Electronic valve control

[Clare Snyder]

BUTLER, Tom wrote:
> 
> > -----Original Message-----
> > From: Clare Snyder [SMTP:snyder at huron.net]
> > Sent: Monday, February 09, 1998 9:14 AM
> > To:   diy_efi at efi332.eng.ohio-state.edu
> > Subject:      Re: Electronic valve control
> >
> > dzorde wrote:
> > >
> > > I think you would eventually break the valve from the stem due to
> > the sheer
> > > hammering of the valve against the seat.
> > >
> > > Dan     dzorde at geocities.com
> > >
> > > >Actually there have been a few engines built and run with solenoid
> > controlled
> > > >valves........however they are VERY noisy, this is because as the
> > solenoid
> > > >begins to close the valve it accelerates considerably resulting in
> > slamming
> > > >the valve in its' seat whereas a cam actutated valve will be placed
> > on its'
> > > >seat with zero velocity. I have heard that the solenoid engines
> > sound alot
> > > >like diesels....
> > > >
> > > >Scott Shotton wrote:
> > > >
> > > >> delsol wrote:
> > > >> >
> > > >> > Has anyone had any experience with electronic control of
> > engine valves?
> > > >> >
> > > >> > Ideally no cam would be involved. Any ideas or info, anyone?
> > > >> >
> > > >> > Daniel
> > > >>
> > > >> This idea has crossed my mind before.  Computer controled valves
> > would
> > > >> be an invaluable tool.  Infinate duration and timing
> > posibilities.
> > > >> However, as far as I know, solenoid technology is not good enough
> > for
> > > >> that particular application.  I wish it were!
> > > >>
> > > >> Scott
> > > >
> > > >
> > > >
> > > >
> > What about hydraulic or pneumatic control, with computer controlled
> > solenoid control of the fluid system?
> > --
> >                                _/\_
> >                        --|-----([])-----|--
> >                          S    0/  \0    B
> >          Alls well that ends well!! www.snyder.on.ca is back
> >                   E-Mail service is back to normal
> >                   To avoid bouncing E-Mail messages
> >                     Reply to Clare at snyder.on.ca
> >                                 OR
> > Remove the R from clsnyder in my E-Mail Address to reply. Stop the
> > spammers!!!
> > It's hard to soar like an eagle when your stuck with a bunch of
> > Turkeys!!!
> >
> >
>         The problem here is that you need the engine running in the
> first place in order to have hydrualic pressure or pneumatic pressure to
> actuate the valves.  You have a chicken and egg problem.  While it is
> possible to have some sort of reservoir to hold pressure, you still have
> to worry about pressure leak-down.  Even if your seals are perfect, what
> about a hard starting situation?  How much reserve capacity must you
> have?  Some arrangement might be made to pump up pressure in an engine
> non-start situation, but compexity is going way up.  Solenoid actuation
> seems to me to be the only viable avenue of pursuit.  I don't dislike
> cam shafts enough to want to cause myself that much brain damage
> however.
> 
>         Tom Butler  TEBUTLER at MCCAIN.CA
How about an electric oip pump  (or compressor) to provide starting
pressure?
-- 
                               _/\_
                       --|-----([])-----|--
                         S    0/  \0    B
         Alls well that ends well!! www.snyder.on.ca is back
                  E-Mail service is back to normal
                  To avoid bouncing E-Mail messages
                    Reply to Clare at snyder.on.ca
                                OR
Remove the R from clsnyder in my E-Mail Address to reply. Stop the
spammers!!!
It's hard to soar like an eagle when your stuck with a bunch of
Turkeys!!!