Nitrous oxide plate system

Apparatus for supplying a mixture of oxidizer and fuel to an internal-combustion engine includes a frame supporting oxidizer supply lines and fuel supply lines, the frame being mounted above an intake manifold and below the engine's carburetor. Discharge ports in the oxidizer and fuel supply lines are positioned so that a high-velocity flow of oxidizer entrains and atomizes a stream of fuel from an adjacent fuel-discharge port; each oxidizer port is aimed toward the mouth of a passage in the intake manifold so the stream of mixed oxidizer and fuel is directed into the passage without reducing the level of vacuum in the intake manifold plenum and so that the stream of oxidizer and fuel urges increased amounts of fuel-air mixture from the carburetor into the passage.

CROSS REFERENCE TO RELATED APPLICATIONS 
None. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to devices for introducing an oxidizer such as 
nitrous oxide into the intake manifold of an internal combustion engine, 
and specifically to such devices having perforated supply tubes for fuel 
and oxidizer. 
2. Description of the Related Art 
Introducing an oxidizer into an internal combustion engine to increase 
horsepower is well known. An oxidizer such as nitrous oxide (N.sub.2 O) 
may be injected into passages in an intake manifold which supply air and 
fuel to individual cylinders, or into the primary air-fuel flow into the 
manifold. The latter method typically involves an oxidizer supply having 
tubes extending across the passage joining the carburetor to the intake 
manifold. These oxidizer tubes spray oxidizer into the intake manifold 
plenum from a multiplicity of emitter port; some tube have contained as 
many as 88 ports. 
A major problem with the system just described is that blowing an oxidizer 
and additional fuel into the plenum between carburetor and manifold alters 
and disrupts the "booster signal." Booster signal is used herein to mean 
the reduced pressure, expressed as a level of vacuum, in the carburetor 
throat and in the intake manifold plenum. As engine RPM increases, the 
pistons act as an air pump to pull increasing amounts of air into the 
engine; the partial vacuum in the fuel-air passage between the carburetor 
and the intake manifold becomes stronger with increasing RPM. Booster 
tubes are conduits which connect a fuel supply, typically the carburetor 
float bowl, with the air flow through the carburetor throat. Reduced 
pressure in the throat causes additional fuel to be drawn through the 
booster tubes from the float bowl and fed into the air flowing through the 
carburetor. The effect, of course, is to enrich the fuel-air mixture being 
fed into the intake manifold. 
Blowing high-pressure oxidizer into the plenum below the carburetor raises 
the pressure there so the booster system cannot work as designed. The 
result is a leaning of the fuel-air mixture; the leaner mix can explode in 
the plenum of the intake manifold, damaging the engine. Even if there is 
no explosion, less fuel is fed into the intake manifold and the engine's 
available horsepower is reduced. Winning races depends on getting the 
maximum power possible from an engine, so anything which alters or 
disrupts the fuel supply is unacceptable. 
SUMMARY OF THE INVENTION 
The novelty in the present invention is the type and placement of emitter 
ports on the oxidizer supply tubes, and the consequent lack of disruption 
of the booster signal. Nitrous oxide emitter ports are each aimed at a 
mouth of a runner (passage) in the intake manifold, so the stream of 
oxidizer and fuel flows directly into the runner. This configuration 
avoids the oxidizer being dispensed haphazardly into the intake manifold 
plenum, which raises pressure in the plenum and decreases the quality of 
the vacuum. Lessening the vacuum, as explained above, reduces the amount 
of fuel supplied by the booster system. 
Each fuel port is positioned so that fuel exiting the port will be 
entrained within and atomized by oxidizer flowing from an adjacent 
oxidizer port. Chamfering the mouth of each port allows the oxidizer 
stream to spread and more effectively mix with fuel and air in the intake 
manifold plenum. 
Based on the above, an object of this invention is to provide an apparatus 
for supplying a mixture of fuel and oxidizer to an engine without 
affecting the booster signal of the engine. 
A further object is to provide an oxidizer plate for an engine which will 
increase the horsepower of the engine while allowing additional fuel to be 
drawn from the engine's carburetor. 
Another object is to provide an oxidizer system which blows a stream of 
oxidizer and fuel directly into the mouth of an intake manifold passage. 
Further objects are to achieve the above with devices that are sturdy, 
compact, durable, lightweight, simple, safe, efficient, and reliable, yet 
easy to install, operate, and maintain.

