Combustion system for internal combustion engines

A unique process is disclosed for modifying an automobile engine to improve fuel economy and reduce harmful exhaust emissions by introducing water and an oxidizing agent, such as hydrogen peroxide, when the engine is under load. The carburetor of a standard engine is adjusted to provide a very lean air-fuel mixture and to increase the air-fuel ratio substantially (e.g., 10 to 20 percent). The amount of hydrogen peroxide injected into the engine depends on the rate of fuel flow and may be regulated by the throttle valve or intake manifold pressure. Means are provided for maintaining a supply of hydrogen peroxide including a high pressure mixing tank containing water and hydrogen peroxide and a pair of removable oxygen tanks for a continuous supply of oxygen to the tank.

BACKGROUND OF THE INVENTION 
During the last decade vast sums have been spent in an attempt to improve 
the gas mileage in modern high-compression automobile engines. Attempts 
have been made to operate the engines with lean fuel-air mixtures and 
lead-free gasoline, but it has been difficult to obtain satisfactory 
performance in this way because of ignition or combustion problems when 
the air-fuel ratio is high, particularly when it exceeds 17 to 1. It is 
also difficult to avoid knocking and to achieve good all around 
performance in lean-burn engines using lead-free or low octane gasoline 
and compression ratios such as 9:1 to 10:1 or higher. 
Ignition problems are less severe in a lean-burn engine when torch ignition 
is employed as in Honda-type engines which have the spark plug located in 
an auxiliary combustion chamber. However, the combustion problem is still 
a limiting factor and the engines cannot operate satisfactorily with an 
air-fuel ratio of 20 to 1. The large amounts of nitrogen apparently 
interfere with proper combustion. 
SUMMARY OF THE INVENTION 
The present invention solves the above problems by injecting a 
nitrogen-free oxidizing fluid, such as hydrogen peroxide, into the engine. 
This combined with water injection makes it possible to operate a modern 
high-compression engine at a high air-fuel ratio, such as 18:1 to 20:1, 
when using lead-free or low octane fuel. 
The invention applies to all types of internal combustion engines and can 
be employed to modify existing engines. For example, an existing 
automobile can be modified by adjusting or changing the main discharge jet 
to provide a leaner fuel-air mixture and by providing means for injecting 
water and hydrogen peroxide into the carburetor in accordance with engine 
load. The flow of the hydrogen peroxide may be easily regulated by a valve 
responsive to movement of the gas pedal or throttle valve or responsive to 
intake manifold pressure. 
A continuous supply of hydrogen peroxide can be maintained by providing a 
high pressure mixing tank containing water and hydrogen peroxide and by 
supplying pure oxygen to the top of the tank from one or more oxygen 
tanks. 
Optionally, oxygen from the tanks may be introduced into the combustion 
chamber of each cylinder to promote ignition during starting or operation 
of the engine. 
The invention is also applicable to lean-burn Honda-type engines having an 
auxiliary carburetor and having an auxiliary combustion chamber for each 
cylinder. The torch ignition principle plus hydrogen peroxide injection 
into the main carburetor or into the main combustion chamber makes it 
possible to operate with extremely high air-fuel ratios. 
The process of this invention improves the efficiency of the engine and 
minimizes air pollution. It permits use of lead-free gasoline, gasolines 
of various octane ratings, and various gasoline mixtures. The gasoline may 
be mixed with substantial amounts of alcohol or with small amounts of 
various other fuels such as a nitroparaffin, a naphthene or an olefin; but 
conventional gasolines are usually preferred.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The process of the present invention may be applied to any conventional 
high-compression automobile engine and particularly the common 
reciprocating-piston internal combustion engine. FIG. 1 illustrates one 
embodiment of the invention wherein the invention is applied to a 
conventional in-line, four-stroke, six cylinder, overhead-valve automobile 
engine A having a cast iron cylinder block 1 with pistons 2 arranged to 
drive the crankshaft (not shown) through connecting rods 3. The pistons 
reciprocate in the vertical cylindrical bores 4 of the cylinder walls 5 
which are cooled by water or other liquid coolant from the radiator (not 
shown). A conventional cylinder head 6 is mounted on the top of the engine 
block 1, and an oil pan 7 is mounted on the bottom of the block. An intake 
manifold 8 and an exhaust manifold (not shown) are mounted on the cylinder 
head. The air passes through an air cleaner 9 to a carburetor 10, where it 
is mixed with fuel, and the air-fuel mixture passes to the intake 
manifold. The carburetor receives gasoline from the fuel pump (not shown) 
through a fuel line 21. The flow of air is controlled by a choke valve 11 
and a throttle valve 12 and the fuel flow is regulated by the carburetor 
in the conventional manner by means of a Venturi 13 and associated fuel 
metering means. 
