# The Webster-Heise Valve: A Significant Improvement in the Internal Combustion Engine and Its Fuels?

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## Record

- **Collection:** Congressional research report
- **Document type:** CRS Report
- **Published:** September 7, 1982
- **Citation:** 82-176ENR

## Text

Report No. 82-176

ENR

LIBRARY
THE WEBSTER-HEISE VALVE :
A SIGNIFICAYT IA'ROVEA'A'NT
IN THE INTERNAL
COMBUSTION ENGINE AND ITS FUELS?

David M. Lindahl
Analyst in Energy Policy
Environment and Natural Resources Policy Division

COMPLIMENTS O F

Gene Snyder

September 7, 1982

GOVERNMENT DOCUMENTS
COLLECT1ON

T h e Congressional Research Service tvorks exclusively for
the Congress, conducting research, analyzing legislation. and
providing information at the request of committees. XIemhers, and their staffc.
T h e Service makes such research available, without partisan bias, in many fi~rrnsincluding studies. reports, compilations, digests, and backqround briefings. Cpon request, CRS
assists committees in 'analyzing legislative proposals and
issues, and in assessing the possible effects of these proposals
and their alternatives. T h e Service's senior specialists and
subject analysts are also available for personal consultations
in their respective fields of expertise.

ABSTRACT
The efficiency of internal combustion engines has long been limited
by the problems associated with fuel preparation and distribution.

A new

valve technology has been developed which may reduce or eliminate some of
those problems.

The Webster-Heise valve apparently causes gasoline and

other auto fuels to vaporize at low engine temperatures and to mix with
incoming air.

Preliminary testing suggests potential for major oil conser-

vation, increases in available torque, improvements in fuel economy, and
major reductions in lead and other additives and in automotive pollutants
such as nitrogen oxides, carbon monoxide, and unburned hydrocarbons.

The

valve also appears to reduce engine octane requirements by 10 to 15 points.
Additional testing will be necessary to fully evaluate its potential.

This report was originally requested by the Senate Committee on Environment
and Public Works and is reproduced for general distri.butionwith the
Committee's permission.

ACKNOWLEDGEMENTS

H e l p f u l r e v i e w s and s u g g e s t i o n s were provided by
David Gushee, Robert Trumbule, J o s e p h B i n i e k , C a r l Behrens,
R o b e r t Bamberger, Maria Grimes, George Chatham, and James
Robinson,

F l e a d a S c o t t typed t h e m a n u s c r i p t and p r o v i d e d

editorial assistance.

The c o o p e r a t i o n of t h e E t h y l Cor-

p o r a t i o n , t h e Environmental T e s t i n g C o r p o r a t i o n , t h e Ford
Motor Company, G u l f Research and Development C o r p o r a t i o n ,
MacMillan P r e s s , Goodheart-Willcox Company, and t h e
Webster-Heise C o r p o r a t i o n i n t h e p r e p a r a t i o n of t h i s r e p o r t

is greatly appreciated.

CRS-vii
CONTENTS
Page

. Preface .................................................... 1
11. Executive Summary .........................................
3
I11. Introduction ..............................................
9
IV . Physical Description ....................................... 1 5
V.
History .................................................... 2 1
VI . Status and Outlook ......................................... 29
VII . Potential Benefits ......................................... 3 4
A . Refinery Feedstock Conservation ........................ 3 4
B . End-Use Fuel Conservation .............................. 37
C . Air Quality ............................................ 39
D . Competitiveness of the Auto Industry ................... 43
VIII . Is There a Federal Role? ................................... 47
APPENDIX I . Technical Analysis .................................
50
A.
Pre-Combustion Effects ..................................... 5 1
1. Gasoline Vaporization .................................. 5 1
2 . Mixing ................................................. 7 3
3 . Distribution ........................................... 7 6
4 . Volumetric Efficiency .................................. 8 3
B.
Combustion Effects ......................................... 86
1. Combustion Stoichiometry ............................... 8 6
2 . Octane Requirements .................................... 88
3 . Torque ................................................. 1 0 0
4 . Cycle-By-Cycle Combustion Variations ................... 1 0 4
5 . Fuel Economy ........................................... 1 0 6
I

CRS-viii
CONTENTS (CONTINUED)

Page

.

....................................
1. Emissions ..............................................
2 . Driveability ...........................................
3 . Engine Maintenance .....................................
4 . Catalytic Converter Operation ..........................
APPENDIX 11 . Summary of Tests ...................................
C

Post-Combustion Effects

115
115
122
124

126
127

I.

PREFACE
This report is an analysis of the concept, technology, and hardware

of a new valve to increase engine efficiency that has been developed
by the Webster-Heise Corporation.

The methodology used in this report

consists of a discussion of the attempts to improve internal combustion,
a physical description of the Webster-Heise valve and its operation,
a history of the development of the valve, the current status of the
device, the outlook for its possible acceptance, and its potential impact
on various issues of national concern.

The Appendix consists of a more

detailed analysis of the nature of the existing problems in current
production systems, the theoretical reasons for these problems, and
their theoretical solutions as related to the Webster-Heise valve.
In addition, a summary of tests is provided so that the reader will
have relevant data on which to base his own conclusions. The technical
analysis (Appendix I) is a system approach (from carburetor to tailpipe)
explaining the effects of the valve upon different aspects of combustion
(before, during, and after).

To the extent that a phenomenon (such

as differential vaporization) is repeated in analyzing these effects,
any such repetition should be considered to be supplemental rather than
additive

.

This report should not be considered to be a recommendation for or
against the Webster-Heise valve or the related technology.

There is

not yet enough evidence to support such a judgment either way.

The

data that is available, however, suggests that a closer investigation of

it by the auto industry and by the Federal Government would not be
inappropriate.

If its potential for greater fuel conservation, reduced

emissions, and lower octane requirements can be even partially realized,
the introduction of the Webster-Heise valve could be a very significant
development.

11.

EXECUTIVE SUMMARY
From the inception of the gasoline-powered spark-ignition engine,

there have been numerous attempts to improve the condition of the charge
reaching the cylinders.

The carburetor allows the proper amount of

gasoline and air into the engine but, because much of the fuel is in
the form of liquid droplets (which will not burn in that form), combustion cannot occur at maximum efficiency.

