Liquid fuel preheating means

A preheating system for internal combustion engine fuels. The parts of the system include a heat exchanger through which the fuel passes in heat exchange contact with exhaust gases from the engine, or, in some cases, the engine coolant. Where the heat exchange contact is with exhaust gas, the fuel is vaporized by heat from the gas prior to its introduction into the engine carburetor. Where the fuel passes in heat exchange relationship with engine coolant, it is heated to a point just below boiling before introduction into the carburetor. Where the fuel is heated by exhaust gas, the parts of the system include an accumulator between the heat exchanger and carburetor which serves the purpose of providing a reservoir of the vaporized fuel sufficient to satisfy any demand of the carburetor. The fuel heating system can be employed with a conventional gasoline carburetor where the heat source for the heat exchanger is the engine coolant. Where the heat source is exhaust gas, however, the engine will require the use of a modified butane carburetor in addition to its regular one, in which case the system includes a thermostatically controlled valve that operates to feed gas to the regular carburetor from engine start-up until the exhaust gas reaches a suitable temperature level, then the valve switches the gas flow from the regular carburetor into the heat exchanger. The incorporation of this system into an automobile results in a remarkable increase in engine efficiency and a decrease in exhaust pollutants.

BACKGROUND OF THE INVENTION 
This invention relates generally to fuel preheating means for use on heat 
engines, and more particularly to such means for preheating the gasoline 
fuel of an automobile or the like, prior to its introduction to the 
carburetor of the vehicle, through utilization of waste heat from the 
vehicle's exhaust or, in some cases, from its coolant. 
It is well known that gasoline fuel burns most efficiently in an internal 
combustion engine when it is in the form of a vapor. The conventional 
carburetor does not convert all of the gasoline passing therethrough into 
vapor, a substantial portion being, instead, merely broken up into tiny 
droplets that remain suspended in the intake air when the resulting 
mixture of fuel and air is drawn through the mainfold and into the 
cylinders of an engine. While some vaporization takes place, a substantial 
portion of the gas remains in the form of liquid droplets in the cylinder 
head at the time the mixture is ignited by the spark. These liquid fuel 
droplets burn inefficiently, or incompletely, with the result that the 
engine exhaust contains an excessive amount of unburned hydrocarbons and 
carbon monoxide as air pollutants which contribute to the formation of 
atmospheric smog. Nitrogen oxide is also formed, as a smog producing 
pollutant in the exhaust, because of high combustion temperature in the 
engine, particularly at the point where the exhaust gases pass through the 
exhaust ports during the first few degrees of valve opening. These high 
temperatures are brought about when minute droplets of liquid fuel, still 
unburned, are vaporized by the heat of combustion to mix with the 
remaining oxygen, so that afterwards there is delayed combustion at an 
exceedingly high temperature when the gas is passed between the face of 
the valve and the valve seat. This high temperature is responsible for 
formation of the nitrogen oxide found in internal combustion engine 
exhaust gases. 
In addition to the above-noted disadvantages of the incomplete combustion 
of gasoline brought about by incomplete vaporization thereof in 
carburetors, there is a further disadvantage in the fact that such 
incomplete combustion results in deposits of carbon on interior engine 
surfaces. Furthermore, incomplete fuel combustion is wasteful of energy, a 
serious enough problem in the past but one which is now approaching 
catostrophic proportions because of oil shortages in this country and the 
rising price of imported oil from the oil producing nations. 
Various means for preheating the fuel to automobile engines have been 
proposed in an effort to increase engine efficiency and cut down on 
exhaust pollutants. All such fuel preheating means of which I am aware 
have been designed to provide heat to the fuel as it passes between the 
carburetor and intake manifold of the engine. U.S. Pat. No. 3,762,385 to 
Hollnagel discloses a device adapted to heat engine fuel in this manner. 
While such devices are claimed to increase automobile gas mileages and 
reduce exhaust pollutants, none has yet, to my knowledge, met with any 
substantial degree of commercial acceptance. In view of the critical need 
today for more efficient fuel burning engines, the absence of such 
acceptance of any fuel preheating means heretofore known is clear evidence 
that no such means capable of meeting the stringent demands of the 
marketplace has yet been provided. Moreover, those prior art devices 
adapted to heat gasoline fuel from an engine carburetor prior to its 
introduction into the intake manifold do nothing to reduce or eliminate 
any exhaust pollutants resulting from the presence of additives in 
commercial gasoline fuels. The most common pollutant of this type, to my 
knowledge, is lead, which is spewed out from millions of automobile 
exhaust pipes to poison the atmosphere in the vicinity of heavily traveled 
roadways. 