The carburetor 10 may be of conventional construction (except for the 
auxiliary discharge nozzle 20) and may, for example, be a standard Carter 
carburetor of the type commonly used in passenger cars during the last 2 
decades. As shown, the carburetor has the usual idle air passage 14 and 
idle discharge passage 15 and an idle adjusting screw 16 which may be 
turned to enlarge or restrict the opening at the discharge passage. The 
latter passage is located at or slightly below the throttle valve when the 
valve is closed, and the air-fuel mixture passing through passage 14 is 
preferably somewhat rich to facilitate idling at low speeds and starting 
the engine. 
The carburetor 10 has the usual float chamber housing 17 providing a 
reservoir of fuel and containing a float to maintain the fuel at the 
proper level. A main discharge jet 18 is located within the Venturi 13 at 
the upper end of an inclined discharge tube 19 which extends from the 
bottom of the float chamber. The tube may contain a metering orifice to 
regulate the flow of fuel, and the fuel flow is such as to provide a lean 
air-fuel mixture for normal engine operation. 
In accordance with the present invention the carburetor is constructed 
and/or adjusted to provide a higher air-fuel ratio than would be provided 
by the main discharge jet 18 according to conventional practice and a 
special discharge nozzle 20 is provided for injecting an oxidizing agent, 
such as hydrogen peroxide. The invention is illustrated as applied to a 
conventional downdraft carburetor, but it will be understood that other 
types of carburetors can be used. 
The invention may be applied to various types of engines including rotary 
engines and compression ignition engines, but is shown applied to a simple 
spark-ignition engine having cam-operated intake and exhaust valves for 
each cylinder. As shown the intake valve 23 is arranged to move into and 
out of contact with the valve seat 22 to admit the air-fuel mixture from 
the intake manifold 8 to the combustion chamber 24 of each cylinder. The 
valve actuating means is located under the valve cover 25 and may, for 
example, be of the general type illustrated in FIG. 2. 
The engine shown herein is a standard type of water-cooled automobile 
engine with a fan 26 driven from the crankshaft by a fan belt 27 and 
water-pump pulleys 28. The engine has a transmission 29 and is mounted in 
an automobile having a firewall 40. 
In accordance with the invention, auxiliary means are provided for 
supplying hydrogen peroxide to the engine which may include a liquid 
supply tank 30, a motor-driven injection pump 31, a mixing tank 32, valves 
33 and 34, and a pair of oxygen tanks 35. 
The tanks 30 and 35 are removable and are shown as being supported in 
inverted positions by suitable brackets 36 and 37, respectively. The tank 
30 has a fitting 38 detachably connected to a supply conduit 39 which 
extends to the inlet of pump 31. The pump discharges to the tank 32 
through discharge conduit 41 and maintains a high pressure on the liquid 
in the tank. 
The motor of the pump may be controlled in accordance with the liquid level 
and/or the pressure in the tank 32 to maintain the necessary liquid 
pressure. As herein shown, a float 42 and a float-operated control unit 43 
are provided for controlling operation of the pump 31 to maintain a 
constant liquid level in the mixing tank 32. Where the pump is driven by 
an electric motor, the unit 43 may start and stop the motor in accordance 
with the position of the float. 