This causes undesirable effects

such as "engine knock", imperfect fuel distribution to the cylinders,
cycle-by-cycle variations, dieseling, engine deposits, less than optimum
conversion of heat to work, increased engine wear, increased fuel consumption, loss of power, some driveability problems, and increased pollutant
emissions.
The auto industry has attempted to solve the problem of inadequate
vaporization by increasing the temperature in the intake manifold to
heat the incoming air and fuel.

This increases the rate of vaporization,

but the high temperature in the manifold greatly reduces the density
of the air that is admitted to the cylinders.

This provides less air

for combustion and expansion in the cylinders, resulting in reduced
power.

To deal with the problem of "knock", tetraethyl lead or other

additives are used to slow down the rate of combustion.

They allow

the engine to operate but introduce additional losses of thermal efficiency.

The slower burn also gives nitrogen oxides ( N O x ) , a principal

contributor to smog and acid rain, a greater opportunity to form.

Tetra-

ethyl lead has been associated with health effects, particularly on
children, and is currently being phased out of gasoline as a result.

Both of these pollutants are currently the subjects of debate in the
Congress.
The Webster-Heise valve was developed to deal specifically with
the combustion problems caused by incomplete vaporization.

It is not

a carburetor but is a valve that fits below the carburetor and extends
into the intake manifold.

According to the Webster-Heise Corporation,

it causes more of the gasoline in the airlfuel mixture to vaporize at
any given manifold temperature and provides complete vaporization at
intake manifold temperatures as low as 125 degrees F.

This claimed

achievement is made possible, according to the company, by a transverse
shearing of droplets in the gasoline spray by highly turbulent air
followed by passage through an area of lower pressure.

These effects

are produced by a matrix of thousands of small nozzles formed by
two stainless steel concentric screens of different mesh size through
which both gasoline droplets and air pass before reaching the intake
manifold.
The turbulence and friction created by the passage of the air
through the screens transfer enough energy to the gasoline to cause
it to vaporize when it enters the lower pressure area of the intake
manifold, according to Webster-Heise.

It is further claimed that, be-

cause of early gasoline droplet vaporization, the vaporized gasoline
has time to mix uniformly with air prior to entering the intake valve
of each cylinder.

This pre-vaporized and then thoroughly pre-mixed

fuel charge permits equal distribution to, and within, each cylinder,
thereby satisfying the conditions required for efficient combustion.
At temperatures lower than 125 degrees F, even though the gasoline
may not be fully vaporized, some efficiency gains are realized

apparently due to the small droplet diameters resulting from the finer
atomization and to improved mixing.
The effects of the Webster-Heise valve on combustion are very important, according to its designers.

The vaporization of the gasoline pre-

vents its collection as liquid on the metal surfaces of the cylinders
and pistons.

This also prevents dilution of the crankcase oil and promotes

more complete combustion because the oxygen in the air has greater access
to the hydrocarbon molecules and can oxidize them more completely.
deposits are less likely to form as a result.

Carbon

Vaporization also reduces

the occurrence of fuel-rich pockets in the extremities of the cylinders
where detonation would otherwise take place.

Catalysts such as lead,

which slow down the reaction rate, do not appear to be needed because
the conditions causing "knock" are not present to the same degree.

This

allows the combustion to occur more quickly, meaning that lower-octane
fuels can be used without "knock", that more pressure can be exerted
on the crank at the optimum moment, that NOx has less time to form,
and that less heat can be transferred to the engine walls.
The Webster-Heise valve has been formally tested six times at EPArecognized laboratories on all of the-EPAvehicle tests on a wide range
of octanes (97 to 75) and in the test laboratories of automobile and
octane additive manufacturers.

The test results vary to some extent

with the type of test and the conditions under which they were run,
but data (see Summary of Tests) comparing the Webster-Heise modified
car with a baseline car (including the same car without the valve) show
the following representative results:

Fuel economy increased from 6 to 20 percent;
Torque (power) at 1500 RPM increased from 13
to 40 percent;
NOx emissions declined from 4 to 48 percent;
Carbon monoxide (CO) emissions declined from 17
to 54 percent;
Hydrocarbon (HC) emissions declined from 5 to 13
percent;
Engine octane requirements declined by 10 to
15 points.
Tests to date indicate that the Webster-Heise valve enables
an engine to operate on much lower octane than is possible in the
unmodified engine.

Because the charge is less likely to "knock" because

of its conditioning by the valve, gasoline of lower octane (which burns
faster than high octane) can be used effectively.

In the Webster-Heise

modification, gasoline with an octane rating of 75, blended and
certified by the Phillips Petroleum Company, outperformed in all categories
the 97-octane fuel used in the baseline car in comparative tests.
More work needs to be done to determine whether or not the test
results obtained so far can be translated into commercial products with
wide utility. However, the potential of a technological breakthrough
of this magnitude provides a significant incentive for continued effort.
If the valve were in use in all of the automobiles in the United States
and if the fleet obtained the same results on average that the tests
showed, the refining industry could save about 600,000 barrels per day
(b/d) in crude oil by avoiding the extra processing now necessary
to boost the octane of gasoline.

It could also take much of the

pressure off petrochemicals such as aromatics, which have other

noncombustion uses.

In addition to the 600,000 b/d that could be saved

at the refineries, the gasoline conservation that could be realized
by consumers through better fuel economy could be on the order of 650,000
to 1,300,000 b/d (somewhat more than the U.S. imports of crude oil from
Saudi Arabia).

The market for lower-octane gasolines would provide in-

dependent refiners with an opportunity to avoid the expensive investment
in reforming equipment now needed to compete with the major oil companies
It would also greatly

in the manufacture of premium unleaded gasoline.

reduce the pressure to increase allowable lead levels in gasoline and
could accelerate the phaseout of tetraethyl lead as a gasoline additive
(assuming appropriate timing).

The positive health effects of elisinating

lead could be supplemented by positive reductions in uncontrolled NOx,
CO, and HC emissions and thus in control costs.

