Check it out. GM's been working on a compression ignition gasoline engine. They're showing it off at their Milford Proving Grounds today. The short story is similar power to current gas motors, less fuel.
Link to Article
Link to Article
GM showing off compression-ignition gas engine
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Audi,Toyota and host of other manufactures have been working on this for some time. It is just a matter of public or gorverment demand to force it into production. The cost is like anything if you are makeing them by the millions the cost would come down.
Kestas
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I read this engine will have variable-compression ratio. The last time I read of this technology, it means moving the crankshaft up and down. I'm leery of any new technology that makes things complicated, which also generally makes it less reliable (and more $$$ to fix).
If I am reading correctly...The article indicates that a flameless combustion process is used and that all of the fuel is ignited at once.
Not being skeptical here.
If true this is more revolutionary than evolutionary IMHO.
Rickey.
Not being skeptical here.
If true this is more revolutionary than evolutionary IMHO.
Rickey.
"There's so many different ways to approach fuel efficiency. It doesn't have to come through one huge break through smash hit."
Uh, lets make cars lighter and use smaller engines
Lets offer TDi/CRd/CDi diesel engines
No smash hit needed. Maybe a whack in the head with some common sense
For the first time, the Hummer H3 will be available with a V8 engine.
Yeah, thats the solution
Noone remembers the 2-stroke Orbital?
Uh, lets make cars lighter and use smaller engines
Lets offer TDi/CRd/CDi diesel engines
No smash hit needed. Maybe a whack in the head with some common sense
For the first time, the Hummer H3 will be available with a V8 engine.
Yeah, thats the solution
Noone remembers the 2-stroke Orbital?
Kestas,
I've seen some variable C.R. and variable expansion ratio designs that still have a fixed crank, but with articulated con-rods hooked up to another eccentric shaft, the position of which affects how high the piston rises in the cylinder.
I've seen some variable C.R. and variable expansion ratio designs that still have a fixed crank, but with articulated con-rods hooked up to another eccentric shaft, the position of which affects how high the piston rises in the cylinder.
GM seems to have issues when good working engineering concepts get transfered to production reality!
Quote:
Noone remembers the 2-stroke Orbital?
The same thing happened to it that happened to the 150 mpg carburettors. The oil companies bought them all and has them hidden on the back side of the moon guarded by an army of Pelidian mercinaries.
Some gas engines have direct injection now.
Is this that, or an evolving change?
Is this that, or an evolving change?
In a diesel, fuel droplets burn from the outside first, as light fractions evaporate. What's left gets hotter and hotter until it carbonizes and turns to soot. The HCCI tries to evaporate the fuel completely before compressing it enough to ignite, so there are no hot spots to creat NOx or or cold spots to create CO or soot.
This is that + no spark plugs.
Sounds like a rotary engine to me...pretty cool concept though.
Quote:
"There's so many different ways to approach fuel efficiency. It doesn't have to come through one huge break through smash hit."
Uh, lets make cars lighter and use smaller engines
Lets offer TDi/CRd/CDi diesel engines
No smash hit needed. Maybe a whack in the head with some common sense
For the first time, the Hummer H3 will be available with a V8 engine.
Yeah, thats the solution
Noone remembers the 2-stroke Orbital?
I do and how close Chrysler came to producing a more conventional 2 stroke and .....
Largely agree with your observations here - esp size and weight and if you will , size and weight choices .
However , as unlikely as it sounds in terms of feasibility , if you can make (the big ) pigs fly ...... at least here , ..... thats gonna sell ..... in more ways than one .
Interesting , this is the second botched article I've seen concerning something like this from a normally reliable source in the last month or two .
Well ,anyway ,contrary to the impression conveyed in the linked article this HCCI approach like every other one to date over the last thirty years from the 30 to 45 or so OEMS , Universities , Technical Institutes , etc that I am aware of having worked on this - alternates between sparked ignition and 'heat' ignition . Its not a gasoline fueled diesel in more ways than one .
BTW John Browning , Toyota would not be on that list until relatively recently and they would occupy the last position for the Johnny Come Lately crowd - tied with Hyundai .
Anyway , this technology along with some others concerning conventional IC 4cycle. 'tech' is part of what hybrids and clean diesels alike have to look out for in the interrium distance . Roughly speaking , if you can get 2/3s - 3/4s the benefit for a 1/4 or a 1/3 of the cost ...... now 'stack' a couple together ..... well it sure as heck ain't going to be over until its over .
An interesting example is the MB 1.8L I4 installed in the F700 which is a 'S' class sized vehicle .
- Mercedes-Benz is to unveil a concept car called F700 - a 'radical' proposal for a large luxury car - at the Frankfurt Motor Show.
The F700 will showcase Mercedes' innovative DiesOtto engine, a turbocharged 1.8-litre, four-cylinder unit that combines diesel-style automatic ignition with a conventional petrol spark plug system on start-up and under heavy accelerative demands. This engine is capable of a 235bhp output, but with near-40mpg fuel economy -
Has a huge fat flat torque curve - decent performance as well .
I believe another article puts the Fuel economy number for USA market at 31.5 - 32 mpg .
Soooo ....maybe downsizing won't be so important after all ....unfortunately .
( Just gotta imagine this in something smaller ..... )
Here is an older link from autoblog green that covers alot of the above including GM's HCCI and one perspective on why 2 cycle didn't materialise .
http://www.autobloggreen.com/2007/05/15/...wertrain-resear
Saab is the company responceable for the technology GM is useing for variable compression ratio and they move the head up and down.
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