As shown, a pair of oxygen tanks 35 are provided for supplying oxygen to 
the upper part of the tank 32 through the conduits 44 and 45. Each tank 
has a fitting 46 detachably connected to the associated conduit 44 and a 
valve 47 for controlling flow of oxygen from the tank. The second oxygen 
tank is optional but is preferred. 
The pressure in the tanks 35 may be 20 to 50 atmospheres or higher, and the 
mixing tank 32 is designed to withstand such pressures. The pressure on 
the liquid must be reduced before it is injected into the carburetor 10, 
and a pressure reducing means is provided for this purpose. For example, a 
constant pressure valve 33 may be provided in the conduit 48 leading from 
the tank 32 to maintain the pressure at the outlet side of the valve 33 at 
a predetermined value, such as 5 to 10 pounds per square inch. The valve 
33 is responsive to the outlet pressure and closes when that pressure 
exceeds said predetermined value. 
The control valve 34 is provided between the conduit 48 and the conduit 49 
to regulate the flow of liquid to the discharge nozzle 20 at the end of 
conduit 49. The valve 34 may be opened and closed in response to movement 
of the throttle valve 12 or in response to the pressure in the intake 
manifold 8 so that hydrogen peroxide and water are injected into the 
carburetor when the throttle 12 is opened and the engine is under high 
load. As herein shown, the valve 34 is a spool-type valve operated by a 
diaphragm 50 responsive to intake manifold pressure. The valve has a spool 
valve member 51 connected to the diaphragm and mounted to reciprocate in a 
cylinder 52. The bottom portion of the valve member has a recess to 
receive a spring 53 and the middle portion has an annular peripheral 
groove 54 with an axial length sufficient to establish communication 
between the inlet opening 55 and the outlet opening 56 when the valve is 
in the open position. 
The diaphragm 50 is mounted in a housing having an upper chamber 57 with a 
vent opening 58 and a lower chamber 59 with a conduit 61 connected to the 
intake manifold 8. At low loads with the throttle 12 near the closed 
position, the subatmospheric pressure in the intake manifold and in the 
chamber 57 causes the diaphragm 50 to move downwardly and compress the 
spring 53, thereby closing the outlet 56 as indicated in FIG. 1. Under 
high load with the throttle 12 opened wide, the pressure in the intake 
manifold increases and the difference in pressure between chambers 57 and 
59 decreases so that the spring 53 can move the valve to the open position 
and admit liquid from conduit 48 to conduit 49. Thus liquid is injected 
through the nozzle 20 whenever the engine is operated under a high load, 
for example when the automobile is accelerating or going up a hill. 
The process of operating the engine of FIG. 1 is described in more detail 
hereinafter, it being understood that such process can be applied to 
engines quite different from those illustrated herein. 
FIG. 2 is a fragmentary view showing another embodiment of the invention 
wherein the hydrogen peroxide or other oxidizing agent is injected at the 
cylinder head rather than into the carburetor. The four-stroke internal 
combustion engine of FIG. 2 may be of essentially the same type as the 
engine of FIG. 1 and each cylinder may have generally the same basic 
elements shown in FIG. 2 plus a conventional exhaust valve (not shown), in 
the cylinder head 6a. The piston 2 of each cylinder reciprocates in the 
bore 4 of the cylinder wall 5a within the cooling jacket 72 to drive the 
crankshaft which in turn drives the cam 63 and camshaft 64 through timing 
chains (not shown). The cam effects operation of the intake and exhaust 
valves in the usual manner. 
As shown the valve operating means is of a conventional type including 
tappets 65, push rods 66 and rocker arms 67 located under the valve cover 
25a. The end portion of each rocker arm engages the flat end member 68 
carried by the valve stem 69 and moves the intake valve 23a out of contact 
with its seat 22a by compressing the valve spring 71. Opening of the 
intake valve admits the air-fuel mixture form the passage 73 of the intake 
manifold 8a to the combustion chamber 24a where it may be ignited by a 
spark plug 60 at or after the end of the compression stroke. A 
wedge-shaped combustion chamber is shown in FIG. 2 but various other 
shapes can be employed. 
