Nissan-variable compression engine-NGC

[chuck peterson]

http://www.reuters.com/article/us-autos-japan-nissan-engine-idUSKCN10P0IK?il=0

[Phang]

a glorified Atkinson cycle engine? 

[not-fishing]

I'm waiting for camless engine. 

Dropping the cam and associated parts will really free up horsepower.



http://blog.caranddriver.com/koenigseggs-camshaft-less-engine-explained-watch-it-in-action-video/

[brlawson]

https://www.youtube.com/watch?v=DdM2VbbdtB4

[LowRyter]

http://www.reuters.com/article/us-autos-japan-nissan-engine-idUSKCN10P0IK?il=0

I wonder how it works?  Maybe closeted combustion sub-chambers?  Retractable head?

The article had no explanation of the mechanics and tech.

[pikipiki]

I suspect it's just a variable geometry turbo or it could be inlet valves that can be controlled to stay open through the initial part of the compression cycle Nisan already do that with Dig-T and Dig-S engines.

Fiat have developed hydrolic valves to replace inlet valve cams.

Saab prototype had true varialble compression 10/15 years ago.

[Penderic]

Here is the first one ......



 

[Testarossa]

For a number of years MAN B&W and Warstsila have been building marine diesels with electrohydraulic valves and no camshafts. Like the Freevalve design, they use a rail to control the variable valves along with fuel to the injectors. Being able to open and close the valves more than once per rev enables a two-stroke cycle. These are huge main-drive engines for container ships.

[ITSec]

I'm waiting for camless engine. 

Dropping the cam and associated parts will really free up horsepower.



http://blog.caranddriver.com/koenigseggs-camshaft-less-engine-explained-watch-it-in-action-video/

Formula1 has been camless for a while - and has used some fairly exotic combinations of long-shaft turbos and hybrid power-scavenging that could actually be applied to mass production products.

The new Nissan design, effectively changing the length of the connecting rods, is a very distinct design; till now, compression changes have largely been done through variable valve timing. VVT can be done with both cammed and camless designs, and may be less mechanically complex than the Nissan approach - though with less range of compression variability.