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)
Wow, never heard of vapor-fed motors! That sounds very kludgey. My car is dead-ordinary: liquid to the engine compartment, through the filter/shutoff, to the converter, which is a coolant-heated two-stage converter that outputs -0.5" water column LP gas, via 1" hose to the carb.
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 :-)