RE: Mazda Rotary: Coming Back, But Not Until 2017
Wednesday 10th August 2011
The Mazda rotary engine might be dead for now, a victim of emissions regulations and straitened economic times, but the Japanese company hasn't given up on its quirky tech just yet.
Mazda Rotary: Coming Back, But Not Until 2017
Mark the date in your diaries, Mazda fans...
It looks like we'll have to wait a while for it, however. Mazda has been working on a successor to the RX-8's engine, dubbed the Renesis 16X, since 2007, but with no successor to the RX-8 and plenty of technical challenges to overcome, this new engine isn't likely to find a home before 2017.
Part of the solution will be a radical new ignition system, using powerful yet tiny (11mm) lasers in place of traditional spark plugs. A laser ignition system will, it is claimed, be more fuel-efficient, since it can be run leaner and the timing of the ignition can be timed more finely.
All of which sounds most interesting - it's just a shame we'll have to wait so long to see it. Mind you, 2017 is an apt moment for the rotary motor's reappearance - it will mark 50 years since the Wankel Rotary system made its debut in the NSU Ro80.
Image: Taisyo
Discussion
The better for the likes of us sure. We like cars. We like them for getting around the place quickly and enjoyably. Not so much better for the car manufacturers these days, with more and more legislation being laid down in order to force them not to build cars that people will enjoy, but ones that fulfil a certain set of politically motivated "moral" criteria. Making an interesting sports coupe with an unusual engine doesn't do anything to reduce their CO2 tax burden, or average MPG tax burden or whatever the hell other stupid taxes are being forced on the market by intefering politicos looking to score a cheap point or two with the green lobby.
Hellbound said:
That shouldn't stop them from coming up with some great cars in the meantime though. Not everything has to be about the wankel.
Sometimes I wish they'd just give up the whole rotary thing and say enough is enough, time to start pouring money into mainstream engine design.
But a tiny rev happy engine can mean a very very agile and fast car as we have seen with RX8. If the history taken a differnt path and it was the wankel engine that was inventer first and all the car manufacturers then went on refining it as they did with the piston engine, I reckon the wankel would have none of the issues that plague it right now and only have advantages over teh piston one.Sometimes I wish they'd just give up the whole rotary thing and say enough is enough, time to start pouring money into mainstream engine design.
The trouble is that even a snazzy ignition system with laser beams won't overcome the fundamental drawback of the rotary engine, which is that the shape of the combustion chamber is heavily determined by the required geometry of the rotor/cylinder, and can't really be optimised for combustion.
Ideally, from the point of view of combustion, an engine would have a spherical combustion chamber with the spark plug in the middle. Over-simplistic statement I know, and ignores the need for swirl, and other things. But still, it's hard to design an efficient combustion chamber in a rotary engine, hence the high fuel consumption.
Ideally, from the point of view of combustion, an engine would have a spherical combustion chamber with the spark plug in the middle. Over-simplistic statement I know, and ignores the need for swirl, and other things. But still, it's hard to design an efficient combustion chamber in a rotary engine, hence the high fuel consumption.
A new rotary you say? Why excellent! I just love 100 ft/lbs and 18 mpg... ;-)
Interesting piece of engineering but in the 'real world' horribly compromised. Unless they can reinvent the laws of physics I don't see how they will ever get round the inherent rotary shortcomings.
In a kit car though...hmmm.
Interesting piece of engineering but in the 'real world' horribly compromised. Unless they can reinvent the laws of physics I don't see how they will ever get round the inherent rotary shortcomings.
In a kit car though...hmmm.
The basic problem with a rotary engine is that the suface area of the combustion chamber is too big (relative to the volume) so it will never produce the efficiency of a piston engine of similar output.
isee said:
Hellbound said:
That shouldn't stop them from coming up with some great cars in the meantime though. Not everything has to be about the wankel.
Sometimes I wish they'd just give up the whole rotary thing and say enough is enough, time to start pouring money into mainstream engine design.
But a tiny rev happy engine can mean a very very agile and fast car as we have seen with RX8. If the history taken a differnt path and it was the wankel engine that was inventer first and all the car manufacturers then went on refining it as they did with the piston engine, I reckon the wankel would have none of the issues that plague it right now and only have advantages over teh piston one.Sometimes I wish they'd just give up the whole rotary thing and say enough is enough, time to start pouring money into mainstream engine design.
Snoggledog said:
Won't a laser being fired off several millions of times damage the inside of the engine?
NoLaser damage is really all about power density.... how much energy is focused in that beam. I imagine such a system could use a simple optical element to focus the beam at a particular depth (a focusing system and galvanometers could be used to focus the beam at different depths, different locations to ensure optimum combustion).
the beam will spread out from the focus point and the power density will be much much lower before it reaches anything it can damage. Besides for most metallic surfaces you need quite a decent size laser and you need to coat the surface in a dark colour to allow the laser to couple else it its mostly reflected and scattered.
I mean we did experiments at uni using a 1.5kW infra-red CO2 laser to cut/weld 1.5mm plate.
I imagine these will be much lower power, diode or fibre lasers... they will get the required power density to get to ignition temperature by focusing the beam. Maybe they can over drive... you can for instance massively over drive an LED if you do so for only a minuscule time. like micro seconds.
Laser ignited wankel? 2017? I'll believe it when I see it. 
At the very least sounds costly to service. Modern ignition systems are already expensive to service/replace. Ever had to replace the coil pack/wiring harness on a VW VR6? Imagine how expensive it will be when you have to replace laser tech.
At the very least sounds costly to service. Modern ignition systems are already expensive to service/replace. Ever had to replace the coil pack/wiring harness on a VW VR6? Imagine how expensive it will be when you have to replace laser tech.
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