The lower cost (about

20 cents per gallon less) of straight-run gasoline over premium unleaded
could also benefit consumers.
Despite the fact that the production cost of the valve would probably be under $100 each and that it could be easily adapted to most new
car engines, the institutional barriers to the acceptance of a new device can be formidable and preproduction testing may reveal unforeseen problems.

In addition, the skepticism generated by the failures of others,

plus the known costs and reliabilities of the technologies and products
now in use, would have to be overshadowed by the performance and promise
of a new technology and product.

At this time, the auto companies,

the most likely beneficiaries of the Webster-Heise technology, seem
to be, for the most part, unsure of the next step.
been skeptical.

They have so far

This may be due to the fact that it was not invented

in their own research laboratories, and consequently they have no
I.

.

~n-house" experience with it.

The relative advantages from the use

of such a device could change if current trends toward fuel injection
and dieselization continue, because the auto industry has invested large
amounts of capital and effort in them.

On the other hand, the U.S.

auto industry has a desperate need to improve its existing products
without substantial price increases, a need which might accelerate the
rate of testing of the valve and possibly facilitate its subsequent
acceptance.

The disincentives of the cost and time required to evaluate

the valve must be weighed by a company against the incentives of potentially improved performance and greater buyer acceptance of the cars
on which it is used.
More testing of the valve is clearly needed on a wide variety of
vehicles to establish a larger data base before its full potential can
be precisely determined.

This would presumably be the responsibility of

private industry but some have proposed that the Federal Government
might take an active role in evaluating it.

The Government has testing

facilities and vehicle fleets that ate sometimes used for such purposes.
Such testing, however, can be expensive for the Government as well and
the desirability of doing it must be weighed against competing demands
on Government resources.

Because the effects of the valve touch upon

several major issues of concern to the Congress (lead levels in gasoline,
oil conservation, air quality, competitiveness of the auto industry, and
others), this may be an appropriate course of action for consideration
independent of the auto industry response.

111.

INTRODUCTION
The history of the spark-ignition gasoline-powered engine is filled

with attempts to improve it.

Although there have been many modifications

made in engine design over the past century, the fundamental process of
delivering air and gasoline to the engine has not changed much over the
years.

Gasoline is still sprayed by the venturi jet of the carburetor

through a needle valve into the intake manifold as air passes through it.
This causes the gasoline to atomize into droplets which may be further
reduced in size through secondary atomization when they strike the
throttle plate (when it obstructs the flow at low engine speeds). This
atomization increases the surface area of the droplets and increases the
amount of vaporization that can occur.

Because of the extremely short

time available for vaporization to occur in the manifold, however, this
is not generally sufficient to fully vaporize all of the gasoline.

The

presence of the liquid gasoline (rather than gasoline vapor) in the
cylinders contributes to a variety of mixing, distribution, combustion,
and lubrication problems.

The carburetor, therefore, does an excellent

job of metering out precise amounts of gasoline and air to maintain
the proper air/fuel ratio but, except for breaking the liquid gasoline
into small droplets which results in some vaporization, it does not
completely overcome the phase problem.

In order to increase the rate

of vaporization, most auto manufacturers use high temperature (in the
form of a hot spot on the bottom of the manifold or a heated water jacket
around the manifold) to force more of the gasoline into a vaporized state.
These elevated temperatures, however, reduced the density of the air
reaching the cylinders, resulting in less power output from the engine.

Baffles are often used to promote mixing of the air and gasoline but these
tend to restrict the flow and provide surfaces on which the gasoline can
impinge and recondense.
Dozens of inventors, both individually and as employees of large
corporations, have attempted to solve this phase problem but have been
ultimately unsuccessful.

These devices failed because of several common

characteristics:
They were not variable but were optimized for only
one steady-state condition (a fixed screen, for
example). As a result, any change from the optimum
engine speed would mean reduced performance which
on the average was almost always worse than that for
the unmodified engine.
They constituted restrictions because they reduced
the space open to the passage of air and fuel, especially at high engine speeds, and consequently reduced the power the engine was able to produce.
Their gains were .offset by losses (usually power
or emissions) that made the devices impractical.
They attempted to modify carburetion in some way.
Even though the carburetor is a very efficient
metering device, it atomizes the gasoline but does
not fully vaporize it.
They attempted to improve the vaporization rate
of gasoline in an area above the throttle plate.
As soon as the improved mixture, if any, impinged
on the throttle plate it would reformulate droplets and destroy the gain.
They did not work (for some combination of the
above reasons).
Some of these devices, such as the Pogue carburetor and its
variations (which was marketed but turned out to be unsatisfactory because it was difficult to keep in proper adjustment), have been
the subject of extreme claims.

Because of the intense concern over

fuel economy in the wake of serious international oil emergencies, the
interest of the public, the auto industry, and the Federal Government
has been raised and eventually dashed by these well-intentioned inventors who proved not to have the answer they sought.

It should be noted

that this applies to large corporations, including the auto companies,
as well as to individuals.

Some improvements in carburetion have been

realized, but the fundamental phase problem still remains.

Very little

work, however, was done on charge conditioning below the carburetor.
As a result of this succession of technological disappointments,
Americans have become highly skeptical of any new device that promises to improve combustion. This makes it more difficult than ever
for a new idea to succeed.

To do so, it must overcome the inertia of

justified doubt generated over the last 50 years and especially over
the last 10.
Sherwood F. Webster and Richard L. Heise claim to have discovered
a means of vaporizing gasoline rapidly at low temperature. Their valve
is a significantly different approach from the many devices which have
preceded it.

They have demonstrated in six formal tests and numerous

informal ones that this has the effect of improving fuel economy, improving torque, reducing harmful exhaust emissions, improving driveability,
and reducing the octane requirements of the engine on which it is used.
Considerably more testing is needed, however.
Although some earlier devices employed a screen, it was a single
screen that was fixed horizontally in the path of the air/fuel mixture.
The Webster-Heise valve uses two screens, which have specific shapes,
sizes, and proximity to each other that are critical to the process of

early vaporization (see Physical Description).

The valve conditions

the 2asoline and air so that each cylinder receives a charge that can
burn more efficiently.
It is not unusual for major innovations to come from outside the
auto industry.

