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This gas injection system
utilises a sophisticated computer module that controls the
flow of LPG into mechanical and electronic diesel engines
whether stationary or mobile, turbocharged or naturally
aspirated.
The system operates by simultaneously burning diesel
with a small quantity of gas resulting in a more
efficient burn rate of 95%-98% (most diesel
engines achieve around 75-85%). This increase in the burn
rate results in less diesel being used to create the same
outcome.
Best of all, no engine modification is required, the system
is non-invasive, operates completely independently, is
simple to fit and can be fine-tuned to your requirements.
High-pressure liquid
petroleum gas (LPG) is converted to a low-pressure (just
above atmospheric) useable gas. The gas passes through a
solenoid valve (or stepper motor) which is controlled by
outputs from the system’s computerised processor
measuring precisely the quantity of gas required.
This metered amount of vapour travels through a hose into
the vehicle air intake system and subsequently into the
inlet manifold as a mixture of air and gas.
The computer module (processor) controls the flow of gas
optimising performance and ensuring safety. Manifold
pressure (via a MAP sensor) or throttle position (via a
throttle position sensor) and engine speed are monitored.
The module then adjusts the gas flow depending on engine
load and driver demand. The amount of gas injected (or the
‘gas map’) is completely (and only) programmable by
a laptop computer. This allows a large degree of
flexibility to adjust the system to suit your requirements.
The system does not allow LPG into the engine at idle and is
programmed to limit the amount of gas introduced at maximum
load to prevent over-fuelling. The system
shuts off gas flow when the brakes are applied or the
driver’s foot comes off the accelerator.
The system can be switched on and off (if ever necessary)
via a dash mounted switch. If gas is unavailable or you run
out before a service station, it is not necessary to switch
the system off. Instead you will notice a decrease in
performance as the gas runs out. Since the diesel injection
system is not modified, the vehicle will simply run
on diesel as it did prior to the system being
fitted.
As a result of the
increased efficiency created by burning more of the diesel
injected into the combustion chamber, less diesel is
now required to travel each kilometre, therefore
extending the range travelled on each tank
of diesel. Or, to look at it another way, the same amount of
diesel will deliver more power and torque.
Documented evidence indicates net fuel cost savings
of 10-20% are achievable running on either
bio-diesel or normal diesel. A 4x4 vehicle will use
approximately one litre of LPG for every 25-30 kilometres
travelled under normal driving conditions. For further
explanation, see Economy section.
This Diesel/Gas system
will increase power and torque by up to 20%
(sometimes more). This power increase is due not only to the
increased combustion efficiency, but also the LPG itself
produces power as it burns. So even the most economical gas
map and driving technique will produce some additional
power. A more powerful setting can still produce better
economy than running on straight diesel.
This extra power is instantly noticeable from the moment the
system is turned on. However, as the engine clears carbon
deposits over time it is not unusual for the advantages of
the system to increase.
Image to the left is of a power run with the Patrol on the
Dyno
The power and torque increase applies
over the whole rev range. Turbo lag is all but eliminated,
and engine noise and vibration is dramatically reduced all
the way through to maximum revs. The driver will notice
fewer gear changes and higher
average speeds, particularly on hills and when
towing.
See Vehicles section for examples of power gains.
For those of you with
experience with LPG vehicles, you would know the engine oil
stays much cleaner between oil changes. LPG engines, when
stripped, are almost spotless internally. On the other hand
diesel engines are quite dirty internally and after an oil
change the new oil quickly becomes black again.
In a diesel engine this black stain is soot. Soot is the
result of incomplete combustion (the same as any wood fire
stove). This soot (which is actually carbon) gathers in the
combustion chambers, lining the top of the pistons, the
injectors, the glow plugs and the valves. Some stays there
and builds up into thick carbon deposits that must be
scraped away when the engine is stripped. Some is blown into
the exhaust manifold, coating the inside of the exhaust pipe
or blown out the back as black smoke. The rest is washed off
the cylinder walls by the engine oil, thus contaminating it
and turning it black. This is why engine oil filtration is
critical in diesels.
With enough carbon contamination, oil
soon loses its ability to lubricate (viscosity) and clean
properly, leaving abrasive deposits on critical components
and allowing further carbon build-up. This causes engine
wear - hence the need to change the engine oil on a regular
basis. Anyone who changes their own oil will tell you that
with diesels the oil becomes very black, very quickly. This
indicates that the oil is doing its job but it is also
already breaking down and losing its effectiveness long
before the next oil change is due.
Image above is of Heavily contaminated diesel sump oil after
5000 km
Since LPG is a clean burning gas it does not leave soot
behind. This is why the engine and oil stay cleaner for
longer. With the Diesel/Gas system cleanliness is achieved
slightly differently. The gas introduced acts as a catalyst
encouraging a more complete diesel combustion. This means
less soot (a lot less soot) which, in turn, means the oil
stays cleaner. Now, if the oil is staying cleaner, that
means it is not carrying as much contamination, and is
therefore doing its job better and for longer. The
upshot is reduced engine wear between oil changes
and over the life of the engine (which is extended as a
result).
Engine operating temperatures are not increased by running
this system. Exhaust gas temperatures are reduced,
since there is no longer fuel being burnt in the exhaust
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