Reply to: Re: Variable Cam Timing, etc...

[RABBITT_Andrew at mv8.orbeng.com.au]

Lotus have a Electronic-over-Hydraulic valve actuation system which I 
think they use for cam profile development.  I think it was a spin off 
of their active suspension technology (really!) and according to 
sources, they could 'square-wave' the valve timing to more than 4000 
rpm!  There might be some SAE papers on the project.  Power 
consumption and complexity were big hurdles, hence its use only in the 
test cell.

Andrew Rabbitt
oecar1 at orbeng.com.au

From: (Timothy Coste) tlcoste at mtu.edu:smtp
Date: ## 05/07/96 17:31 ##
This isn't anything real helpful on how to do this, but I could of
sworn I remember researching several articles that were at least
from the mid to early eighties, if not earlier, on using solenoid
operated valves...at least in a research project.  I know power
draw was a major concern but I remember that durability was at
least as big a concern as power draw or anything else.  Has
something changed in the last decade, or is it not as big an issue
as I remember it being?  I do like (and could swear I'd heard of
it somewhere before) the half-open idea.  More solenoids but each
is a lot less worked (more durable and less power) than one big
solenoid.  Novel approach.  Guess I'll have to try and look up
the old articles.  I think it was for a senior design project
now that I'm thinking about it more.

   Tim Coste
   tlcoste at mtu.edu