As Gushee et al. point out:

-1/

The tendency of innovations is to emerge
from outside the industry. Several recent
studies have shown this happening at a three
to one ratio. The reason for this is that external industries do not have the commitment to
the existing technology and do not have to worry
about losing their existing market.
Typically, an innovation is introduced on a
a small scale, tested, and proved; gradually it
penetrates the market. The period of experimentation varies widely depending on numerous
factors, and involving the complexity of the
innovation, the extent of the supporting system
for the existing technology, and the social
values affected. Several years is almost certainly the shortest period in which a major
innovation can fill a market opportunity.
In the auto industry, technological
change seems to take a long time-at least
it seems like a long time while one is in the
period of change. Today's spark ignition
engine produces about 10 times the horsepower per pound of engine that Henry Ford's
best efforts could produce in 1900, but all
seven decades have been needed for this progress to occur. In the area of technological
substitution, these time lags are also apparent.
It took 20 years for power brakes to be installed
on half the new cars, 15 years for air conditioning on half the new cars, 10 years for power
steering on half the new cars.

11 David E. Gushee, Joseph P. Biniek, John E. Blodgett, and Mauree

ton-(congressional Research Service).

History and Future of Spark
Ignition Engines. Committee Print prepared for the Senate Committee
on Public Works, Serial 93-10, U.S. Govt. Printing Off.: Washington,
D.C. September 1973. p. 3-21.

In a recent study on the competitive status of the U.S. auto
industry, the National Research Council and the National Academy of
Engineering concluded the following:

-21

The clear competitive advantage accruing
to products with advanced efficiency performance has created an incentive for the development of improved hardware. If the real price
of oil continues to rise and we experience
significant supply interruptions, the future
course of product innovation may become more
radical...
We are concerned with the general pace
of innovation as well as its general
character. Two aspects are especially critical. The first is the diversity of technology growing out of the innovative process;
the issue is essentially whether, for any
given system, a new dominant design is apparent. The second aspect is the extent to
which innovation departs from design concepts
currently in use, whether innovation is
epochal or incremental...
The evidence suggests that innovation
in the 1970s generally has proceeded first
where the cost of change (in terms of its
impact on the existing process) has been
least. This serves to underscore the potential for change in future years. The
technologies involve not only new design
concepts but also in many cases totally
new physical or mechanical and chemical
principles. And indications are that such
developments are not the flight of some
engineer's fancy; extensive development
work is under way in all areas and is
some cases has been speeded up remarkably
in the last two years...
In terms of product technology, a
period of intense technological competition may be just ahead.
2 1 National Research Council and the National Academy of Engineering.
The competitive Status of the U.S. Auto Industry: A Study of the Influences
of Technology in Determining International Industrial Competitive Advantage.
National Academy Press: Washington, D.C. 1982. p. 132-157.

The Webster-Heise valve might be considered "incremental" in terms
of its potential impact on the auto industry in that it probably would
not require substantial changes in the existing equipment or production
techniques.

Its impact outside of the industry, however, could be con-

sidered "epochal" in terms of eliminating the need for gasoline additives,
reducing crude oil imports, and improving air quality.

In contrast,

downsizing has been incremental in terms of technology but "epochal"
in that it requires major changes in capital, labor components, management, and organization.

IV.

PHYSICAL DESCRIPTION
The Webster-Heise valve is a relatively simple device, but it has a

highly complex effect on the air and gasoline that pass through it and on
the combustion that results.

Of the 26 claims that were made in the

two patent applications, all 26 were granted by the U.S. Patent Office.
It is covered by two patents each in the United States and in nine foreign
countries (Japan, West Germany, United Kingdom, France, Italy, Sweden,
Canada, Mexico, and Brazil).

3-1 4
1

A related patent covering turbine

and oil-burner applications has also been issued, 51

and one covering

noncombustion applications such as spray drying, fluid-bed operation,

-

and desalination is pending. 61
The valve is mounted at the intake manifold opening below the carburetor and throttle plate and extends down into the intake manifold
(Figs. 1 and 2).

Air and gasoline are received from the carburetor and

are directed through a slight funnel (the central down-tube) to promote
centralized charge mixing.

As needed, additional air can be drawn

down the outer down-tube.

At high speed or load conditions, air only

31 Sherwood F. Webster and Richard L. Heise. "Intake Manifold
~ariazleAtomizing Valve." U.S. Patent No. 4,187,820. February 12,
1980.
41 Sherwood F. Webster and Richard L. Heise. "Variable Capacity
Fuel Delivery System for Engines." U.S. Patent No. 4,285,320. August 25,
1981, p. 1-8.
51 Sherwood F. Webster and Richard L. Heise. "Fuel Delivery System
for ~ Z b u s t i o nDevices. " S.C. /Serial No. 6,263,696. Allowed May 6, 1982.
61 James F. Olmsted, Sherwood F. Webster, and Richard L. Heise.
" ~ h e r ~ o d ~ n a mConditioning
ic
of Air or any Other Gas to Increase the
Operating Efficiency of Diverse Energy Consuming Systems." S.C./~erial
No. 6,398,977. Filed July 16, 1982.

Figure 1. Vertical cross-section of the WebsterHeise valve indicating the range of
movement and the direction of flow in
the intgke manifold.
Source: Webster-Heise Corporation

Figure 2. Cut-away view showing placement of the
Webster-Heise valve in the intake manifold below the carburetor.
Source: Webster-Heise Corporation

is allowed into the outer down-tube (Fig. 3).

At the bottom of the

central down-tube, the gasolinelair mixture changes direction by 90
degrees and is directed toward the double-screen assembly that surrounds
the valve (Fig. 4).

The bottom of the valve is solid and slightly con-

cave to aid in the redirection of the mixture.

"

Because the flow

from the central tube must cross the radial jump space between the
central tube and the screens, it accelerates after changing direction
and strikes the screens with force.

The screens consist of a cylindrical

850 stainless steel mesh (coarse) immediately followed by a #I20 stainless

steel mesh (fine).

The mesh sizes are critical and so is their proximity;

they must be in contact to maintain the appropriate level of turbulence
and to form the matrix of thousands of orifices that the gasoline and
air must pass through.

The air forces the gasoline through the orifices

to produce droplets of extremely small diameters.

