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infinity variable compression engine #5227934 10/01/19 08:33 PM
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edwardh1 Offline OP
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how is it working out- sounds complicated to me.


These products are all new every year?? They are a revolution!!! Razor blades, mens shirts, TVs, wiper blades, gutter guards, hearing aids... according to the ads. But also all new last year
Re: infinity variable compression engine [Re: edwardh1] #5227956 10/01/19 09:12 PM
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atikovi Offline
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https://www.infinitiusa.com/infiniti-now/technology/vc-turbo-engine.html

Scotty Kilmer hates it, but he hates every technology less than 20 years old.

Re: infinity variable compression engine [Re: edwardh1] #5227988 10/01/19 10:25 PM
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Number_35 Offline
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I read somewhere that the real-world fuel savings were disappointing, not enough to justify the cost and complexity of the new technology. Put me in Scotty's camp I guess.

Re: infinity variable compression engine [Re: atikovi] #5227992 10/01/19 10:28 PM
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JLTD Offline
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Originally Posted by atikovi
https://www.infinitiusa.com/infiniti-now/technology/vc-turbo-engine.html

Scotty Kilmer hates it, but he hates every technology less than 20 years old.


Then Scottie should like it, the Nissan article says in development more than 20 years. LOL


Lates.
Re: infinity variable compression engine [Re: edwardh1] #5228019 10/01/19 11:51 PM
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GZRider Offline
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"The more they overthink the plumbing, the easier it is to stop up the drain." From Space Shuttles to Nissan Sentra's the words of the galaxies best chief engineer
Montgomery Scott invariably prove to be true when given a long enough time scale.

Re: infinity variable compression engine [Re: edwardh1] #5228063 10/02/19 03:52 AM
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Ws6 Offline
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Seems like a fail compared to other competitors.

Re: infinity variable compression engine [Re: edwardh1] #5228147 10/02/19 07:24 AM
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Cujet Offline
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With Lister CS (cold start) diesel engines, they provided an external knob to raise the compression ratio. It was simply a valve that closed off a small chamber. Very simple and 100% reliable.

It's entirely possible to so something similar with gas engines. Using a device that changes position in the combustion chamber, to lower the compression ratio. The argument that it disrupts the combustion event is in error. Today's direct injection combustion chambers are chock-a-block full of unusual and sharp shapes designed to help direct injection function properly.

Remember spark plug spacers?


People who count on their fingers should maintain a discreet silence.
Re: infinity variable compression engine [Re: edwardh1] #5228338 10/02/19 11:39 AM
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Kestas Online Content
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As Number_35 stated, It's probably cheaper to burn more fuel than deal with the complexity of this design.

The name of the game is not to save gas, it's to make travel from Point A to Point B as inexpensive as possible.

I suspect if the time comes when gas is so expensive that variable compression is economically justified, we'll have moved on to EVs.

Re: infinity variable compression engine [Re: Cujet] #5228347 10/02/19 11:55 AM
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GZRider Offline
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The diesel system is simple and works on pressure dynamics, reducing combustion chamber size by partially obstructing it's volume using a manual valve which in turn raises compression. The Nissan VC works differently, variable compression way of variable stroke depth and an actuator motor. https://www.nissan-global.com/EN/TECHNOLOGY/OVERVIEW/vc_turbo_engine.html

There's a reason even we Nissan/Infiniti enthusiasts joke about Nissan being the Chrysler of Japan.

Re: infinity variable compression engine [Re: edwardh1] #5228348 10/02/19 11:58 AM
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atikovi Offline
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The thing I find interesting in that page is the 8:1 compression is for more power while 14:1 is for efficiency. Pretty much the opposite of established hot rodding practise of higher compression = more power.

Re: infinity variable compression engine [Re: edwardh1] #5228736 10/02/19 06:54 PM
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Variable compression, variable valve lift and timing, variable boost turbo / super charger, etc all have the same goal: maximize fuel economy and power.

Until I see the long term result (i.e. 10 years, 100k miles), I am a bit skeptic. There has to be a reason why nobody else is doing it.


"You keep asking questions PandaBear and you'll end up a vegetarian like my wife" - Camu Mahubah
Re: infinity variable compression engine [Re: atikovi] #5228741 10/02/19 06:55 PM
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PandaBear Offline
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Originally Posted by atikovi
The thing I find interesting in that page is the 8:1 compression is for more power while 14:1 is for efficiency. Pretty much the opposite of established hot rodding practise of higher compression = more power.


You do not want to handle any turbo boost at 14:1, and you do not want to run 8:1 if you are just cruising the highway at 70mph.

Last edited by PandaBear; 10/02/19 06:55 PM.

"You keep asking questions PandaBear and you'll end up a vegetarian like my wife" - Camu Mahubah
Re: infinity variable compression engine [Re: edwardh1] #5229035 10/03/19 04:02 AM
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Mazda had a much smarter plan by cooling the EGR gasses significantly, allowing them to not have to dump fuel to cool the cylinders. It worked very well, too in the real world, as most of us CX5 turbo owners see far better than EPA. I'm sitting on 26.4mpg lifetime, while the vehicle is only rated at 27 hwy. Just like Mazda said, it kills its EPA ratings. Most review magazines saw the same thing, with it getting 30+ doing 75 on the freeway.

Last edited by Ws6; 10/03/19 04:02 AM.
Re: infinity variable compression engine [Re: edwardh1] #5229043 10/03/19 04:44 AM
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Xeno Offline
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Early tech is always risky, but as they refine it over there years, the potential benefits are huge. Nissan engines have generally been pretty solid (increase in quality across the board since 2007+), the same can't be said for their CVTs, sadly.

Last edited by Xeno; 10/03/19 04:46 AM.

2006 Sentra SE-R Spec V 100k miles
Redline MT-85 | M1 EP 10w-30 | Wix | AEM Dryflow Drop-in
2009 Altima Sedan 2.5s MT 69k miles
Redline MT-85 | M1 EP 5w-30 | Wix XP | AEM Dryflow Drop-in
Re: infinity variable compression engine [Re: edwardh1] #5233339 10/07/19 07:53 PM
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Infinity is in the toilet with sales. They had a 40% drop last month and pulled out of Europe.

Not sure why they bothered with this engine as it’s not interesting to the average luxury buyer.

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