SUMMARY OF THE INVENTION 
I have now, by this invention, provided unique means for the preheating of 
fuel for a heat engine, having particular adaptability for use on 
automobile engines, to thereby greatly increase the efficiency of the 
engine, and reduce the pollutants in the engine exhaust. My novel 
preheating means differs from any pre-existing fuel vaporizing or heating 
means in that it heats the fuel prior to introduction of the fuel into an 
engine carburetor, as opposed to other systems that heat the fuel between 
the carburetor and intake manifold. The invention takes one of two 
principal forms, the first of which utilizes heat from the engine exhaust 
for the fuel preheating step and the other of which utilizes heat from the 
engine coolant, the latter, of course, being suitable for use only on 
water-cooled engines. 
In its first (exhaust-heat) form, the invention preferably comprises a heat 
exchanger with an internal coil adapted for easy installation in the 
exhaust system of an automobile, and an accumulator through which the 
heated fuel passes on its way to engine carburetor. This embodiment of the 
invention can take the form of a kit for installation of an existing 
automobile, preferably a new one, or it can be incorporated in the car at 
the time of its manufacture. The heat exchanger is simply a cylinder 
housing a coiled fuel line disposed therein, designed for installation in 
the exhaust pipe of a car for use in such fashion as to permit the exhaust 
gases to flow through, in contact with the fuel line, on their way to the 
tail pipe outlet. In passing through the coil, the fuel absorbs sufficient 
heat from the exhaust to cause its vaporization, so that it leaves the 
coil in vapor form. From the coil the vaporized fuel flows into the 
accumulator, which serves as a reservoir in which sufficient volume of 
fuel vapor is retained to satisfy any demand of the carburetor. In this 
version of the invention, a modified butane carburetor is employed to 
meter the vaporized gas from the accumulator to the engine. The 
accumulator, in addition to providing a reservoir for the vaporized fuel, 
serves as a trap for the accumulation of "impurities" in the fuel which 
drop out and collect as a sludge. The bottom of the accumulator has a 
drain with a pet cock or the like which can be opened to drain the sludge 
from time to time. These "impurities" are believed to be additives of the 
type found in commercial gasoline fuels which are not needed after the 
fuel is vaporized in my heat exchanger and would only serve to foul the 
engine and pollute the exhaust. Present among these additives, in the case 
of leaded gas, is tetraethyl lead, which is, I believe, removed in the 
sludge and thereby disposed of as harmless waste. Otherwise the lead in 
the gas would be discharged in the engine exhaust as a poisonous effluent, 
as it is in the case of conventional automobile engines. 
Where the exhaust-heat version of my invention is employed, the 
conventional carburetor for the engine is retained for use from start-up 
of the engine until the temperature of the exhaust gases in the heat 
exchanger reaches a certain level, typically about 300.degree. F., after 
which the fuel is routed through the heat exchanger to the accumulator and 
modified butane carburetor. To insure this type of operation, the system 
is provided with a three-way valve controlled by a thermostat positioned 
to sense the temperature in the heat exchanger. The three-way valve 
interconnects the fuel line from the fuel pump with two outlet fuel lines 
going to the conventional carburetor and heat exchanger, respectively. 
After start-up, while the engine is heating up, the valve automatically 
routes the fuel to the regular carburetor. When the temperature in the 
heat exchanger reaches 300.degree. F., the thermostat actuates the valve 
to route the fuel into the heat exchanger, through which the fuel 
thereafter flows continuously so long as the engine is running. This 
warm-up period, prior to actuation of the valve to route the fuel into the 
heat exchanger, is relatively short, typically about five minutes. As a 
result of the preheating of the fuel to a vapor in the heat exchanger, 
remarkable fuel efficiency, and reduction of exhaust pollutants, are 
achieved. I found, for example, that the use of this system on a 
ten-year-old Mustang with 91,000 miles on it increased the gas mileage of 
the car four or five times over its mileage without the system installed. 
