Re: LPG in cars

["Jim Blair" <carnuck@xxxxxxxxxxx>]

A: Auto fuel injection systems with LPG use liquid that is pumped to the 
front. The older carb mixers on dual fuel use vapor from the tank (which is 
why the tanks ice up, even on sunny days on long hill climbs), and I had a 
BBQ tank for backup on long trips with a manual switchover valve. I could 
always tell I was near running out about 50 miles before it did because the 
car's power would nosedive as it reached the end. One time I ran out of even 
my backup tank, but I let it sit a couple hours till it warmed up outside 
and got just enough vapor to slow cruise the last mile to the station! (I 
had a 600 mile range with my slant 6 and somehow I forgot to write the 
mileage down from the previous fillup)


From: Tom Jennings <tomj@xxxxxxx>
To: mail@xxxxxxxxxxxx
Subject: Re: LPG in cars
Message-ID: <20050509002108.H10273@localhost>

On Sun, 8 May 2005 mail@xxxxxxxxxxxx wrote:

> Saw a post on using LPG in cars, and there are many
> advantages to it. The main dis advantage is where to
> fill up. Can't you just fill up at home? There is a
> company that has produced a home filling station that
> basically just lowers the pressure coming out of the
> home line. Couldn't you just set up a "T" and use that
> to hook up your filling station.....Russ

Nahh, it's gotta be pumped into the car tank. The reason is that
when you connect two tanks together, fuel will flow from the
fuller one to the emptier one only until the pressure equalizes.

Plus home (propane, not natural gas) tanks dispense gas, and auto
systems dispense liquid. For BBQs and stoves gas it picked off the
top of the tank, for LP car systems liquid is taken off the bottom
of the tank.

Think of it as a sealed tank filled with boiling liquid; off the
top is steam (gas) at the bottom is liquid. In fact this is almost
exactly what's going on with LP -- it boils to "steam" (LP gas) at
-22F.


(You can make a "gas can" for LP cars with a 5-gallon BBQ can with
the internal safety valve removed; with a special double-ended
hose (1-3/4" acme to POL) you connect a TOTALLY FULL 5-gal can to
a TOTALLY EMPTY car tank, tip the 5-gal upside down, then open the
valve.  About 4 of the 4.5 gallons the can will fill the big empty
tank, at which time the pressures equalize.

(New BBQ cans have a safety valve that prevents overfilling and
also prevents dispensing liquid when turned upside down. It's a

good idea, except for use as a gas can :-)