In accordance with the invention, the hydrogen peroxide from conduit 79 is 
injected from a suitable distributor through injector member 20a into the 
air-fuel mixture entering the combustion chamber in timed relation with 
the crankshaft as described in more detail hereinafter. Said injector 
member may be located to inject directly into its associated cylinder or 
to inject into the cylinder head and may be located in the cylinder head. 
As shown it is spaced from the intake valve 23a and has a curved discharge 
tube 74 which directs the liquid toward the valve stem 69. 
As shown in FIG. 2, the electrodes of the spark plug 60 are located at the 
bottom face of the head 6a and at a point farthest from the piston 2 so 
that ignition starts at the uppermost portion of the combustion chamber. 
Optionally, oxygen or an oxygen-rich gas can be injected adjacent the 
spark plug electrodes during the last part of the compression stroke to 
facilitate ignition of a lean mixture. The optional injection nozzle 120 
may be positioned adjacent the spark plug 60 of each cylinder to admit 
metered amounts of pure oxygen to the combustion chamber 24a from a supply 
conduit 121 connected to a source of oxygen, such as the oxygen tanks 35. 
The process is described in more detail hereinafter. 
The present invention involves a process for operating engines of various 
types and is particularly well suited for four-stroke internal combustion 
engines of the type used in "Honda" automobiles having an auxiliary 
combustion chamber for effecting "torch ignition". An engine of this type 
is shown and described in U.S. Pat. No. 3,832,984 and is illustrated in 
FIG. 3 hereof. Similar engines with auxiliary combustion chambers having a 
common assignee (Honda) are disclosed in U.S. Pat. Nos. 3,830,205; 
3,830,206; 3,853,097; 3,837,322; 3,852,379; and 3,844,259; and it will be 
understood that the various cam mechanisms, carburetors, and fuel feeding 
mechanisms disclosed in these patents or used in modern Honda automobiles 
may be incorporated in an engine which is used to practice the present 
invention as will be apparent from the description of this invention. 
FIG. 3, which is employed for purposes of example, shows a Honda-type 
four-stroke internal combustion engine having a series of pistons 82 
mounted in the cylinders 83 of a water-cooled engine block 84. The basic 
engine may have 4 to 8 cylinders, for example, and may be of conventional 
construction. Each cylinder of the cylinder head 86 has a main combustion 
chamber 85 and has a small auxiliary combustion chamber 87 which opens to 
the spark plug 81. A torch nozzle or passage 88 extends between the 
chamber 85 and the chamber 87 to permit the flame to ignite the lean 
mixture in the main combustion chamber. 
Respiration of the Honda-type engine is provided by three valved ports. A 
lean air-fuel mixture is periodically provided to the main combustion 
chamber 85 through a main intake passage 89 of the intake manifold 93. The 
flow through passage 89 is controlled by the main intake valve 90. A rich 
air-fuel mixture is periodically provided to the auxiliary combustion 
chamber 87 through an auxiliary intake passage 91. A small auxiliary 
intake valve 92 controls flow to the chamber 87. A conventional exhaust 
valve (not shown) controls the exhausting of the burned gases from the 
cylinder 83 to the exhaust manifold 94. If desired, heat from the exhaust 
manifold may be employed to preheat the air-fuel mixture from the 
carburetor as disclosed in said U.S. Pat. No. 3,832,984. 
The flame generated in the auxiliary chamber 87 effects ignition of the 
lean mixture in the main combustion chamber 85 and makes possible 
substantial savings in fuel and less air polution. 
In the engine of FIG. 3 a special carburetion system is required to supply 
the lean and rich fuel-air mixtures required for the chambers 85 and 87, 
respectively. As shown most of the air from the air cleaner 77 passes 
through a main dual carburetor 95 having two Venturis 96 and two throttle 
valves 97 controlling flow through the intake passages 98 to the intake 
manifold 93. The carburetor 95 can be adjusted to provide a lean fuel-air 
mixture (for example, an air/fuel ratio in excess of 17:1). 