In the second principal (coolant-heat) form of my invention, a heat 
exchanger similar to that described above is employed, but this time 
coolant from the cooling system, rather than exhaust gas, is used as the 
heat source for the fuel. With this version of the invention, the gasoline 
fuel is not vaporized in the heat exchanger, but heated to a temperature 
just below its boiling point. In this state the fuel is passed into the 
regular carburetor of the engine, and, because it is preheated, it 
vaporizes much more completely in flowing into the combustion chambers 
than would otherwise be the case. As a result, the fuel burns more 
efficiently than it would without the preheating, although not as 
efficiently as it does when completely vaporized before entering the 
carburetor, as in the first-described version of my invention. Even here, 
however, I found that the use of my preheating means on the 
above-mentioned Mustang increased its engine efficiency to a sufficient 
extent to double the gas mileage of the car, and substantially reduce the 
pollutants in its exhaust. 
It is thus a principal object of this invention to provide relatively 
simple and inexpensive means for achieving more complete combustion of 
gasoline in internal combustion engines than is possible with conventional 
carburetion systems of the type now in use on such engines. 
It is another object of the invention to provide simple, economical means 
for substantially reducing the air pollutant content of internal 
combustion engine exhausts to thereby bring about a reduction in 
atmospheric smog. 
It is yet another object of the invention to provide such means having the 
additional advantage of trapping the lead constituents of certain gasoline 
fuels to prevent the escape of lead in automobile exhausts to poison the 
atmosphere in the vicinity of busy highways. 
It is still another object of the invention to provide such means in a form 
capable of relatively easy incorporation in a conventional internal 
combustion engine system. 
Other objects, features and advantages of the invention will become 
apparent in the light of subsequent disclosures herein.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Considering now the drawings in greater detail, with emphasis first on FIG. 
1, there is shown generally at 10 a diagramatic view of the parts of a 
preferred fuel preheating system in accordance with this invention 
installed on an automobile for use. The principal parts of the system 
include a heat exchanger 12, an accumulator 14, a solenoid controlled 
three-way valve 16, an even flow check valve 18, and a modified butane 
carburetor 58. The heat exchanger 12 has a cylindrical outer shell 20 and 
an inner coil 22 of tubing wound in a spiral around a rod 24 disposed 
coaxially of said outer shell (see FIG. 3). Into each end of the 
cylindrical shell 20 of the heat exchanger is fitted a round plate 26 
having a tapped central opening 28 into which is screwed a stub conduit 30 
that is threaded at one end to mate with the opening. In addition to the 
opening 28 in plate 26, there is a smaller opening 32 of round 
cross-section sized to snugly receive an end 34 of the tubing from which 
the coil 22 is formed. The rod 24 is supported at the axial center of 
cylindrical shell 20 by means of two pairs of crossing segments 36 of the 
same rod stock as that from which it (rod 24) is formed, the segments of 
each pair being fastened together at right angles to one another, and 
secured to a separate end of the rod, in the manner illustrated in FIG. 3, 
showing the pair of segments at the left end of the rod as there seen. The 
segments 36 are of such length as to fit snugly within the cylindrical 
shell 20, and rod 24 is of the proper length so that when the cross 
segments 36 are attached the resulting part fills substantially the full 
length of the interior of the heat exchanger and will not slide endwise 
therein to cause rattling. 
Secured to rod 24 in spaced apart and parallel relationship are a plurality 
of circular baffles 38. These baffles are disposed perpendicularly to the 
rod 24, and their purpose is to break up the flow of exhaust gases through 
the heat exchanger, as will be explained. They are of small enough 
diameter to fit within the coil 22 which, as FIG. 3 shows, has an outside 
diameter less than the inside diameter of the cylindrical shell 20 to 
permit a loose fit of the coil within the shell. The distance between the 
baffles is not critical, and can vary considerably. Moreover, an optimum 
spacing can be easily determined without difficulty, if necessary, by one 
skilled in the art. The heat exchanger would function even without the 
baffles, although it serves its purpose more effectively when they are 
present. 
The parts of heat exchanger 12 are formed from any material suitably 
resistant to corrosion in the presence of exhaust gases, the otherwise 
satisfactory for the purpose, one example of such a material being steel. 
The end plates 26 of the heat exchanger can be fastened in position at the 
end of shell 20 in any known manner such as, in the case of steel or the 
like, by means of welding. Likewise, the crossed segments 36 of rod stock 
at the ends of rod 24 can be secured in position by welding, or other 
suitable, means, as can the circular baffles 38. The heat exchanger can 
vary in size, but is preferably about three inches in diameter and 
something like fourteen inches long in its presently contemplated form. 
