View Single Post
Old 04-10-2008, 08:17 PM   #4 (permalink)
LostCause's Avatar
Join Date: Feb 2008
Location: California
Posts: 504

Thunderbird - '96 Ford Thunderbird
90 day: 27.75 mpg (US)
Thanks: 0
Thanked 7 Times in 7 Posts
Great articles SVOboy and tasdrouille.

What I don't understand is how the heightened compression ration will be used. If knock isn't going to be eliminated by direct injection or some other technique, is there something I'm missing? I suppose an engine may not knock under low load (cruising) and only under acceleration...

I also wonder why variable compression can't be achieved with variable valve timing. Toyota's "Atkinson" cycle engine uses late valve closure to reduce the compression ration, so why not apply variable valve timing to choose high, low, or gradations in between as technology becomes more advanced. Seems simpler than linkages, moveable heads, variable height pistons, etc.

- LostCause
  Reply With Quote