Switching between fuel tanks while driving

[The_Handier_Man1]

From: racenu  (Original Message)
Sent: 10/8/2003 11:31 PM

WE HAVE JUST PURCHASED A 1977 WINNEBAGO CHIEFTAIN
AND WE ARE VERY NEW TO THE MOTORHOME EXPERIENCE...
WE ARE WONDERING CAN WE SWITCH FROM TANK TO TANK WHILE DRDIVING?



From: Harold
Sent: 10/9/2003 3:02 AM

THE ANSWER IS YES. I DO IT ALL THE TIME ON LONG TRIPS. I TRY AND KEEP THE MAIN TANK ABOVE 1/2 SO I CAN RUN THE GENERATOR WITHOUT RUNNING OUT OF GAS.
                                                               HAL



From: denison
Sent: 10/9/2003 6:36 AM

We also switch while driving. I have chosen to run each tank dry on occasion, just to find out how much fuel it took to fill a tank that had been emptied. I have a fuel pressure guage that lets me do this without having the engine die on me. Ive also learned how many miles I can run on each tank after the needle is on Emmpty!
One reservation though: If you run a tank empty, and you switch to the other tank - you really hope the tank selector valve/solenoid will work. I plan to install a new tank selector valve/solenoid, just because the original is 31 years old. Also I will ensure the rubber fuel hoses from each tank have enough slack to reach the other port, if the valve fails someday. denison 



From: jbrt1989
Sent: 10/9/2003 11:10 AM

Heck of  an idea there denison.

  Having a hose at each tank to reach the other tank could be a lifesaver on the road. 

I was driving an old Ford pickup several years ago across country that had dual tanks.  Halfway into the trip,  I couldn't get it to switch tanks as I ran down the primary tank,  leaving me stranded out of gas in Texas, miles away from the nearest town,  with one full tank of gas.  My last ditch was to literally grab a hose  I fortunately had, from the back, cut off a chunk and siphon about 10 gallons from one tank to the other via a one gallon water jug and a funnel, all sitting on the side of the interstate in the middle of a Texas summer spewing some choice words with mouthfulls of gas, that to this day needs to remain just between me and that truck!

Jeff



From: photoman
Sent: 10/9/2003 1:42 PM

Denison...I always read your posts, no matter what the topic, as I always seem to learn something. I also switch tanks while driving my 72 C20. My aux tank gauge hasn't worked for several years so I always run it empty first before switching to the main tank (whose gauge still works). I jot down my mileage when I fill up & I know pretty close to how many miles I can go before the tank runs dry, so I'm ready with the finger to hit the switch when she starts to sputter.

I never risk running the tank dry when I'm driving thru the big city during rush hour. I switch to the main tank until I'm back on the hiway and then switch back to the other tank where I can pull off to the side of the road if I don't get her switched back quick enuf and she'd happen to die on me.

It never occured to me that the switch or the solenoid might not work. Good idea to make sure the hoses are long enuf to hook up to either port. You are so logical! I'm interested in your fuel pressure gauge. What's the cost? Hard to install? How does it work? Thanks. Photoman



From: denison
Sent: 10/10/2003 2:24 PM

photoman: If I was really logical I would have thought of making the hoses longer when I first replaced them in 1991, instead of just thinking of it this year.
Anyway --
My fuel pressure gauge has 3 components. The gauge which reads to 15 psi, An isolator, and the Interconnecting line. The isolator is a sturdy rubber diaphragm in an aluminum housing about 3 inches dia., with tube fittings to the chambers on each side of that diaphragm. One side connects to a Tee fitting I put into the fuel line between the fuel pump and the carburetor. Fuel presses on that side of the diaphragm. The other side runs to the gauge I mounted on the dashboard, and that line is filled with some inert liquid that wont freeze or burn, such as antifreeze - to transmit the displacement that the diaphragm sees from the fuel pressure, right to the gauge. Thus if the gauge or the interconnecting line begin to leak, you wont have any gasoline squirting into the coach, for the fumes to ignite when you create a spark by turning off the ignition, putting on the brakes, etc. The gasoline gets no further than the diaphragm. All of the auto racing organizations require isolators if fuel gauges are going to be mounted inside the vehicle. I got the gauge on ebay, cost about $30, later got an autometer isolator on ebay, cost about $75. I used 3/16th rubber fuel line type hose for the interconnecting line, filled with prestone. It took a while to get the line filled and the air bubbles out. This wasn’t supercritical or safety related, just makes the gauge more accurate and responsive. Now I can see the effects of the fuel filter clogging - the gauge will begin dropping on upgrades and gets more obvious as clogging progresses, even though the engine is running fine. Vapor lock also shows up before it happens, and if you are running on a nearly empty tank, the pressure will falter before the engine loses power, in time to switch tanks if your are paying attention. denison



From: photoman
Sent: 10/11/2003 9:51 AM

Thanks Denison for the info on your fuel pressure gauge. I've put it into my
winnebago file for a future project. Photoman