Audi re-thinks the piston engine

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8,051
Location
Michigan
What's with the pistons? Those look like they're out of a loop-scavenged 2-stroke engine. I think Fox News really missed the point of the engine, because they attribute its purpose to reducing vibration. The eccentric shaft to the right of the crankshaft makes me think it's a variable compression ratio scheme. Or maybe a Miller (or Atkinson) cycle engine that has different compression and expansion ratios? There are a lot simpler schemes for reducing vibration in 4-cylinder engines than putting rocker arms between the connecting rod and crankshaft. I've seen pistons driving rocker arms before on the Rootes Commer 3-cylinder OP diesel, but that operated at ~2000 rpm. Will this thing run 6000+ rpm?
 
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778
Location
Southeast Michigan
Originally Posted By: A_Harman
What's with the pistons? Those look like they're out of a loop-scavenged 2-stroke engine.
Maybe they're illustrated that way as a red herring to distract people from other details of the design. laugh
 
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13,616
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Frisco, TX
I don't understand why this needs to be a VAG-bashing thread. OP started it to share info on a new design, not to ask what people thought of the brand. It's good to see this site remain civilized and not turn every other thread into bashing brand X. Also, Jeepman backing up the above poster when Jeep itself sits even lower [on that survey] is pretty amusing too.
 
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Nebraska
Originally Posted By: dparm
Also, Jeepman backing up the above poster when Jeep itself sits even lower [on that survey] is pretty amusing too.
 
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Connecticut
Originally Posted By: dparm
I don't understand why this needs to be a VAG-bashing thread. OP started it to share info on a new design, not to ask what people thought of the brand. It's good to see this site remain civilized and not turn every other thread into bashing brand X. Also, Jeepman backing up the above poster when Jeep itself sits even lower [on that survey] is pretty amusing too.
LOL I like my Jeep, but I'm not a Jeep fanboy. I wouldn't buy any of their new vehicles, or pretty much anything made since 2006. I've worked on enough VWs (sister had one, a few significant others had them, etc) to know about them. Mechanics around here won't touch them for a reason.
 
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1,462
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East Mountains, NM
Originally Posted By: A_Harman
What's with the pistons? Those look like they're out of a loop-scavenged 2-stroke engine.
The pistons look like perhaps they are designed to work with some form of rotary valves. Variable compression would be a particularly good idea with direct injection........And Audi has had its problems with conventional intake valve fouling.
 
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pa
new technology can be great but theres usually bugs for a while. the biggest issue today may be the use of CHEAP parts from the lowest bidder!!!
 
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Oregon coast
Originally Posted By: dparm
I don't understand why this needs to be a VAG-bashing thread. OP started it to share info on a new design, not to ask what people thought of the brand. It's good to see this site remain civilized and not turn every other thread into bashing brand X. Also, Jeepman backing up the above poster when Jeep itself sits even lower [on that survey] is pretty amusing too.
Maybe I'm missing something. Where's the bashing here?
 
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43,671
Location
'Stralia
Originally Posted By: leeharvey418
Interesting... the ability to adjust compression ratio is particularly intriguing.
Nissan in the '80s patented and made/tested a ver very similar arrangements, offering variable displacement, variable compression ratio, and an expansion stroke longer than compression (sort of a proper Atkinson that doesn't spit part of the charge back into the intake). The G.A. was VERY similar... http://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/vcr.html
 
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14,746
Location
Central NY
Originally Posted By: leeharvey418
Interesting... the ability to adjust compression ratio is particularly intriguing.
Some older diesels used to have adjustable compression ratios. Well, adjustable in that it could be none or all. In the day of weak starters, they had a compression release to get the engine spinning up, then you'd apply compression again to get it to start.
 
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11,196
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NY Capital District
Originally Posted By: Miller88
Originally Posted By: leeharvey418
Interesting... the ability to adjust compression ratio is particularly intriguing.
Some older diesels used to have adjustable compression ratios. Well, adjustable in that it could be none or all. In the day of weak starters, they had a compression release to get the engine spinning up, then you'd apply compression again to get it to start.
Modern gasoline engines with VVT also technically have "variable compression". Most of them will keep the intake valve open way longer than typical under light throttle, to reduce pumping losses and lower compression ratio.
 
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2,100
Location
Easton, PA
Originally Posted By: jeepman3071
Originally Posted By: dparm
I don't understand why this needs to be a VAG-bashing thread. OP started it to share info on a new design, not to ask what people thought of the brand. It's good to see this site remain civilized and not turn every other thread into bashing brand X. Also, Jeepman backing up the above poster when Jeep itself sits even lower [on that survey] is pretty amusing too.
LOL I like my Jeep, but I'm not a Jeep fanboy. I wouldn't buy any of their new vehicles, or pretty much anything made since 2006. I've worked on enough VWs (sister had one, a few significant others had them, etc) to know about them. Mechanics around here won't touch them for a reason.
Mechanics won't touch a VW or Audi because they can't fix them. The tools necessary to do so cost more than they would make on the repair. It's just like BMW's or MB. Not every one can or wants to fix them but that doesn't mean they are perpetually broken.
 
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2,035
Location
Ontario, Canada
This is another cool idea, executed a bit like Honda's ex-link epicyclic linkage. Fantastic ideas for large stationary engines or gigantic marine engines perhaps (MAN?), yet super-duper impractical, costly and needlessly complex for high volume consumer motoring IMO.
 
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258
Location
Western NY
Originally Posted By: asand1
] Maybe I'm missing something. Where's the bashing here?
Somebody came by and said that since it was a VW product, they'd be testing on the consumer. Someone else came by to concur and said VW was bad. A German car fan came by to tell them they were mistaken and VAG products were super-cool and better than sliced bread. I stopped by to post a JD Power study showing 174 problems per 100 VWs and 147 per 100 Audis, putting them towards the bottom of the reliability ranking (compared to top-ranked Lexus with 71 problems per 100 cars). Then some censorship occurred, apparently, as all of these posts are gone now.
 
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11,660
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NorthEast
Quote:
JD Power study showing 174 problems per 100 VWs
You are not serious, are you? Are you saying on an average, a VW would have 1.75 problems? Once you correct the above, we can then discuss the JD Power study to see how useful of matrix that one is.
 
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10,708
Location
Jupiter, Florida
I think the variable compression ratio is now unnecessary. Direct injection allows amazingly high compression ratio's on lower octane fuel. As mentioned above, variable valve timing also can result in variable compression ratio and variable expansion ratio. Coupled with throttle by wire, battery assist, stop/start and CVT, the efficiency is much improved.
 
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7,180
Location
CT
And being typical VW group they will have 100ft of timing chain on it that will barely make it 100k miles than shoe horn that puppy against a fire wall and cover it with wires and plastic parts that snap!
 
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