A minor portion of the intake air passes through a second carburetor 100 
with an intake passage 99 which is small relative to the passage 98. The 
auxiliary carburetor has a small Venturi 101 and a small throttle valve 
102 for controlling flow to the intake passage 91 of the auxiliary intake 
manifold, and the carburetor 100 is adjusted to provide a richer fuel-air 
mixture (for example, an air-fuel ratio less than 16:1). 
The throttle valves 97 and 102 are operated simultaneously and may have 
dual controls or synchronized controls as disclosed, for example, in U.S. 
Pat. No. 3,830,206 or as commonly used in automotive vehicle engines. 
Likewise the intake valves 90 and 92 of each cylinder may be operated in 
the desired sequence using conventional valve-operating mechanisms, such 
as disclosed in U.S. Pat. Nos. 3,830,205 and 3,853,097. 
The engine of FIG. 3 may be a standard type of Honda engine, such as a 
four-stroke four cylinder automobile engine designed to operate with 
standard gasoline; however, the engine is modified in accordance with this 
invention by adding auxiliary means for injecting an oxidizing agent and 
for increasing the amount of oxygen available for combustion and by 
adjusting the carburetor to provide a leaner fuel-air mixture. 
The engine may, for example, be modified by injecting an oxidizing agent, 
such as hydrogen peroxide, into the main combustion chamber 85 or into the 
main carburetor 95. The injection means may, for example, be similar to 
the General Motors fuel injection system illustrated on page 407 of 
"Internal Combustion Engines" (Third Edition) by Edward F. Obert, 
published 1968 by International Textbook Company. In that system a 
distributor or fuel divider (corresponding to the distributor 80 herein) 
supplies fuel periodically to a series of nozzles, each located in an 
inlet port and aimed at an inlet valve. 
As herein shown, a nozzle 200 is located near and above each intake valve 
90 and directs the hydrogen peroxide solution toward the head of the valve 
90 and toward the intake port opening. The hydrogen peroxide and water are 
supplied from a suitable source such as a hydrogen peroxide tank or an 
apparatus as shown in FIG. 1 and the distributor or liquid divider 80 may 
be connected to the discharge end of the conduit 48 or 49 of FIG. 1. 
The distributor 80 may be essentially the same as that employed in the 
General Motors fuel-injection system described above and has a conduit 75 
extending to the nozzle 200 of each cylinder. Eight are provided for a V-8 
engine and four are provided for a four-cylinder Honda engine. The 
distributor is driven by the engine in timed relation thereto and causes 
metered amounts of the liquid to be injected into each cylinder at a 
predetermined time during the intake stroke while the intake port is open 
as shown in FIG. 3, for example during the half of the intake stroke and 
before the valve 90 closes. 
The pressure on the hydrogen peroxide solution supplied to the distributor 
is high enough to provide the desired flow rate through the nozzle 200 and 
may be regulated by a suitable valve, such as the valve 33 of FIG. 1. The 
flow may also be regulated by manifold pressure to reduce flow under low 
load conditions using a diaphragm operated valve, such as the valve 34. 
Optionally pure oxygen or a gas rich in oxygen can be injected into the 
auxiliary carburetor 100 or the auxiliary intake passage 91 to facilitate 
ignition in the auxiliary combustion chamber 87. As shown, an optional 
nozzle 105 is provided below the carburetor 100 to receive oxygen from 
conduit 106 which can be connected to a suitable oxygen source, such as 
the oxygen tanks 35. The oxygen injection makes it possible to obtain 
satisfactory ignition in the chamber 87 with the carburetor 100 adjusted 
to provide a somewhat leaner mixture, and is a possible way to facilitate 
starting or to effect fuel savings. It may also have advantages when using 
special fuel mixtures such as mixtures of alcohol and gasoline. 
It will be understood that the distributor 80 is not needed if the hydrogen 
peroxide solution is introduced into the main carburetor as in the 
embodiment of FIG. 1. 