The coil 22 is preferably formed from seamless tubing of about 5/16-inch 
outside diameter, for most cars, and includes a sufficient number of coils 
to require from about ten to about twenty feet of tubing for an exchanger 
of the above-noted size. While, as indicated above, the distance between 
the baffles 38 can vary, this distance, as presently contemplated, is 
preferably about one and a half inches for the average heat exchanger of 
the illustrated type. 
The accumulator 14 is an enclosed, cylindrically-walled vessel with a 
conical bottom 40 at the center of which is a drain outlet 42 fitted with 
a pet cock 44 (see FIG. 4). The accumulator has an inlet fitting 46 about 
half way up its side and an outlet fitting 48 in the center of its top 
enclosure, shown at 50. 
The assembly of parts comprising the fuel preheating system of this 
invention can be manufactured and sold as a kit for installation on an 
existing car, or they can be built into a car during the course of its 
manufacture to become an integral part of the finished automobile. The 
FIG. 1 assembly, in particular, lends itself to manufacture and sale in 
either kit form or as an integral part of a new car. In either event, the 
relationship of the parts of the assembly to the other parts of the car 
will be as diagramatically illustrated in FIG. 1. Thus, as that figure 
shows, the heat exchanger 12 is installed in the exhaust pipe similarly to 
the way a muffler is installed, such a muffler being shown at 52, and the 
exhaust pipe at 54, in FIG. 1. The manner of installation of the heat 
exchanger is such that exhaust gases from the engine pass into the heat 
exchanger housing through the stub conduit 30 at one end, and out of the 
housing through the stub conduit 30 at its other end, the direction of 
flow being as indicated by the directional arrows on FIG. 1. In passing 
through the heat exchanger housing, the exhaust gases impinge upon the 
baffles 38, which deflects them outwardly and into contact with the loops 
of coil 22. 
As previously indicated, the fuel preheating assembly or system of FIG. 1 
requires the use of a modified butane carburetor in addition to the 
regular carburetor of an automobile engine, the regular carburetor being 
shown at 56 and the modified butane carburetor at 58 in FIG. 1. The 
modification of the butane carburetor (a standard part) involves reduction 
of the sizes of the idle and intake jet openings and increase of the air 
intake opening, and can be easily accomplished by one skilled in the art 
in the light of present teachings. More specifically, I have found that 
reduction of the idle jet opening from 0.089 to 0.046 inch, reduction of 
the intake jet opening from 0.312 to 0.208 inch and increase of the air 
intake opening to one and three quarter inches is normally adequate for 
the purpose. I do not wish to be limited, however, to these particular 
opening size modifications, since other modifications can be made within 
the scope of my invention. Conventional butane carburetors are made with 
pot metal parts, since these are satisfactory for use with butane. Because 
the vaporized gas from the heat exchanger coil is, as will be seen, fairly 
hot, however, it is preferable to further modify the butane carburetor for 
my purpose by substituting steel parts for most of its pot metal parts. 
Still another modification of the conventional butane carburetor that I 
have found useful for my purpose is the substitution of a mechanically 
operated brass diaphragm for its automatically operating pot metal one. 
The modified butane carburetor 58 is mounted on the intake manifold of the 
engine (not shown) serviced by the regular carburetor 56. Here, as in the 
case of the various other parts of the FIG. 1 assembly, the installation 
details are omitted since one skilled in the art would have no difficulty 
in mounting the carburetor (or other part) in the proper position for use 
in view of present teachings. In this, as well as all other installation 
procedures required for the various parts of the FIG. 1 assembly, standard 
procedures, hardware and tools well known to any mechanic can be employed. 
Furthermore, all such procedures are well within the skill of any such 
mechanic. 
In the FIG. 1 assembly, a fuel line 60 connects the engine fuel pump, shown 
at 62, to the even flow check valve 18, and another line 61 runs from the 
check valve to the three-way valve 16. Another fuel line 64 extends from 
the three-way valve to the regular engine carburetor 56. Still another 
fuel line 66 interconnects a second outlet opening from the three-way 
valve 16 with one end of the tubing coil 22 in heat exchanger 12. The fuel 
line 66 is connected to the coil at the appropriate end 34 by means of a 
standard connector or fitting. In like manner, a fuel line 68 is connected 
to the other end of the coil, and runs to the accumulator 14, where it is 
connected to the inlet fitting 46 thereof. Finally, a fuel line 70 is 
connected to the outlet fitting 48 of the accumulator and runs to the 
modified butane carburetor 58. 
