Generator Fuel Line

[Steve]

If I wanted my generator to draw fuel off the buses gas tank instead of it's own. Where would I want to tie into the line at? Will I need an electric fuel pump?

[lapeer20m]

if the bus fuel tank is higher than the generator's carberator, you do not need a fuel pump. I love the idea of using the bus' tank for the geni....unfortunately most of us have diesel and don't have that luxury. Small diesel generators are not common, cheap, or light.



If your geni's carberator is higher than the fuel tank, then you need a fuel pump. An electric one can be purchased for about 50 bucks from an autoparts store. or you could scam one from a junk yard. The important thing is to make certian that your geni runs out of fuel before the bus does. Ideally you want the geni to run out of fuel when the fuel tank is down to a quarter tank.



My bus has a drain plug on the bottom of the fuel tank, if your's does too, then you're in luck. You can pull the plug, drain the fuel, and reinstall a "T" with a cap on one end, and a fitting for your fuel line on the other side of the "T" A quarter turn shutoff valve should also be installed.



I don't know if i can explain the immage in my head clearly enough. But to make the geni so that it can't completely drain your fuel tank, all you need is a tube that's 1/4 as tall as your tank is deep. Before getting anywhere near the gasoline, you want to braize/solder the tube to the inside of the pipe that threads into the bottom of the tank, making certian not to damage the threads. this pipe is then attached to the "T" that goes to the geni.



Hope this helps. ......I almost wish i had a gasoline motor in my bus........on second thought NO I DON'T! LOL

[Vern1]

Greetings,

I agree with most of what you said.

The only difference for my particular situation is I would tap a little lower into the fuel tank.

As an example:

I have a 75 gallon tank and a gas genset with an electric fuel pump on the genset.

If I set my fuel pickup so the genset stopped running when it still had 18 - 20 gallons of fuel, even at 5 MPG, I would have to drive that last 100 + miles without AC - it gets hot here in Texas!

If you are doing a lot of boondocking, I could see holding the pickup off the bottom of the tank, since you don't want to run the tank dry 50 to 100 miles from the nearest gas station.



You would ALWAYS have to have 1/4 tank just so the genset would run.

So, it depends on your situation and how you use the bus.



Just my spin......

Cheers,

Joe Petty

[lapeer20m]

good point !



I know there are times when i can't afford to keep my bus above one-quarter of a tank full !

[Les Lampman]

Another consideration when contemplating gravity feed for a genset is where the genset is in realtionship to the tank in varying situations. The genset on our Class C worked fine with gravity feed until I climbed a steep grade; then the fuel tank (located at the rear of the rig) was lower than the genset (located near the front) and the genset stopped. An in-line electric fuel pump solved that problem .

[Steve]

And there is no problem with the pump being to powerful? I know I had a little 2 cycle that would just dump gas out the exhaust while I had an electric fuel pump attached.

[Vern1]

Greetings,

On fuel pumps.

For a lot of small engines, snow-mobiles come to mind because I have used those engines on ultralight aircraft, different sizes of float valves are available.

For instance if you used a pump, you used the smaller size because it was forced and the smaller orfice would put less pressure on the float.

When you were gravity feed, you used the larger size because the float didn't have to push against so much pressure.



There are adjustable electric fuel pumps out there and you can also get them in different fixed output pressures.

Regular old carburator has a big old fuel bowl, easy to keep up with the intake of the engine, but needs a LP pump.

Fuel injection doesn't have the "tank" of fuel right at the injectors, so the pressure needs to be higher to keep up when you nail the throttle.



There are also fuel pressure regulators that are stand alone units. Most of the ones I have seen in racing environments are adjustable from 0 to ???.

If you are using a briggs/stratton, small honda, techompse(sp??), etc. 2 to 5 PSI output should work for you if they were initially gravity feed.



The diaphram pumper type carburators don't like much pressure and will pulse, surge and flood when force fed with a pump. Typical users of this carb are chain saws, weedeaters, very small two-stroke generators, etc.



Hope this helps!