In carrying out the process of this invention in a standard automobile 
engine, such as illustrated in FIG. 1, it is preferable to adjust the 
carburetor so that the main discharge jet 18 provides a lean mixture and 
so that the idling discharge at 15 provides either a rich mixture or a 
mixture rich enough to permit satisfactory idling of the engine, for 
example at speeds of 400 to 800 revolutions per minute. For example, the 
air-fuel ratio during idling may be less than 15 to 1. 
By injecting an oxidizing agent and water into the carburetor it becomes 
possible to obtain satisfactory operation of the engine with a carburetor 
setting which would otherwise be unsatisfactory because of ignition 
problems or engine knocking with the particular fuel being used. Use of an 
oxidizing agent, such as hydrogen peroxide, makes it possible to reduce 
fuel cost and to reduce air pollution by using a leaner mixture with an 
engine of a given compression ratio, a more economical fuel mixture, 
and/or a higher compression ratio. 
For example, in accordance with one embodiment of the invention, an engine 
with a compression ratio from 9:1 to 10:1 has the carburetor 10 adjusted 
to provide a lean mixture with an air-fuel ratio from about 17:1 to about 
20:1 during operation at normal load. Such an engine may be operated with 
low-lead gasoline having an octane rating somewhat lower than that of the 
more commonly used "regular" gasolines because of the anti-knock 
properties of the water injected with the hydrogen peroxide. 
In the preferred process, the amount of hydrogen peroxide injected into the 
engine is regulated in accordance with engine load and reduced when the 
fuel flow is reduced. This is conveniently accomplished by the apparatus 
of FIG. 1 using manifold pressure to regulate the flow of hydrogen 
peroxide to nozzle 20. The amount of hydrogen peroxide required depends on 
the air-fuel ratio, and for example, is more when that ratio is 20:1 than 
when the ratio is 18:1. In order to employ the maximum air-fuel ratio it 
is desirable to provide a very effective ignition system such as that of 
FIG. 3, but it will be understood that torch ignition is not essential. 
The hydrogen peroxide may be supplied in various ways. Part or all of it 
may be manufactured on the vehicle or part may be provided by containers 
filled with hydrogen peroxide. For example, small tanks may be purchased 
from commercial manufacturers containing 20 to 80 percent hydrogen 
peroxide. 
As shown in FIG. 1, a mixing tank 32 is provided for the hydrogen peroxide 
solution and the solution is maintained under pressure. The hydrogen 
peroxide and water may be supplied to the tank 32 from the supply tank 30 
or any other source. It may be preferred to provide pure oxygen at the top 
of the mixing tank 32 and to maintain the tank under a high pressure so 
that hydrogen peroxide is formed and maintained at the required 
concentration. The high pressure oxygen can react with the water to form 
hydrogen peroxide and its presence reduces the reverse reaction so that 
the hydrogen peroxide has less tendency to decompose during storage in the 
mixing tank. If desired, means may be provided for agitating the liquid in 
the tank 32. 
As shown, the tank 30 is removable, but it will be understood that it may 
have an opening at the top so that the water or a solution of water and 
alcohol or water and hydrogen peroxide may be poured into the tank. 
The oxygen tanks 35 can be at a high pressure, such as 20 to 100 
atmospheres or higher, to facilitate reaction of the oxygen with the water 
in tank 32 and to maintain the desired concentration of hydrogen peroxide. 
In the event the concentration becomes lower than desired because of 
inadequate pressure or for any other reason, additional hydrogen peroxide 
can be introduced from tank 30. If the concentration of hydrogen peroxide 
in tank 30 is high, a separate water tank may be provided to supply water 
for dilution in the mixing tank. 
By providing two oxygen tanks, it is possible to replace either tank at any 
time without loss of oxygen or loss of pressure in tank 32. 