A thermostat 72 is mounted on the heat exchanger 12 in such fashion as to 
sense the exhaust temperature within the heat exchanger. This thermostat 
is connected in circuit with the solenoid controlled three-way valve 16 by 
means of a conductor cord 74, and to a solenoid controlled butterfly valve 
76 by means of a second conductor cord 78. The threeway valve 16 is 
normally closed to the flow of fuel from the fuel pump into line 66, and 
the butterfly valve 76 is installed in a branch air intake tube 80 to be 
desired in greater detail below. The thermostat 72 is designed to open the 
three-way valve 16 to the flow of fuel into fuel line 66 when the 
temperature within heat exchanger 12 reaches a certain level, soon to be 
revealed, and to open the butterfly valve 76 when that temperature reaches 
a still higher level, also soon to be revealed. Thermostats of this type 
are commercially available and familiar to those skilled in the art. 
The manner in which the FIG. 1 assembly functions will now be described. 
When the engine of the car on which the assembly is installed is started 
cold, the temperature within the heat exchanger 12 is below the level at 
which the thermostat 72 opens three-way valve 16 to fuel flow into the 
heat exchanger. The three-way valve, at this point, is open to the flow of 
fuel into the line 64 leading to the regular carburetor 56. Consequently, 
the fuel passes through this carburetor and into the intake manifold of 
the engine. After the engine has run a few minutes, normally, as 
previously indicated, something like five minutes, the exhaust gases 
passing through heat exchanger 12 reach a temperature of about 300.degree. 
F. This is the temperature level at which thermostat 72 opens the 
three-way valve 16 to the flow of fuel into the heat exchanger. The fuel 
now flows through the coil 22 in heat exchanger 12 and is vaporized, then 
passes through fuel line 68 to accumulator 14. From accumulator 14, 
vaporized fuel flows through the fuel line 70 into the modified butane 
carburetor 58. From the modified butane carburetor, the fuel, in vapor 
form, enters the intake manifold of the engine for combustion as a 
completely dry fuel. 
It is desired to keep the vaporized fuel below a certain upper temperature 
limit, and for that purpose the above-mentioned air intake tube 80 and 
butterfly valve 76 are installed in the FIG. 1 assembly. As FIG. 1 shows, 
the air intake tube 80 is merely a branch conduit open at its outer end 
and connected at its inner end to the exhaust pipe 54 for the admission of 
cool outside air into the exhaust gases in the exhaust pipe, under 
controlled conditions, to lower the temperature of the exhaust stream 
entering heat exchanger 12. To this end, the thermostat 72 is set to open 
the butterfly valve 76 when the temperature within the heat exchanger 
reaches 550.degree. F. Thus, the thermostat will see to it that cooling 
air is sucked into the exhaust stream whenever the temperature within the 
heat exchanger is 550.degree. F. or above, to maintain the temperature of 
the vaporized fuel within desired limits. The above-mentioned temperature 
limits (300.degree.-550.degree. F.) are preferred limits for use in the 
FIG. 1 system, although they can vary within the scope of my invention so 
long as the system is functional in the manner taught herein. 
The FIG. 2 fuel preheating system is of simpler character than that of FIG. 
1, and intended primarily for installation on used cars. While it does not 
bring about the fuel economy and pollution control of the FIG. 1 assembly, 
it nevertheless results in great improvement in both fuel economy and 
pollution control by comparison wih normal car performance. In the FIG. 2 
system, a heat exchanger 82 is connected into the coolant lines to the car 
heater, by means of a pair of tees 84 and two water lines 86 and 88, in 
the manner illustrated in the drawing. From the fuel pump, shown at 92 on 
FIG. 2, fuel passes through a fuel line 90 to an even flow check valve 94, 
and from there, through another line 91, to the heat exchanger 82. During 
operation of the FIG. 2 engine, not shown, fuel passes through the coil in 
the heat exchanger, which is identical to that in the heat exchanger coil 
of FIG. 1, and from there, through a fuel line 96, to a filter 98, from 
whence it flows to the regular engine carburetor, shown at 100, through a 
line 97. 
