I was shopping for a used Q50 to replace my daily driver and a new QX50 was on the lot and caught my wife's eye. The salesman informed us about the engine. I haven't heard of such an animal yet, but it basically sounded like the rotating assembly moved up and down inside the block to change compression? Also, he mentioned the transmission uses the GPS to tell the transmission what grade to expect to avoid unnecessary upshifting and downshifting. Once again, this old man was in the WTF mode. The world is a changing. https://www.infinitiusa.com/crossov...VUj0MCh3YWQ38EAAYASAAEgJJ6vD_BwE&gclsrc=aw.ds BTW, purchased a used Q50 and really like it.
Variable valve timing has been around for awhile now. If you close the intake valve sooner, you boost dynamic compression. Is that what they are doing? 8:1 to 14:1, valve timing won't do that. Very interesting. Wonder why 8:1 is performance? and 14:1 is efficiency?
Nope, not variabel valve timing, that's from the 80's i think.. Toyota, Honda, BMW, Suzuki and so on used/uses it.. There's also "Sky Active" by Mazda
It's about time, I guess Infinity was willing to pay for the patent or bought the company who invented it.
That was my first thought on the dealership lot, but after having watched the video, I could see this thing being pretty reliable. I would like to see how they keep this thing lubed and what the fail safe is should the motor controlling the variable arm fail.
I went to Atlanta’s Pull A Part today and saw two BMW 7 series, a late model Cadillac STS and more Audis than I could count, none wrecked or rusty. They all were there (presumably) because some complicated part doomed them by failing and killing what little residual value they had. (On a previous trip I saw a VW Phaeton!) A great deal of modern technology makes cars require less maintenance and fuel but once they hit 10-15 years old they crap the bed so bad they’re gone. Used to be an old luxury or ‘special’ car might not have all its accessories functioning but it wasn’t hard to keep it running, not fear the reaper; maybe even see the value rise again. That’s not the future... Patrick
All this additional complexity makes me think we are nearing the end for internal combustion engine technology. Car manufacturers have to resort to all kinds of crazy schemes to achieve fuel mileage and emissions targets. For instance Volvo sells a hybrid engine that is not only electrically assisted, it also turbo charged AND supercharged. Having said that, the Japanese OEMs are usually pretty fanatical about quality so I would expect the Nissan engine to not have any baseline reliability issues. Not sure I would want to pay to have one rebuilt but it should work fine for the normal life of the car. I wonder if the oiling method is similar to whatever they had to do for old school Radial engines with master connecting rods? http://www.aviation-history.com/engines/radial.htm
It's really a pretty amazing design. Surprisingly simple... wonder why it hasn't been done before. The only downside I can see is the additional rotating mass it's adding to the crank. I think we're in the final golden age of internal combustion design. They are pulling all the stops to get the last bit of efficiency
Remember all the crazy, complicated and unreliable devices OEMs had to put on engines to meet emissions standards in the 1970s and 80s? I think we are at a similar point in the cycle. No reason why technology won't come give us a similar improvement as what we saw in the decades following the smog years.
I have to respectfully disagree with you. There is only so much that can be squeezed out of an internal combustion engine in its traditional form. The difference in technology then compared to now is massive, and it's all due to the coming of age of modern electronic engine control systems that are fast enough to close the loop (get feedback, analyze the result, and take corrective action) on devices like variable valve timing, this variable compression system, and fuel / spark control. Also, computer aided design and analysis, and manufacturing have brought about more precision in mechanical components. There would have to be a revolutionary discovery at this point to advance the state of the art beyond small incremental improvements. The 70's and 80's were really the dark ages compared to where things are now.
Sure, but isn't that the same people thought in the 70s and 80s, that they had reached a plateau in technology?
I'm sure, but don't you think they had much less of a grasp on things back then? To meet emissions in the 70's, they dropped compression through the floor, which killed efficiency. Totally the wrong move. All of the steps they took made efficiency worse. I think there is much more understanding now about the combustion process now. For example, look at some of the newer Mazda Skyactiv engines operating at super high compression ratios. Hey, you could be right, no doubt. But, I believe that we've got a much better understanding of the basics and are now just milking the remaining gains, which have diminishing returns. It will be interesting to see where they find the gains. The real stop to development will probably be when battery technology comes of age and everything goes electric.
