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I wonder how the bean counters will charge us more for this new less complicated engine. Assuming it gets into production.
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My inner cynic suggests that if it wroks an oil company will buy the patent and bury it. No doubt it has happened before
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Interesting, with any luck Fiats cam-less engine will appear soon too, it uses electromagnetic solenoid operated valves, the technology is very expensive so the rumour is they are going to release a twin cylinder 600CC two valves per cylinder to put in the Fiat 500, this will do something like 80-90mpg. The totally variable valve timing means the valves can be opened to spin the engine up without compression pressure before starting (this would double engine life) as well as the torque/efficiency advantages of having perfect "cam timing" throughout the rev range. The limiting factor at the moment is the low rev-ceiling imposed by this infant technology. There's life left in suck, squeeze, bang, blow yet!
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The limiting factor at the moment is the low-rev ceiling imposed by this infant technology
I know that Formula 1 use pneumatic valve technology in order to increase rev limits on their racing engines. But thats in the quest for more power. I don't suppose it will filter down to engines designed for economy.
I suppose electromagnetic solenoids can only move so fast, one of the reasons they moved to peizo-electric injectors on diesels.
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People often assume F1 engines have pneumatic valve actuation and some think they are cam-less - they're not. The pneumatic valve technology is simply there to hold the valve against the good old fashioned camshaft lobe to eliminate valve bounce and float. In other words it (sometimes) replaces or assists the valve spring.
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>> The limiting factor at the moment is the low-rev ceiling imposed by this infant technology
Infant technologym there was at least one yank car in the 70's running with solenoids. Died out due to cost.
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"Fiats cam-less engine"
Sounds terrific, until you remember that it's Italian and relies entirely on working electrics.. :-)
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Unless it more than doubles efficiency in terms of MPG, it's a dead duck.
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I thought Vauxhall has tried this in a 1.8 HCCI engine.
I could be wrong though.
Apparently the spark plugs existed and the cam had two profiles (normal and HCCI mode).
The engine ran as normal most of the time but under gentle acceleration the spark plugs were not used and the cam changed profile to HCCI settings.
The idea is sound in principle. I just wonder if a cat still has to be fitted strangling a clean engine.
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RE: "Homogeneous charge compression ignition (HCCI) is a form of internal combustion in which well-mixed fuel and oxidizer (typically air) are compressed to the point of auto-ignition."
So it's basically a petrol engine without a spark-plug that runs by pinking? I wouldn't put money on it.
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>>So it's basically a petrol engine without a spark-plug that runs by pinking?
That's not too far from a definition of a diesel engine!
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"That's not too far from a definition of a diesel engine"
Does that mean it won't matter if you put the wrong fuel in..?
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"We've reduced the temperature inside the combustion chamber"
Like water injection, then.. :-)
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I'm sure there'll be some effect[1] - but also there's probably a trade-off - and it's still using fossil fuel - so it's dead before it even starts.
[1] I'm sceptical of the top figure of 30%, but the article does say "up to", which clearly includes the number 0.
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Most manufacturers could produce clean/economical gasoline engines which could meet environmental regulations without catalysts but the emission regulations are worded to make catalysts mandatory-it also reduces the fuel economy;lean-burn technology could see excellent combustion with air/fuel raios of upto 20/1 but to make a catalyst work you need stoichmetric-14.7/1.
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F1 engines normally use nitrogen at high pressures to close the valves instead of springs-less inertia.
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Most manufacturers could produce clean/economical gasoline engines which could meet environmental regulations without catalysts but the emission regulations are worded to make catalysts mandatory-it also reduces the fuel economy;lean-burn technology could see excellent combustion with air/fuel raios of upto 20/1 but to make a catalyst work you need stoichmetric-14.7/1.
Indeed, jc2. Ford were achieving some very impressive fuel economy figures from reworked 1970's engines running carbs in the late 80's (under the brand name of E-Max IIRC). I often wonder what would the result would have been had this research continued until today with modern engine designs, and the ultra-tight level of fuelling control and monitoring afforded by modern engine management systems.
I've always considered catalysts to be a very inelegant solution to the problem. Apart from the notion of cleaning up a dirty engine, they reduce engine efficiency, and the mining of the precious metals used in their construction damages the environment. I've never understood why they were adopted.
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"We've reduced the temperature inside the combustion chamber. When you do that, you reduce the nitrous emissions which means you don't need the catalytic converter. "
And we don't need inventors who havent grasped what a catalytic convertor does. It reduces CO emissions (converting to CO2) and has nothing to do with NOx emissions.
HCCI has been around for a long long time. Its the petrol equivalent of the diesel working on a compression ignition principle. The problem with HCCI is that it is extremely difficult to control the ignition of petrol in such an engine and is very likely many years away before it becomes practical if at all.
VW, Vauxhall et al are working at the R&D level on hybrid HCCI - where the engines occassionally work in HCCI mode, but still rely on conventional spark ignition for the 90% of the time it doesnt work. No plans for production AFAIK
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>>and has nothing to do with NOx emissions.
That's not true.
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"And we don't need inventors who havent grasped what a catalytic convertor does. It reduces CO emissions (converting to CO2) and has nothing to do with NOx emissions."
I wondered about that, too, but '3-way' ones do handle NOx, apparently:
en.wikipedia.org/wiki/Catalytic_converter
I suspect that the woolly wording was more to do with the BBC journo's ignorance than the inventor's...
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"I've never understood why they were adopted"
I think because they had already been adopted in the US, where they provided a quick fix to new EPA regulations, and gave US car-makers an advantage in that the extra fuel consumption was less noticeable on a gas-guzzler, it saved expense on R&D and the extra cost of the Cat made a bigger impact on imported vehicles.
Only a temporary advantage, of course. I have to say that one of the few things on which I ever agreed with Mrs T was her attitude to lean-burn engines, which she wanted instead. Sadly, it was one of the ever fewer things that she didn't get her own way on...
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