Date: Fri, 29 Apr 2016 09:40:30 -0700
Reply-To: David McNeely <davmcneely40@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David McNeely <davmcneely40@GMAIL.COM>
Subject: Re: Friday: New VW Engine--it's Miller (cycle) time
In-Reply-To: <0560F7DC-96B7-43B8-9748-990C2A1C2806@shaw.ca>
Content-Type: text/plain; charset=UTF-8
The Mazda engine could never meet emissions standards, and was dropped,
iirc. True of their earlier rotary engine as well.
On Fri, Apr 29, 2016 at 9:01 AM, Alistair Bel <albell@shaw.ca> wrote:
> VW , where our heads are firmly buried in the sand.
>
>
> http://www.theguardian.com/environment/2016/apr/28/vw-and-shell-try-to-block-eu-push-for-cleaner-cars
>
>
> And didn't Mazda sell a Miller cycle engine in a couple of models way back
> in the nineties?
>
> Alistair
>
>
>
> > On Apr 29, 2016, at 8:39 AM, Jim Felder <jim.felder@GMAIL.COM> wrote:
> >
> > From Gizmag.com today:
> >
> > Manufacturers are leaving no stone unturned in the quest to improve the
> > efficiency of their internal combustion engines. Just this week, we've
> seen
> > a fastidiously engineered diesel engine
> > <http://www.gizmag.com/ford-ecoblue-diesel-engine/43016/> from Ford
> > and a camless
> > engine <http://www.gizmag.com/qoros-qamfree-camless-engine/43045/> from
> > Qoros. Now Volkswagen, no stranger to doing whatever it takes to lower
> > consumption (figures), has joined the party by releasing a 1.5-liter
> Miller
> > Cycle <
> http://www.gizmag.com/audi-high-efficiency-two-liter-engine/37428/>
> > engine
> > tasked with improving fuel consumption and increasing low-down torque.
> >
> > Volkswagen's engineers say there are a number of improvements that come
> > courtesy of the improved thermodynamic efficiency associated with Miller
> > Cycle engines. An increase in the geometric compression ratio has,
> > according to VW, allowed for improved efficiency in the load range most
> > customers will actually use, while the final compression temperature has
> > been lowered through early closing of the intake valve and the expansion
> > cooling that brings.
> >
> > Thanks to these improvements, VW claims its new engine offers up peak
> > torque from just 1,300 rpm, while also improving fuel economy by 1 l/100
> km
> > (235 US MPG) compared to the current 1.5-liter TSI engine.
> >
> > Working tandem with these big changes to the combustion cycle are a
> number
> > of small changes that, when combined, contribute to the longevity and
> > efficiency of the engine. On the 110 kW (148 hp) version of the engine,
> the
> > cylinder liners are coated with an atmospheric plasma spray to cut down
> on
> > friction, improve heat dissipation and improve corrosion resistance.
> >
> > The engine's cooling system has also come under the microscope, and now
> > will make sure the water in the crankcase and engine remains stationary
> > while the car is warming up. As well as cutting the amount of time spent
> > without the engine operating at ideal temperature, VW says the system
> helps
> > warm the cabin more quickly on cold mornings.
> >
> > Although it's usually used on high end, big displacement engines, VW has
> > even fitted cylinder deactivation to the new engine, allowing it to run
> as
> > a two-cylinder under light loads.
> >
> > An increasing injection pressure 350 bar has improved the mixture
> formation
> > in the engine, which should also lead to lower particulate emissions.
> >
> > Interestingly, the release makes it very clear the efficiency and
> emissions
> > improvements are unlikely to show up under test cycle conditions, but
> > argues that they're likely to have a "distinct impact on the customer's
> > everyday driving."
> >
> > The new four-cylinder engine will find its way into showrooms later this
> > year in 96 kW (129 hp) and 110 kW (148 hp) guises. It's currently on show
> > at the Vienna Motor Symposium.
>
|