Because of the lower

pressure in the intake manifold, the high level of turbulence, and the
higher energy level of the air, vaporization of the gasoline is believed
to occur within a short distance after leaving the outer screen.

Because

moving air is the driving force and because turbulence is created by its
passage through the valve, the gasoline vapor and air are thoroughly
mixed.

The radial structure of the screen assembly directs the gasoline1

air mixture evenly toward the cylinders so that all receive the same
quantity and quality of charge.
The valve is automatically regulated by engine demand.

A one-

inch vacuum differential between the interior and exterior of the
valve is maintained by a vacuum regulator which senses the pressure
at a point above the valve (but below the carburetor throttle plate)

Figure 3. Vertical cross-section showing the
central and outer down-tubes (note
direction of flow).
Source: ~ebster-Heise Corporation

Figure 4. Cross-section (horizontal) indicating
the position of the central and outer
down-tubes relative to the double-screen
assembly and the radial jump-space (note
direction of flow).
Source: Webster-Heise Corporation

and sat a point below the valve in the intake manifold.

As the acce-

lerator is depressed and more gasoline and air are required, the
manifold vacuum is lowered.

The vacuum regulator senses this pressure

change and relaxes enough to permit the valve to descend further into
the manifold under the greater force of the increased flow of gasoline
and air.

This exposes more of the double screen to accommodate and

to process the greater flow.

Because of this variability, there is

no restriction to the flow except for a one-inch pressure drop (maintained
by a vacuum differential valve) which enhances the vaporization effect
and which constitutes a restriction only at wide-open throttle.

As the

velocity of the flow diminishes with lower engine demand, the vacuum
regulator causes the double-screen assembly to retract to maintain the
one-inch differential under all speed and load conditions.
The "double down-tube" is especially important to the performance
of the valve.

All of the gasoline droplets and most of the air from

the carbiretor are directed toward the center of the top of the valve
where they are collected in a shallow funnel which accelerates them
(through a Bernoulli Effect) through the center tube.

As it exits the

bottom of the tube, the gasoline/air mixture is forced outward in a
radial pattern toward the double-screen assembly that surrounds the
flow.

Before the mixture reaches the screens, it must traverse a "radial

jump space" across the width of the larger, outer tube.

This causes

the mixture to not only change direction by 90 degrees but also to accelerate toward the double screens.

At the same time, air and a very

small amount of gasoline vapor descend under atmospheric pressure through
the outer down-tube.

In addition to providing the radial jump space

that the primary flow must cross, this secondary flow-around the center
tube adds more turbulence when it intercepts the primary flow and greater
volumes of air when needed under high-speed or high-load conditions.

V.

HISTORY
Development of the Webster-Heise valve began in 1978 when

Sherwood F. Webster and Richard L. Heise decided to combine their
knowledge and experience in an attempt to reduce the fuel consumption
and pollution levels of modern internal combustion engines.

I/

Webster had worked in this field since 1959, mainly with variable venturi carburetors and cold manifolds, and Heise was well known in the
Phoenix area as a master mechanic.

At the outset, they decided that

their approach would be to atomize all of the fuel below the throttle
plate rather than to attempt separation of the gasoline into its
"light" and "heavy" components.

They concluded that a cylindrical

valve that could move up and down in the intake manifold in response
to engine demand would be the best way to eliminate the problems
that were known to exist with fixed systems.
The problem confronting them at that point was the need to
find a simple yet satisfactory atomizing mechanism to reduce the
diameters of the gasoline droplets.

Even though both inventors

were familiar with the failure of single horizontal screens in the
past, they decided to experiment with a variety of screens, not knowing
whether any would work in their application or not.

A test apparatus

was constructed consisting of a simple venturi extending above the container of water in which it was immersed and an air compressor which
directed a continuous flow of fast-moving air over the venturi to
simulate the flow of the charge through an automotive carburetor.

7 1 Richard L. Heise and Sherwood F. Webster.
cation to David Lindahl, August 9, 1982.

Personal communi-

Various screen sizes from #50 to I7350 were tried with no success.
The water would merely run in large drops down the side of the screen
onto which the flow was directed.

After two months of screen testing,

it was apparent to both Webster and Heise that a single screen would
not work, as earlier inventors had already shown.

In the process of

changing from one screen size (#50) to another (#120), however, Heise
accidentally held both screens together and noticed to his astonishment
and that of the others present that a totally unexpected phenomenon
was occurring.

The water was no longer falling in large drops on the

impact side of the double-screen combination, but the entire flow was
passing through the screens in a virtually invisible mist.

Only when

a watch crystal was placed in the flow downstream from the screens did
small droplets reform and become visible.
On the basis of that discovery, they added a double screen assembly
to the valve and assumed that they had achieved a major breakthrough
in automotive fuel conditioning. They assembled an early prototype of
the valve and eagerly installed it on a 1972 Chevrolet pickup truck.
They were disappointed to discover that not only was there no apparent
gain, they actually lost fuel economy.

This setback was followed by

a period of trial and error during which numerous modifications were
tried and rejected as ineffective.

After a succession of these failures,

they concluded that the problem was due to the fact that the flow from
the carburetor was not striking the screens with sufficient force because
of the low angle of approach.

To correct this situation, they developed

the double down-tubes, which provided space between the bottom of the
central tube and the double screens to force the flow to strike the

screens directly at right angles rather than at acute ones. 'After further
experimentation, they observed that the maximum effect appeared to occur
when the pressure differential between the interior and the exterior
of the valve was held to a constant one inch.

A vacuum valve was used

to replace the spring which originally controlled the action of the
valve so that more precision could be obtained.

As a result of these

incremental improvements to the basic valve over a six-month period,
the fuel economy of the truck was raised by about 0.5 MPG at a time
from 12.5 MPG to 16.0 MPG with noticeably better performance, according
to Webster and Heise.
As the gains became more apparent so did the need for more sophisticated testing.

Webster and Heise formed a corporation to attract the

capital necessary to complete the development of the valve.

Approximately

$450,000 was raised privately, including $75,000 from Webster.

This

was used to cover the cost of patents, tests, vehicles and equipment
(including a complete dynamometer), professional services, legal fees,
81 Both Webster and Heise have worked exclusively on the deand travel. velopment of the valve since 1978.
In early 1980, after the initial development work was completed,
the inventors asked the Ethyl Corporation to test the device.