The apparatus for providing hydrogen peroxide to the Honda-type engine of 
FIG. 3 may, of course, be the same as illustrated in FIG. 1. In accordance 
with this invention, the engine of FIG. 3 is operated in such a manner as 
to reduce the amount of fuel supplied to the carburetor 95 and increase 
the air-fuel ratio to a high value, such as 18:1 to 20:1, while 
periodically injecting through the nozzle 200 a hydrogen peroxide solution 
consisting of water and hydrogen peroxide. The solution may contain a 
small amount of alcohol. 
The distributor 80 causes the flow of hydrogen peroxide and water to each 
cylinder to occur only during the intake stroke while the intake valve 90 
is open and cuts off the flow when the valve is closed. The amount of 
hydrogen peroxide injected varies with engine load and may be generally 
proportional to the amount of fuel supplied to carburetor 95. It is 
sufficient to provide the air-fuel mixture in the combustion chamber 85 
with the necessary combustion characteristics. Various means may be 
employed to increase or decrease the rate of flow of the hydrogen peroxide 
solution in accordance with the fuel flow to carburetor 95 or the position 
of the throttle valves 97. This can be conveniently handled by using 
intake manifold pressure to control the flow as disclosed in FIG. 1. 
In the embodiment illustrated in FIG. 3, the hydrogen peroxide must be 
injected before the end of the intake stroke while the intake valve is 
open, but it will be understood that the hydrogen peroxide may be injected 
under high pressure directly into the cylinder while the intake and 
exhaust valves are closed using an injection pump of the type used for 
fuel injection. Direct injection is more complicated than port injection 
but may have some advantages. For example, direct injection of the 
hydrogen peroxide solution during the compression stroke or at the 
beginning of the power stroke may be advantageous. 
The injection of an oxidizing fluid, such as hydrogen peroxide, into the 
main combustion chamber 85 makes it possible to achieve combustion of a 
very lean air-fuel mixture and to employ air-fuel ratios of about 20:1 
because the additional oxygen promotes rapid flame propogation. 
Heretofore it was difficult to ignite a very lean air-fuel mixture, and the 
inert gas, nitrogen, tended to suppress combustion. One way to reduce the 
ratio of nitrogen to oxygen is to add pure oxygen or an oxidizing agent, 
such as hydrogen peroxide. The addition of additional oxygen in this 
manner to increase the ratio of reactive oxygen to fuel substantially 
(e.g., at least 5 to 10 percent) makes it possible to achieve combustion 
with leaner mixtures, to save fuel and to reduce air pollution by 
achieving more complete combustion. 
The process of this invention may, for example, be applied to a standard 
V-8 or 6-cylinder four-stroke automobile engine having a compression ratio 
of around 9.5:1 and designed to operate with the usual "low-lead" or 
"regular" gasoline, such as manufactured by Ford, General Motors or 
Chrysler. The carburetor is adjusted at the main metering jet to increase 
the air-fuel ratio 10 to 15 percent or more to 18:1 or greater and an 
aqueous solution of 20 to 30 percent hydrogen peroxide is fed to the 
carburetor in response to intake manifold pressure (as in FIG. 1) in an 
amount sufficient to provide effective combustion in each cylinder so that 
the engine can perform satisfactorily using a common gasoline such as 
Shell "regular" or Sunoco 190 or a typical low-lead gasoline sold in 
service stations by the major oil companies. 
The process may also be used on a 1976 or 1977 four-cylinder Honda engine 
of the general type represented by FIG. 3 having torch ignition. The main 
carburetor would be adjusted to increase the air-fuel ratio at least 10 
percent over that for which the engine was designed and a hydrogen 
peroxide solution would be introduced into the air-fuel mixture from the 
carburetor as in the previous example in an amount sufficient to provide 
effective combustion in the main combustion chamber of each cylinder when 
common gasolines are used, such as mentioned in the previous example. 
When the Honda engine is so modified, the air-fuel ratio in each auxiliary 
combustion chamber is usually substantially less (e.g., at least 20 
percent less) than that in the main combustion chamber. However, savings 
in fuel can sometimes be effected by increasing the fuel-air ratio in each 
auxiliary combustion chamber, and oxygen can be introduced to that chamber 
from an oxygen tank as disclosed in FIG. 3, for example, to facilitate 
starting or to reduce the probability of poor ignition under difficult 
conditions. 