When the engine is started up cold, the fuel first passes though the heat 
exchanger and on into carburetor 100 without being preheated. Soon, 
however, the engine coolant heats up and eventually reaches a maximum 
temperature controlled by the usual thermostat in the coolant system, 
whereat it raises the temperature of the fuel in the heat exchanger to the 
same level. In the FIG. 2 system, vaporization of the fuel is not desired 
since the conventional gasoline carburetor 100 is designed to receive 
liquid fuel and will not function properly if the entering fuel is in the 
form of a dry vapor. Consequently, the thermostat controlling the coolant 
temperature should preferably be set at about 180.degree. F., since 
gasoline boils at 187.degree. F. Fuel passing through the heat exchanger 
thus leaves that unit at about 180.degree. F. and reaches the carburetor 
100 at a temperature close to the boiling point, but still in liquid form. 
As a result of its high temperature, the fuel is fed to the engine in such 
condition as to rapidly vaporize and burn more efficiently than it does 
when it enters in atomized form as in the case of conventional carburetion 
where no fuel preheating is accomplished. While the presence in heat 
exchanger 82 of the baffles corresponding to baffles 38 of heat exchanger 
12 (FIG. 1) help to improve the heat transfer efficiency of the unit (heat 
exchanger 82), those baffles could be omitted, if desired, since the unit 
will function fairly well without them in the FIG. 2 system. 
The presence of the even flow check valve 18 in the FIG. 1 system, and the 
similar check valve 94 in the FIG. 2 system, is necessary to prevent the 
back flow of fuel into the fuel pump should the pressure in the line 
exceed that generated by the pump. Thus, if such excessive pressure 
developed, it would cause the check valve to close till the pressure again 
dropped to a level below that generated by the pump, at which point the 
valve would again open to permit the flow of gasoline therethrough. 
I have determined experimentally that the accumulator in the exhaust-heat 
version of my invention functions very effectively to remove certain 
unwanted components of the vaporized fuel which drop out to form a dark 
syrupy sludge therein. These components are, I believe, at least in part, 
the various additives found in commercial gasoline fuels. To illustrate 
the effectiveness of the accumulator in this regard, during a rather 
limited test run recently conducted by me, a layer of sludge about half an 
inch deep formed in an accumulator employed for the run. FIG. 4 shows, at 
102, a deposit of such sludge in accumulator 14. This sludge can be 
readily removed from the accumulator by opening the pet cock 44 and 
allowing the material to escape through drain 42. For obvious reason, the 
pet cock should be opened periodically to allow the accumulator to drain, 
but this operator is so simple that anyone, even a child, can easily 
perform it without difficulty. 
Following are examples which are included to illustrate the effectiveness 
of the fuel preheating means of this invention in increasing the fuel 
economy of an automobile engine and reducing the pollutants in the engine 
exhaust. It is to be understood, of course, that these examples are 
included for illustrative purposes only. 
EXAMPLE I 
In this example, the above-mentioned automobile (1967 Ford Mustang with 
over 90,000 miles on it) was tested for gas mileage in its normal 
condition and found to run 11.2 miles per gallon under city driving 
conditions. Under highway driving conditions, the engine achieved 20 miles 
per gallon of fuel. 
EXAMPLE II 
The 1967 Mustang employed for the Example I test was again tested for gas 
mileage, this time fitted with a preheating system in accordance with this 
invention utilizing hot water from the coolant system as the heat source 
at a controlled temperature of 180.degree. F. The same test conditions as 
those of Example I were employed--the gas mileage under city driving 
conditions was found to be 23.2 miles per gallon, and under highway 
driving conditions, 32 miles per gallon. Thus, the use of the coolant-heat 
version of my invention was found to increase the mileage of the car under 
city driving conditions by more than 100%, and under highway driving 
conditions, by 60%. These results are better than the 1985 mileage 
standards, and were achieved even with the less efficient (coolant-system) 
version of the two principal forms of my invention. 
EXAMPLE III 
The 1967 Mustang tested in Examples I and II was fitted with preheating 
means in accordance with this invention utilizing the exhaust gases of the 
car at a temperature of from 450.degree. to 500.degree. F. as the heat 
source. The car, thus equipped, was tested for gas mileage by the method 
employed in Example I and found to have a gas mileage of 40 miles per 
gallon under city driving conditions, and 73.6 miles per gallon under 
highway driving conditions. This example demonstrates that the use of heat 
from exhaust gases as the heat source for my novel preheating means 
increased city driving mileage on a ten-year-old car by almost 250%, and 
the highway driving mileage by almost 550%. These results clearly show 
great superiority of performance of my fuel preheating means over any 
other known preheating means, at least among those of which I am aware. 
