VCR (Variable Compression Ratio Engine)

[Bishop]

http://www.youtube.com/watch?v=DdM2Vbbd ... plpp_video

very interesting idea and i will be curious to see whether it goes in to use.

[sc90]

thats pretty cool :O

[xABSOLUTIONx]

is it just me or the engine seems too complicated in it's operation to be used on a daily basis?

[Bishop]

its actually not that complicated mechanically, its the electronics or whatever system they use to control it that is gonna be a little troublesome.

[quantexrox]

I believe saab thought this up a while back (but was shelved when they were bought by GM,) by hinging the block and moving the top half/head to one side. Moving it to the side would lower the compression ratio as the distance between the head and crankshaft would increase as it would tilt, lowering the compression ratio. You couldn't make the drastic changes like this video promises, but it was mostly for emissions and fuel economy.

Also, many old diesel engines had a plenum mounted above the head that would allow the compression ratio to decrease from 14-15:1 to around 6:1, with a simple gas carb connected to the air intake and sparkplugs in the combustion chambers. This meant you could start the engine on gas (a much more reliable and easy way in the days before glow plugs were semi-reliable and electricity wasn't always available for block heaters,) with the plenum open and connected to the combustion chambers, then switch to diesel once the engine got warm. Not exactly along the same lines as the video, but interesting none the less