Electronic valve control

[steve ravet]

Shannen Durphey wrote:

>   I guess my earlier post never made it through.  One way to do this would
> be to control the lifter bleed down rate.  If the cam had a high lift/long
> duration lobe, then the bleed off could be held to a minimum during the
> earliest part of the lift, and then dumped before the valve is open too long
> to create early valve timing and lift.  As RPM increases, this could be
> reversed.  If the lifter were made such that it had a minimum mechanical
> lift then it would always open the valve no matter how much fluid pressure
> there was within the lifter body.  In current engines, this could give a
> rough form of valve control by using lifters with a fixed bleed down rate
> and controlling the supply pressure.  Crude, but still better than fixed
> lift and duration.
> 
> Shannen

That already exists, it's called a Rhoads lifter.  It collapses more at
low RPM, which gives your lumpy cam a better idle.

I know the electric valve topic has come up before and gotten some good
discussion, esp from the Ford guy (Ed Hernandez??)  Haven't seen him
post in a while, though.  One of the good ideas that came out of the
discussion was eliminating the starter:  Computer locates a couple of
pistons that are near the top of the power stroke.  Open the intake,
squirt in some fuel, close the intake, apply a spark, voila the engine
is started.

--steve

--
Steve Ravet
International Meta Systems
http://www.imes.com
steve at imes.com