EXAMPLE IV 
The aforesaid Mustang equipped with the exhaust-heat version of my 
invention was tested at a California State facility for measuring the 
pollutants in automobile exhausts, with the following results (average 
idle, low cruise and high cruise results). Tabulated with these results 
are the present-day California standards (idle, low cruise and high cruise 
average) for exhaust pollutants. These standards are for 200 cubic-inch 
engine cars, within which category my Mustang falls. 
TABLE I 
______________________________________ 
Exhaust Emissions 
Unburned 
Hydro- Carbon Nitrogen 
carbons Monoxide Oxide 
(HC) (CO) (NO) 
______________________________________ 
1967 Mustang equipped with 
preheating means utilizing 
exhaust gases as heat 
source .00157 1.07 .00842 
California emission 
standards (1977) 
.00466 4.66 .250 
______________________________________ 
Note: 
Pollutant quantities are given in grams/mile. 
The results of this example show that my novel fuel preheating means 
enables even a ten-year-old car with high mileage, and (obviously) no 
catalytic converter, to achieve emission pollutant levels far below those 
allowed by present-day California standards, the most stringent in the 
nation. Thus, the ten-year-old test car of this example produced exhausts 
with an average unburned hydrocarbon content equal to only about one-third 
of that permitted by the California emission standards. The average carbon 
monoxide content of the exhaust was even lower, relatively speaking, the 
quantity of carbon monoxide there being less than 23% of the permissible 
quantity under the California standards. The reduction in nitrogen oxide 
content below the California standards level was truly remarkable in this 
example, the average amount of that extremely harmful pollutant in the 
test car exhausts having been found to be only 3.2% of that permitted by 
the standards. 
My novel fuel preheating means has certain advantages in addition to those 
specifically mentioned above. For one thing, its use obviously does away 
with any need for catalytic converters, thereby eliminating the various 
problems resulting from the use of such converters. For another, when 
installed on a used car, it quickly cleans carbon deposits from the car's 
engine, and when built into a new car it prevents the formation of such 
deposits. Cars equipped with my novel preheating means are as free from 
explosion and fire hazard as are conventional automobiles since fuel 
pressures are kept within the same limits in both cases, fuel systems 
incorporating the preheating means are sealed against leakage and no 
temperatures are greater than ordinary manifold temperatures where such 
systems are employed. 
As will be apparent from the foregoing, any gasoline fuel will suffice for 
purposes of my invention, and particularly the exhaust-heat versions 
thereof. Since the fuel is vaporized prior to combustion, it burns cleanly 
and efficiently in engine combustion chambers, causing no ping, regardless 
of its octane rating or quality. Thus, any low grade gasoline fuel, even 
white gasoline of the type heretofore used in gasoline lanterns, could be 
satisfactorily burned in engines equipped with exhaust-heat preheating 
means in accordance with this invention. 
While my novel fuel preheating means has been herein described and 
illustrated in what I consider to be preferred embodiments, it will be 
appreciated by those skilled in the art that my invention is not limited 
to those particular versions, but is broad enough in concept to encompass 
all modifications thereof incorporative of the structural and functional 
essence of the invention as taught herein. Some of those modifications 
have been previously discussed, and others will be evident to those 
skilled in the art in the light of present teachings. An example of 
something akin to the latter would be the use of a coil made of a highly 
heat conductive metal such as copper, rather than steel, in heat exchanger 
82 of FIG. 2. 
Although I have herein stressed the applicability of my novel fuel 
preheating means for use on gasoline burning automobile engines with 
carburetors, it should, of course, be understood that the fuel preheating 
means has broader use potential than this, and can be employed in any 
capacity for which its unique character suits it. For instance, it can be 
used on internal combustion engines with carburetors other than car 
engines, examples of which include motorcycle, snowmobile, lawn mower, 
etc., engines. In some form, fuel preheating means in accordance with the 
principles of this invention could be found that would have applicability 
for use on any engine with a heat source available for tapping, such as, 
for example, a fuel injection engine, a rocket engine, or the like. 
In summary, it is emphasized that the present invention includes within its 
scope all variant forms thereof encompassed by the language of the 
following claims.