While some advantages of the present invention are obtained when the 
hydrogen peroxide solution injected into the engine consists of only 10 
percent by weight of hydrogen peroxide, up to 90 percent by weight of 
water, and up to 10 or 20 percent of alcohol, the hydrogen peroxide 
solution usually contains 20 to 40 percent or more of hydrogen peroxide. 
The invention is particularly well suited for modification of an existing 
standard high-compression automobile engine, for example having a 
compression ratio from about 9:1 to about 10:1, because all that is needed 
is simple auxiliary equipment which can be readily mounted on the engine. 
Because the water injected into the engine reduces the tendency for engine 
knock, it becomes possible to employ lead-free gasoline or gasoline having 
a lower octane rating than would otherwise be required. If the water is 
mixed with a fuel, such as methanol or other alcohol, the water injection 
can also provide a lean-burn engine with more power while it is 
accelerating or under high load conditions. 
When modifying an existing standard engine, it is contemplated that the 
carburetor setting would be changed to increase the air fuel ratio 
substantially (e.g., 10 to 20 percent or more) and that the amount of 
hydrogen peroxide solution introduced into the engine would be sufficient 
to promote effectively the combustion of the lean mixture. For example, 
under high load the flow of the hydrogen peroxide solution to the engine 
could be 5 to 10 percent or more of the gasoline flow. The engine may, for 
example, require 1 to 2 gallons or more of the hydrogen peroxide solution 
for each 10 to 20 gallons of gasoline depending on the hydrogen peroxide 
concentration and other factors. 
The process of this invention is versatile and makes it possible to 
regulate a lean-burn engine with simple or computerized controls so that 
it can operate satisfactorily under many different conditions. For 
example, the amount of water and/or alcohol and the amount and 
concentration of the hydrogen peroxide or other oxidizing fluid may be 
varied according to the conditions to obtain optimum performance. The 
auxiliary equipment may also be used for special purposes, such as 
supplying oxygen or hydrogen peroxide for starting or heating a cold 
engine, for providing temporary power increases, or for removing carbon 
deposits. 
The present invention also contemplates various alternate procedures, such 
as introduction of the oxidizing fluid or oxidizing agent with the 
gasoline or other fuel entering the engine or the carburetor. In an engine 
wherein the fuel is injected directly into each cylinder, the hydrogen 
peroxide or other oxidizing fluid can be injected with or mixed with such 
fuel. If fuel is injected into a small auxiliary combustion chamber of 
each cylinder as disclosed, for example, in U.S. Pat. No. 4,038,952, an 
optional procedure is to introduce hydrogen peroxide into each auxiliary 
combustion chamber with the fuel to promote ignition during starting or 
during normal operation and/or to permit increase in the air-fuel ratio in 
the auxiliary combustion chamber or in the main combustion chamber. 
The invention may be applied to various types of lean-burn engines 
including those having recirculation of engine exhaust as in U.S. Pat. No. 
4,041,916 or other special features, such as disclosed in U.S. Pat. Nos. 
4,023,543; 4,040,393 or 4,041,923. The lean-burn engines may employ 
various means to promote ignition other than auxiliary combustion 
chambers, for example as disclosed in U.S. Pat. No. 4,041,922. 
As used herein, the term "oxidizing fluid" or "oxidizing agent" excludes 
air or a gas containing major amounts of nitrogen. 
The term air-fuel ratio means the ratio of the rate of flow by weight of 
air to the rate of flow of fuel and as used herein excludes oxygen 
provided to the cylinder from the hydrogen peroxide solution. 
It will be understood that all percentages given herein are by weight 
unless the context shows otherwise. 
It will be understood that, in accordance with the patent laws, variations 
and modifications of the specific methods and devices disclosed herein may 
be made without departing from the spirit of the invention.