Webster

and Heise suspected, but had not yet confirmed, that use of the valve
reduced engine octane requirements. Their presumption was that Ethyl
would be interested in an alternative to chemical octane because of the
lead phasedown in gasoline that was underway as a result of the Clean

81

Sherw0od.F. Webster.

A U ~ U S
10,
~ 1982.

Personal communication to David Lindahl.

Air Act.

Ethyl agreed to test it at its research laboratory near Detroit

(see Test 1, Summary of Tests).

During the test at Ethyl, an octane

requirement reduction of 10 points was established, an improvement in
distribution was verified, and no loss of power was measured (See Test
1, Summary of Tests).

-91 Ethyl wanted to dismantle the engine and the

valve to analyze it further over a one-month period, which was acceptable
to Webster-Heise, but would not agree to cover Webster-Heise's expenses
during the testing period.

As a result, Webster and Heise decided to use

their limited funds for testing at other certified laboratories.
In August, 1980, tests were conducted at the Environmental Testing
Corporation (ETC) near Denver, Colorado (an EPA-recognized test facility).
These tests, as shown in the summary of tests, confirmed earlier, less
complete tests that had shown gains in fuel economy, reduced emissions,
and lower octane requirements. On the basis of those tests, invitations
were sent to all of the major automobile and oil companies to attend
the formal introduction and demonstration of the valve at ETC on October 15, 1980.

Fifteen major corporations sent representatives who

witnessed the operation of the test car and a baseline car (see Test 4,
Summary of Tests).

EPA tests were run on both cars, and three different

fuels were used (97-indolene, 85 pump-grade unleaded, and 75-octane
specially blended and certified by Phillips Petroleum Co.).

The gains

demonstrated in these test were consistent with the earlier tests.

At

the demonstration, John 0. Marsh, Jr., the Webster-Heise corporation counsel (now Secretary of the Army), offered to license the valve to any U.S.
9/ William Adams (Chief Engineer, Ethyl Research Laboratory).
~ersozalcomrnunication with David Lindahl. July 13, 1982.

corporation and to provide a five-year moratorium on its use in foreign
cars imported to the United States.
Following the demonstration, the Standard Oil Company of Ohio
(Sohio) expressed interest in the Webster-Heise valve.

In arranging

for further testing, Sohio noted that: 101

...

The data from these previous tests do indicate
the potential for reduction in octane, improved fuel
economy, reduced emissions, and possibly improved drivability. Together these benefits, if realized, could
represent significant value. Therefore, we are now
exploring ways to further evaluate the valve.
Sohio urged the Ford Motor Company to test the valve as part of a
joint project.

Ford agreed to a three-week test, to be followed if success-

ful by an eleven-month testing program with the Webster-Heise Corporation.
Ford required that Sohio not participate in the test and that no disclosures
of data be made while the tests were being conducted.
The tests were conducted at the Ford laboratory in Dearborn in late
January, 1981.

The baseline tests were conducted prior to the arrival

of Webster and Heise.

In the first test with the valve (Figs. 16 and 17),

significant gains were shown in torque and fuel economy (see Test 5,
Summary of Tests).

Ford was concerned, however, that some of these gains

might be due to the fact that the baseline engine (without the valve)

101 Richard D. Smith (Manager of Corporate Development, Standard
Oil Company of Ohio).
Personal communication to E.T. Taber, October 31,
1980. (The personal communications in footnotes 9-13 are in the public
record as part of Civil Actions 81-2867 and 81-2868, U.S. District
Court, District of Columbia).

had been contaminated by carbon deposits during the baseline tests.

11/
-

The second test (Fig. 18) was a very demanding wide-open throttle test.
The gains of the valve in this test were also apparent but above 3000

RPM they dropped to the level of the baseline production system with
heat due to the limited size of the prototype valve. Webster offered
to enlarge the valve to accommodate these testing conditions but was
121
told that no modification was necessary. -

Ford then exercised its

option under the testing agreement to terminate the tests.

Ford in-

formed Webster that "it is Ford's opinion that the Webster-Heise device
is not the most appropriate means of eliminating the necessity for carburetor heat" and that "the Webster-Heise device is not of interest
131
to Ford at this time." The spark-advance test conducted at the Ethyl Corporation is a
relatively severe engine test, although not as severe as the torque
test performed at Ford and ETC, and it simulates the rapid acceleration
sometimes encountered i n normal driving. The valve apparently worked well
in these tests, providing more fuel economy on low-octane gasoline than
did the baseline engine.

The early prototype valve completed the spark-

advance teat and did the same amount of work with approximately four
inches more vacuum.

This does not mean, however, that there was a re-

striction due to the presence of the valve (beyond the one-inch differen-

111 Robert D. Sanborn (Associate Counsel, Ford Motor Co.).
sona~communicationto S.F. Webster. June 12, 1981. p. 2.
121 Sherwood Webster. Personal communication to Donald E.
Petersen. February 6, 1981. p. 4.
13/
-

Sanborn, p . 2-3.

Per-

tial built into it).

It does mean that the same work could be done

on less fuel or more work could be done at the same vacuum, although the
effect diminishes as engine speeds increase.

In the spark advance tests

at Ethyl, despite the octane and fuel economy gains, no loss of power
was measured.

In the Ford wide-open throttle test, the valve size limita-

tion of the early prototype was encountered above 3000 RPM on 7 5 octane
(R+M/~) gasoline.

In order to accommodate these extreme conditions,

a second-generation prototype was made 30 percent larger, so that it
could descend further into the intake manifold under full throttle and
expose more screen area to prevent any unwanted pressure drop. The vacuum
differential at full throttle is about one inch due to the presence
of the valve (not to be confused with the vacuum created by the throttle
plate at lower RPMs) (see Test 6, Summary of Tests). Despite the presence
of manifold heat in Test 6, both the torque and fuel economy gains were
substantial.
In order to fully evaluate the new, larger prototype, Webster
and Heise decided to test it on a new state-of-the-art automobile
with electronic carburetion (which maintains a relatively constant
air/fuel ratio) and the latest pollution controls.

