camless engine

[Ade + Lamb Chop]

At 10:30 31/01/00 -0700, Greg Hermann wrote:
>Long ago, had the fun of talking to a guy who had worked for Thompson Valve
>(now the "T" in TRW) about the hydraulic pressures that are encountered in
>hydraulic (self-adjusting) lifters. These are not only the sort of
>pressures you would be dealing with, but trying to switch on and off and
>start and stop the flow--consider the inertia in the fluid itself, as well
>as the weight of the valve. They are easily comparable the the higher range
>of diesel fuel injection pressures--2000  BARs!! (About 30,000 psi).
>
>Not saying it is not possible, just not too likely any time soon.
>
>Variable valve LIFT is not to important. Variable valve timing and duration
>has a LOT of potential. As is already being done, the most likely
>practical way of achieving it is with hydraulic/mechanical adjustment of
>the cam timing, and possibly next with multiple cam lobes per valve.
>Variable lift can be achieved on a practical basis with variable rocker
>geometry--and this is already being done, although not on a mass production
>basis.

How does Rovers VVC and Hondas Vtec stuff do it?

Ade

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