variable cam profile/timing (was: Twin injector system?)

[goflo at pacbell.net]

> > I always thought it would be way cool to have the valves activated
> > hydraulically, controlled by solenoids or something. But I have no
> > real idea how to do this. I would think that a completely flexible
> > "cam" profile would be a real big advantage, and since I haven't
> > seen it anywhere I assume it must be a very difficult thing to do.
> 
> Allow me to point you to Racecar Enginnering, a UK publication. A recent
> issue featured electronically (solenoid activated) valve technology.
> Apparently at the experimental stage, it does solve a lot of problems
> associated with conventional valve technology. There was a working model
> featured but, as with prototypes, it wasn't pretty.

Another hardy perennial - This idea has been around a long time.
Attended a TRW seminar 13 years ago where the hot topic was ceramic
valves - One engineer made the statement that if they could get the
cost down to >$10 US apiece (in quantity)they'd have the whole market 
because their light weight made solenoid-operated computer controlled
valve train feasible. Maybe so ...
If you start pencilling this out it's not hard to convince yourself
that you could make the torque curve look like a steam engine with 
such a scheme. And maybe double the mpg. A little reflection on valve
dynamics and the characteristics of solenoids throw a lot of cold
water at you though.
Not that it can't be done. It has been done.

Jack