EFI for Propane

[Clarence L.Snyder]

> The pump would pressurize the propane to arount 330 PSI.  This would be
> fed into the input side of the injecter.  The output side would be
> connected to something similar to a diesel injecter, which is a valve
> that opens at a specific pressure.  If it is set to 300 PSI, the injecter
> will "see" a pressure differential of 30 PSI, and will be fed with
> relatively warm propane.

You don't need a pump if you take propane off the bottom of the tank -
called liquid withdrawal. This is standard for automotive propane
systems. It IS liquid when it hits the "evaporator" - you know, that
water heated thingamagig used on "carbed" propane units. The pressure
varies with tank(vapour) temperature - not with fuel level, so it would
not be hard to calibrate an EFI to use liquid propane. The problem I see
is getting an injector to do the deed. Mabee try the electronic
controlled injectors from something like a Ford Powerstroke or
electronically managed Cummins or Mack. Not sure how they work, or if
they require lubrication. Size the injector to flow 15% more fuel than
you would use for gasoline to start because energy density of propane is
about that much lower (If I remember correctly - my propane days go back
a little while)
The big problem, at least here in Ontario, would be getting the bugger
certified so you would be allowed to re-fuel it. Lots of little things
you would not think of, I'm sure.