Recent Topics
2004 Cummins 480 CE Marine Engines
by jmichels - 10/18/19 06:29 AM
Deleted vs Non-Deleted UOA
by oakaro68 - 10/18/19 05:30 AM
3.2 V6 Cayenne oil help
by Abax25 - 10/18/19 04:16 AM
Can cops sit in the median with no lights on at night time?
by motor_oil_madman - 10/18/19 12:24 AM
2012-2014 Lexus GS350 AWD Reliability?
by GZRider - 10/17/19 10:28 PM
Switch to High Mileage Oil or No?
by Blake1107 - 10/17/19 10:21 PM
Found this funny
by taztheman - 10/17/19 10:04 PM
How much gas to start a 3L or larger engine?
by paulri - 10/17/19 09:54 PM
Syneresis, learned a new word today!
by Cujet - 10/17/19 09:28 PM
What is more important in an oil?
by Rglossip - 10/17/19 08:03 PM
Chevy 2.4 Oil Burner Oil/Filter Change?
by GaryPoe - 10/17/19 07:57 PM
2016 F150 2.7 UOA 4k
by tomcruise - 10/17/19 07:13 PM
Mobil1 5W-30, 8,200mi, 2017 Expl 2.3EBBB
by Whimsey - 10/17/19 07:01 PM
How To Avoid Deer?
by Passport1 - 10/17/19 06:41 PM
Mazda6 P0401 code
by miden851 - 10/17/19 06:15 PM
2004 Crown Vic shock/ struts recommendation
by umungus1122 - 10/17/19 06:12 PM
Undercarriage pics of my 2003 E46 330Ci ZSP
by SLO_Town - 10/17/19 06:11 PM
Porter Cable air compressor not shutting off
by JLawrence08648 - 10/17/19 06:06 PM
Newest Members
JCunningham, TomStackhouse, Drinksprite, jmichels, Collins92
69594 Registered Users
Who's Online Now
72 registered members (Bailes1992, AurionX2, aquariuscsm, 1960Elco, Bettez88, atikovi, 4 invisible), 1,235 guests, and 21 spiders.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums67
Topics296,126
Posts5,091,653
Members69,594
Most Online3,532
Jul 30th, 2019
Donate to BITOG
Print Thread
Hop To
Page 1 of 2 1 2
infinity variable compression engine #5227934 10/01/19 08:33 PM
Joined: Jan 2003
Posts: 3,300
E
edwardh1 Offline OP
OP Offline
E
Joined: Jan 2003
Posts: 3,300
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
Joined: Apr 2010
Posts: 2,609
A
atikovi Online Content
Online Content
A
Joined: Apr 2010
Posts: 2,609
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
Joined: Jul 2014
Posts: 1,245
N
Number_35 Online Content
Online Content
N
Joined: Jul 2014
Posts: 1,245
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
Joined: Dec 2017
Posts: 2,777
J
JLTD Offline
Offline
J
Joined: Dec 2017
Posts: 2,777
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


I use the overseas manual to choose my viscosity.

Using AMSOIL

Hers: 2008 Jeep Liberty 154k, SS 5w30/Amsoil

His: 2015 4Runner 60k, SS 5w20/Amsoil

Re: infinity variable compression engine [Re: edwardh1] #5228019 10/01/19 11:51 PM
Joined: Aug 2018
Posts: 287
G
GZRider Offline
Offline
G
Joined: Aug 2018
Posts: 287
"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
Joined: Mar 2008
Posts: 1,697
W
Ws6 Offline
Offline
W
Joined: Mar 2008
Posts: 1,697
Seems like a fail compared to other competitors.


2019 CX5 Grand Touring Reserve
Re: infinity variable compression engine [Re: edwardh1] #5228147 10/02/19 07:24 AM
Joined: Feb 2003
Posts: 8,890
C
Cujet Online Content
Online Content
C
Joined: Feb 2003
Posts: 8,890
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
Joined: Jun 2002
Posts: 13,316
K
Kestas Online Content
Global Moderator
Online Content
Global Moderator
K
Joined: Jun 2002
Posts: 13,316
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
Joined: Aug 2018
Posts: 287
G
GZRider Offline
Offline
G
Joined: Aug 2018
Posts: 287
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
Joined: Apr 2010
Posts: 2,609
A
atikovi Online Content
Online Content
A
Joined: Apr 2010
Posts: 2,609
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
Joined: Aug 2002
Posts: 15,407
P
PandaBear Offline
Offline
P
Joined: Aug 2002
Posts: 15,407
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
Joined: Aug 2002
Posts: 15,407
P
PandaBear Offline
Offline
P
Joined: Aug 2002
Posts: 15,407
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
Joined: Mar 2008
Posts: 1,697
W
Ws6 Offline
Offline
W
Joined: Mar 2008
Posts: 1,697
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.

2019 CX5 Grand Touring Reserve
Re: infinity variable compression engine [Re: edwardh1] #5229043 10/03/19 04:44 AM
Joined: Nov 2008
Posts: 199
X
Xeno Offline
Offline
X
Joined: Nov 2008
Posts: 199
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
Joined: Jul 2015
Posts: 5,270
M
madRiver Offline
Offline
M
Joined: Jul 2015
Posts: 5,270
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.

Page 1 of 2 1 2
Previous Thread
Index
Next Thread

BOB IS THE OIL GUY® Powered by UBB.threads™