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“The Fuel Stretcher” is a device that allows the use of
supplemental propane or compressed natural gas on turbodiesel engines. When propane
or cng is
injected into the air intake of a turbodiesel, it reduces the
amount of diesel fuel necessary to produce the needed power. It
is basically substituting propane or cng for some of the diesel fuel.
This is also called fumigation. The engine must always use
some diesel fuel, because the diesel fuel ignites the gas.
The Fuel Stretcher allows the user to adjust the amount of gas
consumed from very little to approximately two to three gallons
of gas to every gallon of diesel fuel. This can amount to
a substantial reduction of the operating cost per mile.
The gas also increases the power output of the engine. Another
side benefit is much lower emissions and less lubricating oil
contamination.
The
Fuel Stretcher comes as a complete kit with easy to follow
instructions for installation. The only additional item you
need is a propane or cng tank.
Theory of Operation
No gas is
used when the engine is idling. A hose is connected from the
regulator to the air intake between the air cleaner and the
turbo. When the engine load increases, the turbo creates
an increasing vacuum in the air pipe. This vacuum
activates the propane regulator to begin supplying fuel. As the
engine load continues to increase, the vacuum continues to
increase, causing the regulator to supply more and more gas.
A flow control valve in the fuel vapor line controls the overall fuel
curve. A dash mounted switch turns the unit
on and off, and it also turns on and off with the ignition
switch. The unit draws liquid propane from the tank to
eliminate pressure loss due to evaporation within the tank.
Consequently, the unit is water heated and is connected in
series with the heater core. The kit includes all necessary
hoses and hardware to make this connection.
Operation on a
GM Duramax has given as much as 60 miles per
gallon of diesel fuel. At this consumption rate, the propane
consumption was approximately 20 miles per gallon. Another
great benefit is that it will add up to 100 rear wheel
horsepower.
CNG,
(compressed natural gas) is now available to supplement diesel
fuel for turbodiesels. Comparable results to propane have
been achieved. For more information, go to
this page.
We are
developing a microcontroller for the injection unit that has
exhaust temperature input, detonation sensing, and fuel
level. The controller will retard gas flow as exhaust
temperatures reach a user adjustable threshold. The
detonation sensor will also retard gas flow to avoid engine
damaging detonation which accompanies use of large amounts of
gas. A pressure transducer will report fuel pressure
which will be shown on the display as gallons of fuel
remaining. Steady highway driving has yielded as much as
400 mpg on diesel, which is approximately 96% CNG
operation. This is at light load. Typically it is
difficult to avoid detonation using more than 70% under heavy
load. Check back occasionally for updates on the progress
of the microcontroller. We hope to have something
available by late fall '09.
If you would
like more information, please call DeLuca Fuel Products at
740-622-7942, or email us at marc@delucafuelproducts.com.
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