CATALOG OF THE ELEMENTS 
To aid in the correlation of the elements of the invention to the exemplary 
drawings, the following catalog of the elements is provided: 
10 plate or frame 
12 fuel supply tube 
14 oxidizer supply tube 
16 oxidizer valve 
17 fuel valve 
18 oxidizer port 
20 fuel port 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1, a massive frame 10 supports supply lines for fuel and 
oxidizer. "Plate" is used in the industry to refer to the entire apparatus 
of FIG. 1 which is installed on an intake manifold, and is so used herein. 
The plate is installed on an internal combustion engine between the 
primary fuel-air supply (typically a carburetor) and the intake manifold. 
When the plate is installed, a large orifice or opening in the frame 10 is 
a continuation of the passage for the mixture of air and fuel vapor 
flowing from the carburetor into the intake manifold. The plate, made from 
aluminum, is approximately square in plan view, with outside dimensions of 
about 6.25". In one embodiment the orifice, also generally square, is 
5.05" wide, resulting in a plate wall width of about 0.6". These 
dimensions are exemplary, as the dimensions of the plate vary with 
different engines. A thickness of the plate (top to bottom) is about 
1.25". Corners of the plate are drilled to receive mounting bolts. 
Referring to FIG. 2, fuel supply tubes 12 and oxidizer supply tubes 14 
introduce fuel and oxidizer into the fuel-air mixture flowing through the 
orifice in the plate. In FIGS. 1-4 and FIG. 8, the fuel-air mixture flows 
through the plate from top to bottom. Extending from either side of the 
plate, a supply tube passes completely through the frame wall on one side 
of the plate; the closed end of each tube extends into a recess in the 
opposite frame wall and is supported thereby. 
Solenoid valves 16 and 17 control the flow of oxidizer and fuel, 
respectively, into the discharge portion of the tubes, i.e., that portion 
between the walls of the plate--see FIG. 2. Each solenoid valve is 
operated by a pair of electrical leads (not shown). The discharge portion 
of the supply tubes are commonly referred to in the industry as "fuel 
bars" or "rails." 
Thus far, the apparatus as described is well known to manufacturers and 
users of high-performance automobiles and motorcycles. 
As described in a previous section, the most widely used type of carburetor 
has "boosters" for supplying additional fuel to the air stream flowing 
through the carburetor. The booster includes a conduit from the carburetor 
float bowl, which is a fuel reservoir, to the carburetor throat. 
Increasing RPM on the engine increases the vacuum, i.e., lowers the 
pressure, in the carburetor throat; the stronger vacuum causes fuel to 
siphon through the booster conduit. Discharged into the air flow through 
the carburetor throat, fuel from the booster increases the amount of fuel 
supplied to the engine as it revs up to full power. Because the fuel bars 
discharge high-pressure oxidizer and fuel into the area beneath the 
carburetor throat, the effect is to lessen the vacuum in the carburetor 
throat, causing less fuel to be discharged from the booster supply. Thus 
the effectiveness of the booster system is reduced significantly. 
As described below, placement of the emitter ports on the oxidizer and fuel 
supply tubes, and their relationship to each other is critical to the 
function of the present invention. Oxidizer, typically nitrous oxide 
(N.sub.2 O) is supplied under high pressure from a tank on the vehicle. 
Pressure for the N.sub.2 O is in the range of 900-1,050 psi. 
Referring now to FIG. 5, a cross section along view 1--1 of FIG. 3 is 
shown. Similarly, FIGS. 6 and 7 are cross sections on view 2--2 and 3--3, 
respectively, of FIG. 4. The emitter ports for the oxidizer are placed and 
oriented so that the high-velocity flow of oxidizer from each port is 
directed towards the mouth of an intake passage or "runner" on the intake 
manifold. Fuel emitter ports are positioned so that a fuel stream from a 
port intersects an oxidizer stream from the adjacent oxidizer port. The 
arrows on FIG. 5 are to indicate the direction of oxidizer and fuel 
streams. Fuel spraying from a fuel port adjacent an oxidizer port is 
pulled into the oxidizer stream, where the fuel is immediately atomized. 
Referring still to FIG. 5, the relationship of a fuel port 20 to an 
oxidizer port 18 is shown. The fuel port emits fuel generally 
horizontally, while the oxidizer port is oriented toward the mouth of a 
runner in the intake manifold. A detail of an oxidizer port 18 is shown in 
FIG. 6, and a detail of a fuel port 20 is shown in FIG. 7. For 
installation on an eight-cylinder engine, each of the two fuel bars or 
tubes 12 has four emitter ports 20, one for each runner on the intake 
manifold. Similarly, each of the oxidizer tubes 14 has four ports, each 
paired with an adjacent port on the nearby fuel bar. 
As one example, many intake manifolds are in a "square" configuration, 
having two passage entries or mouths on each of four sides of the intake 
plenum. To accommodate this configuration the nitrous plate has two pairs 
of supply lines, one on either side of the orifice in the plate. Each 
supply tube has four emitter ports, with the ports nearest the center of 
the tube directed towards intake passages on one side of the manifold. 
Ports nearest each end of the tubes supply intake passages on the front 
and back walls (relative to the vehicle) of the manifold. 
A typical diameter for an oxidizer port is 0.043", and for a fuel port is 
0.031". These dimensions may vary, and would be larger for engines of 
greater horsepower. An outer end of each port is chamfered so the mouth of 
each port is wider than its throat. The flow through a port begins to 
expand while still in the chamfered section of the port, and the expansion 
continues as the stream exits the mouth of the port. Especially in the 
case of the high-pressure oxidizer, the stream broadens into wider flow on 
exiting the discharge port. Because the oxidizer stream is moving at a 
high velocity, a zone of reduced pressure is created around the flow; this 
reduced pressure causes the nearby fuel stream to be pulled into the 
oxidizer stream. The oxidizer flow entrains and atomizes the fuel, so that 
oxidizer and fuel are well mixed as they enter the mouth of a passage en 
route to a cylinder. 
Flowing towards and into a runner mouth, each oxidizer-fuel stream 
increases the velocity of the air-fuel mixture moving into the runner 
mouth after having passed through the carburetor. Consequently, the 
overall flow of air through the carburetor increases when the oxidizer 
system is in operation, and the level of vacuum in the carburetor throat 
increases. Because the introduction of extra fuel from the booster outlets 
is responsive to the vacuum in the carburetor throat, additional fuel is 
drawn from the booster outlets, enriching the fuel-air mix. Engine 
performance is therefore enhanced not only by the introduction of an 
oxidizer, but also by the increased flow of fuel from the carburetor. 
The restrictive description and drawing of the specific examples above do 
not point out what an infringement of this patent would be, but are to 
enable one skilled in the art to make and use the invention. Various 
modifications can be made in the construction, material, arrangement, and 
operation, and still be within the scope of our invention. The limits of 
the invention and the bounds of the patent protection are measured by and 
defined in the following claims.