494 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,

or you could just make it a direct injection two stroke (http://www.leftlanenews.com/lotus-omnivore.html) and forgoe cams and valves altogether.

]]> By: OMMAG http://thekneeslider.com/archives/2009/03/10/fiat-multiair-engine-better-mileage-lower-emissions/#comment-219354 OMMAG Thu, 12 Mar 2009 03:10:39 +0000 http://thekneeslider.com/?p=4740#comment-219354 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. 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.

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