On Sun, 4 Jan 2004 15:49:54 -0600, "Biker_Bry"
wrote:


"QrizB" wrote in message
...
On Sun, 4 Jan 2004 11:41:43 -0600, "Biker_Bry"
wrote:

The difficulties to overcome LPEFI are as follows...
1. Propane cannot hold a liquid state at underhood temps (207deg F)
2. Liquid must stay at the injector at all times while running (fuel
pump
nessisary)
3. Vehicle must complete a purge cycle before starting similar to a
diesel
waiting on glow plugs.
(to rid the fuel lines of vapor).

I've been wondering if any of this is really an issue. The aim, as I
see it, is to have gas injection to the cylinder rather than to the
inlet tract. Does it actually matter whether you're injecting a liquid
or a gas?


If vapor is coming out the injector, you will only supply the cylinder
1/270th of the required fuel.

Not true. Think about the phase diagram. At temperatures above the
triple point of LPG, the vapour can have the same density as the
liquid.

4. Fuel Pump must be inside the tank, so how do you pass wires through a
fuel tank and have it safe?

And call me thick, but why does the fuel pump have to be inside the
tank? ISTM the pump could be anywhere upstream of the injectors, as
works perfectly well with diesel.

If you put the pump into another container upstream, it still must meet all
the vessel safty critera that a propane tank must meet.

Why does your pump need to be in a "container"? People have been
designing high-pressure liquid / gas pumps for generations. I'll
accept that any pump will need to be suitable and approved for pumping
lpg.

Even with this, there is a problem with cavitation when the vehicle is
situated uphill, or down hill in relation to the pump vessel intake.

Not if you get your pump design right.

--
QrizB

I sound like I know what I'm talking about, but don't
be fooled.