GTA’s Fuel Technology for Two-cycle Engines
Summary
The two-cycle engine is commonly used
for personal transportation on land and water and for many other applications.
It has become the major cause of air pollution in many areas around the world.
Newer, cleaner burning engines are being designed and may be a long term
solution but they are not an answer for today. GTA has a product which modifies
the two-cycle engine’s fuel to make it burn cleanly and more efficiently. It
offers an immediate low-cost solution to the two-cycle pollution problem while
it pays the consumer back in improved fuel economy.
The
Two-cycle Engine Problem
Two-cycle engines have many advantages
over four-cycle engines which make them ideal for use in motorcycles and
outboard motors. For a given engine displacement it is lighter, smaller,
produces more power and has fewer moving parts. As a result it is less expensive
to manufacture, and it can be fitted to smaller, lighter chassis. The two-cycle
engine is also more reliable and easier to maintain than a four-cycle engine.
Two-cycle engines, however, have a very
important disadvantage. They are inefficient and produce more emissions of
carbon monoxide and unburned hydrocarbons. It is reported by environmental
groups that 30% of the fuel used by two-cycle engines goes out the exhaust. This
results not only in a loss of energy, but the harmful emissions are so high that
the two-cycle motorcycle is being banned from road use in the United States and
new EPA regulations will effectively ban it from use in outboard motors. The
loss of energy means that more fuel needs to be burned to make up for that loss.
The power capacity of the engine is also a victim of incomplete combustion.
Engine manufacturers are working to
develop lower polluting substitutes for the two-cycle.
Smaller four-cycle designs and modified two-cycles are being developed.
The new engines will be more expensive, more complicated and will not
have many of the advantages of the current two-cycle.
Causes
of Inefficiency and High Emissions From Two-cycle Engines
The inefficiency and high emissions
from two-cycle engines are attributable to the basic way a two-cycle operates.
Unlike a four-cycle engine which has separate fuel intake and exhaust strokes,
in a two-cycle the fuel/air mixture enters the cylinder at the same time spent
gasses are exhausted. Mixing of the
new fuel and the spent fuel gasses occurs causing non-uniform and incomplete
combustion of the new fuel. The two-cycle pollution problem is compounded by the
fact that lubricating oil is mixed with the fuel and must be burned along with
it.
An additional and less well-known cause
of inefficiency and high emissions is attributable to a basic property of
gasoline which interferes with formation of a homogeneous fuel/air mixture in
the cylinder. Gasoline is comprised of many different components which boil off
or vaporize at different temperatures. Some vaporize almost immediately after
entering the intake system. Some remain a liquid well into the combustion
process. What is happening is that
components which vaporize at low temperatures leave behind droplets that
vaporize only at much higher temperatures. This is called fractional
distillation. The important point is that the gasoline phase of the fuel/air
charge in the cylinder of an engine is not homogeneous. It has been demonstrated
that this lack of gasoline component homogeneity leads to incomplete combustion
and emissions. While the fractional distillation problem is common to two- and
four-cycle engines, it is more pervasive in the two-cycle where the fuel
contains very slow burning lubricating oil molecules and where the fuel mixes
with spent gasses.
GTA’s
Fuel Technology
GTA has proprietary technology which
can be used to bridge the gap between today’s inefficient, high-emission,
two-cycle engine and future cleaner designs. GTA uses a scientific phenomenon
called viscoelasticity to solve the fractional distillation problem.
Viscoelasticity means that a liquid can be made to have much greater viscosity
when it is stretched, as in a spray. GTA uses a very small amount of high
molecular weight polymer to make fuel viscoelastic. Fuel droplets formed when
fuel is pulled from a carburetor instantaneously become viscous. The increased
viscosity holds in the components which would normally escape and turn to vapor
and fractional distillation is inhibited. Fuel droplets maintain their integrity
until they are mixed with air in the cylinder where the heat is sufficient to
vaporize all components simultaneously from the surface of the droplet. Slow
burning fuel and oil molecules are burned simultaneously with more volatile fuel
components. The result is a more uniform flame front and more complete
combustion. Emissions and fuel consumption are reduced and power is increased.