Author Topic: Deluxe fuel system (and how to know exactly how much fuel is in your tank!)  (Read 54 times)


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Want to easily determine the amount of fuel in your tank?
Weigh it!  (See photos, below). 

This method has three big advantages:
(1) it does not requier installing a gauge in the tank;
(2) the shape of the tank does not matter;
(3) it always gives temperature-corrected gallons.

The diesel fuel storage and gauging system describe here isn't
application-specific, but happens to be on a SR-1 Kohler genrator.   
I'm guess it may interest other generator users, since having the
lights go out unexpectedly is a pain.

Most of the parts (fuel line, fuel filter, etc.) are large enough to accomodate
the fuel flow requiementsof any Lister engine, but you have a larger engine,
you might need a larger  fuel tank, depending on your particular situation.


fuel_volume = (measured_weight - tare_weight) / K


fuel_volume is the amount of fuel left in the tank
measured_weight is the reading on your scale
tare_weight is the  weight of the tank when the engine
    runs out of fuel and starts sucking air.
K is a constant that depends on the units of measure.

USA example:

standard_gals = (measured_lbs - tare_weight) / 7.1

Diesel #2 fuel weighs 7.1089 lbs per standard US gallon.
("Standard gallon" means volume measured at 59.0 degrees F.
As diesel fuel warms up, it expands.)

Metric example:

standard_liters = (measured_kg - tare_kg) / 0.8598

because Diesel #2 fuel weighs 0.8598 kg per standard liter.


1 crane scale   
ModernStep digital crane scale, 300kg/600 lbs (made in China). 
Not great, but adequate.   Runs on three AAA batteries.

1 scale cover   
Zip-lock storage bag (to make scale more weather resistant)

1 tank             
15-gal stainless steel barrel drum, closed top

1 filler, cap and vent          
Assembled from galvinized pipe parts. Internal vent  and screen
added to filler.   External vent U-tube added to pipe cap.

1 tank lifting bracket   
fabricated (parts used to be the towing hitch for a '58 Porche
Speedster back in the day)

1 bung adapter   f
For fuel dip tube and fuel return line. NPT thread.

15 ft fuel line          
3/8" nylon air break line (meets DOT requirements)
with compression fittings

1 primer bulb   
Attwood universal 3/8" (WalMart)

1 course fuel filter   
Dutten-Lainson "Goldenrod" 496 with 496-5 water-block element.
Also removes paricles down to 10 microns.
Modified to add air bleeder valves on inlet and outlet. sides.

1 fuel lift pump   (not shown)
Carter P4070 universal in-line 12 VDC rotary fuel pump.
Sliding vane type.

1 fine fuel filter (not shown)
Kohler/Lister original part  on engine


The arm the crane scale is anchored to is an extension that fits into the
square stock inside the generator shark.  (The square stock has a sliding
anchor for the chain hoist used to lift the generator when necessary.)

After having a lot of problems with steel barrels rusting out, I went to
a stainless steel tank.   Copper fuel lines were causing black sediment,
so I went to nylon air break line instead.
I did not purchase a larger tank in order to insure that fuel would not
be stored for long periods (because of the problem of microbes growing
in diesel fuel).

I wish the tank had a drain to remove water, but adding one is not worth the
risk of creating a leak.  So I siphon the tank bottom about once a year.

I chose the Goldenrod filter because I can buy replacement elements locally,
and because I wanted a filter with a transparent bowl (with a drain).
It's designed for dispenser use and so is massive overkill for an engine.
Also, a filter that comes with bleeder vales would be better. 

The Lister built-in lift pump died years ago; then a series of electric diaphram
pumps died---none lasted longer than six months.

I wouldn't recommend switching to an electric fuel lift pump, because it
adds quite abit of complexity and new points-of-failure.   But if you do,
a rotary pump will last much longer than a diaphram pump. Also, diaphram
pumps made for diesel fuel aren't cheap--so you might as well spend the
money on a good rotary pump.


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I would either use a sight gauge or a Dipstick myself.
« Last Edit: Today at 01:00:29 AM by glort »


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I use a length of clear tubing, marked in 1 qt intervals, from a T at the tank outlet, to a matching T in the diesel return line at the top of the tank. 
I'm using the listeroid tank, set on a shelf, and refill from 5 gal cans.