A 1982 Oldsmobile

Cutlass Supreme was purchased and a complete baseline test prior to
conversion was made at the Environmental Testing Corporation.

The

jacketed design of the Oldsmobile intake manifold, they discovered,
was not amenable to heat removal.

They also found that the design of

the exhaust gas recirculation (EGR) equipment did not allow for adjustment (less was needed to control NOx with the Webster-Heise valve)
without altering other calibrations in the closed-loop system.

With-

out the volumetric efficiency gains from a cooler manifold and with the

higher EGR, they were concerned that their gains might be reduced, particularly torque and NOx.

The test (Test 6, Summary of Tests), however,

showed significant gains over baseline, even with 75-octane fuel instead of 97-octane.

NOx decreased 45 percent despite a larger spark

advance, and other emissions also declined.

Fuel economy increased

from 31.4 MPG to 35.6 MPG, well above the EPA highway standard.
was also significantly increased.

Torque

To confirm these results, the test

was run again with the same (and in some cases even better) results.
The emissions were even rechecked on another computer to verify the
readings.

Webster-Heise concluded from this test that in an optimized

engine (with a cooler manifold and less EGR) even greater gains might
be achieved. 141

14/ Sherwood F. Webster.
AU~US~LO
1982.
,

Personal communication to David Lindahl.

VI.

STATUS AND OUTLOOK
The Webster-Heise Corporation makes several claims for its valve

and offers data from several tests (see Summary of Tests) in support of
its claims.

It is claimed by Webster-Heise that the valve does the

following:
1.

Reduces engine octane requirements by 10 or more
points;

2.

Reduces gasoline consumption by as much as 40
percent;

3.

Reduces the formation of nitric oxides (NOx) by
as much as 45 percent;

4.

Reduces the formation of carbon monoxide (CO) by
as much as 20 percent;

5.

Reduces the formation of unburned hydrocarbons
(HC) by as much as 10 percent;

6.

Increases torque as much as 20 percent;

7. Eliminates stalling and flooding, especially
on cold starts;

8. Reduces the formation of deposits that cause
engine wear and contamination of lubricants;
9.

Requires no maintenance.

Some automotive engineers, among others, are skeptical.
include the following:
1.

The pressure drop resulting from the presence
of the screen could result in a power drop.

2.

The reduction in manifold heating could be a
problem in sub-zero operation and could cause
an increase in HC emissions.

3.

It might "gunk up" over time and be rendered
inoperable.

Their concerns

4. There are more appropriate methods in development
to achieve the same gains.
These points, both pro and con, are addressed individually in more
detail in the sections on precombustion, combustion, and post-combustion
effects.

Overall, there is not enough evidence, based on the number of

tests, to be considered conclusive.
General Motors and Chrysler have reportedly expressed interest in
the valve but have conducted no formal tests.

R.M. Hokanson, the

Chrysler representative at the ETC test on October 15, 1980, made a
positive recommendation to his company:

151

I think this device has merit for our
company and recommended that we investigate
the possibility of testing this device on
our products as soon as possible.
Despite recommendations such as these, no further testing has been
done by any of the auto or oil companies.

Most of the major oil com-

panies have already made substantial investments in facilities to make
premium unleaded gasoline.

This product is more profitable (while it

is in short supply) than the other grades of gasoline and cannot be
readily made by many independent refiners.

The market for high-octane

unleaded gasoline is growing faster than any other grade because the
octane requirement of cars increases as engine deposits accumulate.
If all cars could use the same low-octane gasoline, it could make obsolete
many of the existing facilities built at great cost by the majors. It
could also eliminate the need for expensive octane additives and could
improve the competitive position of the independents with respect to

151 R.M. Hokanson (Chrysler Corp.).
"Demonstration of Intake
~ a n i f x dVariable Atomizing Valve." October 20, 1980. p. 2.

the major oil companies.

Use of the valve, however, could also save the

majors large investments in additional reforming facilities that might
far outweigh these competitive aspects.
One problem that Webster-Heise could expect to encounter on the
long path to acceptance would be that of competing technologies.

All

of the major automotive companies have invested large amounts of effort
and capital in devices that may not be compatible with the Webster-Heise
valve.

Fuel-injection has become increasingly popular as a means of

restoring some performance and diesels have found favor as a means of
improving fuel economy.

Some companies have committed considerable

resources to these approaches and may prefer to continue them rather
than to adopt a new device.

Others may conclude that in the medium

term (3 to 8 years) other approaches might be more competitive.

In

addition, most auto companies have research projects of long standing
that they may feel a need to protect from a competing device.

It may

be that the Webster-Heise valve will be found to improve the."in-house"
projects as well.

It has been suggested, for example, that the valve

could be useful on a spark-assisted diesel.

If so, companies that have

shown a strong interest in dieselization may find this development to
be complementary rather than contradictory. In any event, the reaction
of the auto companies to this device could be expected to vary considerably depending upon their own individual interests and priorities.
Another barrier of considerable significance is the "not-inventedhere" syndrome.

There is a strong preference in the auto industry

to use ideas developed "in house."

Innovation from outside the in-

dustry must compete with these projects in which an investment has

already been made.

"In-house" projects that address the same

problem will generally be given preference, if for no better reason
than that the companies are already familiar with them and have data
bases for them.

It is also possible that having been shown that a type

of improvement is possible, they may seek some other means of achieving
similar gains without employing a particular technology purchased from
outside.
Because of the high cost of automotive testing, the valve has been
tested on a limited number of test vehicles under a limited range of
circumstances.
like.

As a result the data base is not as large as most would

The more data that becomes available, the stronger are the con-

clusions that can be drawn.

Enough data has been obtained to demonstrate

the promise of the valve, but not enough has been collected to erase
all doubt among those who might risk large sums and professional reputations in developing and introducing the valve in mass-produced vehicles.
It would clearly benefit from further testing, especially in actual
road operation.
The cost of obtaining the rights to manufacture the Webster-Heise
valve for use on new automobile engines may or may not inhibit its acceptance.

The Webster-Heise Corporation has expressed willingness to

accept "standard and customary" royalty procedures followed in the domestic
auto industry.

That would consist of five percent of the manufacturer's

invoice cost for the first million valves, four percent for the second
million, three percent for the third million, and two percent for all
subsequent production. 2 1
Sherwood F. Webster.
~ u ~ u s T 3 11982.
,
161

Personal communication to David Lindahl.

The response of the auto companies to date has been noncommital.
Only one company, Ford, has formally decided not to use the valve.
may or may not; they have apparently not decided.

Others

Whether or not it

will be accepted at all by the domestic auto industry is currently uncertain.

If that proves to be the case, then foreign auto companies

(who have reportedly expressed interest in the valve) may choose to
pursue the necessary additional testing and development.

VII.

POTENTIAL BENEFITS
The tests which have been conducted so far indicate that the

Webster-Heise valve could have a significant beneficial impact on several
major issues.

The potential benefits described in this section are based

on the assumptions that the demonstrated gains, which so far are suggestive
but not conclusive, will be further substantiated in additional tests
and that the use of the valve would be widespread.

If that proves to be

the case, then a substantial reduction in crude oil requirements may be
possible at the refinery level.

In addition, greater fuel economy in

valve-equipped engines might lower the need for crude oil even more.
To the extent that the valve can reduce the emission of pollutants and the
need for toxic or carcinogenic additives to gasoline, air quality could be
improved.

If the valve proves to be a major advance in increasing the

fuel economy and performance of modern internal combustion engines, it
could be a major technological breakthrough that could attract new
interest to domestic automobiles and increase the competitiveness of
the U.S. auto industry.

A.

Refinery Feedstock Conservation
One of the problems facing refineries is the need to increase

octane and to make increasing amounts of unleaded gasoline, especially
premium unleaded, as the use of lead is phased out.

The manufacture of

unleaded gasoline has proven to be a costly process in terms of the extra crude oil consumed in making it and of the reconfiguration necessary
to increase its octane above the 82 or 83 level that it has when it comes
straight from the fractionating tower.

The extra processing used to

CRS-35
make unleaded fuels consumes about 9.2 percent more crude oil than does
straight-run gasoline, according to the Ethyl Corporation.

171

The

hydrocarbons used to increase the octane levels have many other uses
in the petrochemical industry and their allocations have been a source
of concern during oil supply emergencies.
The high cost of making premium unleaded gasoline, for which
demand is increasing faster than for any other gasoline type, has placed
the independent refiners at a competitive disadvantage to the major oil
companies.

Because the refining industry has been depressed and profits

have been limited or nonexistent in recent years, most investors have
been reluctant to lend the capital needed to build the octane improvement
facilities necessary to compete with the majors for a significant share
of the premium unleaded market.

The majors have had considerably more

financial flexibility in upgrading their production facilities during
this period.

As a result only the majors, to a large extent, are able

to make the high-octane unleaded gasolines that will perform satisfactorily
in new cars after engine deposits accumulate and their octane requirements
increase.

In the United States, there are 115 refineries (nearly 40 percent

of the total) that lack the catalytic reformers needed to make unleaded
gasoline, and all of these have capacities of 48,000 bld or less.

181

This is a major reason for the independent refiners' desire to have

171 George H. Unzelman (Ethyl Corp.).
"Return to Leaded Seen
savingT billion bbl of U.S. Crude." Oil and Gas Journal. Oct. 15,
1979. p. 106.
181 Oil and Gas Journal.
May 31T1982. p. 177.

"U.S. Lead Entitlements Urged."

allowable lead levels in gasoline increased despite strong environmental
opposition to that proposal.

Lead is preferred by refiners because it

is the least costly octane enhancer currently available. The Lundberg
Letter recently observed that "the emergence of premium unleaded allows
regular unleaded to drop in octane, and refinery profitability to be
enhanced. "

19/
-

If the entire fleet of automobiles in the United States could use
gasoline 10 octane points lower than that currently sold with no offsetting losses in fuel economy, performance, or emissions, it would
greatly reduce the crude oil requirement of the refining industry,
eliminate the need for large capital investments in facilities, improve the competitive position of small refiners, and reduce the
cost of making acceptable fuels for new cars.
In its analysis of the potential impact of the Webster-Heise
valve on refining, the PACE Company, well known for its consulting and
engineering work for the refining industry, reached the following conclusion:

201

When we evaluated the impact of a ten-octane
(R+M/2) reduction in our 1990 base case, over 600,000
barrels per day less crude oil were required to meet
the product slate. This reduction is due to fuel
savings in the refinery on the assumption that fuel
quality was reduced and less processing was needed.
If further efficiency can be gained through fuel/
engine optimization, savings would be greater.

191 Lundberg Letter. "As the Market Clears Artifical Price
~ p r e a d ~ ~ o l l a ~ s eVol.
. " IX, No. 32. June 11, 1982. p. 6.
201 John Matson (The Pace Company Consultants and Engineers).
person= Communication to S.F. Webster. April 10, 1981. p. 1.

PACE also noted that the production of lower-octane gasoline could
use components, such as naphtha, which have clear octanes of 40 to 65
and which are normally surplus for many refiners.
The objective, according to PACE, should be:

211

...

To simultaneously minimize fuel consumed in
the engine and the refinery. Most of the refinery
fuel saved in our analysis occurs in about the first
five octane number reduction, thus the optimum engine to take advantage of octanes in this range would
result in maximum miles per barrel of crude.
PACE also identified seven areas of refining that would be helped
by the production of low-octane gasoline that could be used in engines
equipped with the Webster-Heise valve.

221

1.

Reforming feed rates and severities would be reduced;

2.

Processing severity would be decreased and per-barrel
utilization of crude oil would be increased;

3.

The need for hydrocracking would be decreased;

4. The need for alternate blendstocks would be decreased;
5.

The availability for aromatics would be increased;

6. The need for liquefied petroleum gases (LPG's)
would be reduced; and

7.

The need for octane additives would be eliminated.

B.

End-Use Fuel Conservation
As indicated in the section on fuel economy, the improvements

in fuel economy with the Webster-Heise valve vary with the type of

211 Matson, p. 2.
221 The PACE Company Consultants and Engineers.
PACE ~
z and rPetrochemical
~
~
Seminar; Houston, Texas.
p. D-8.

Fourth Annual
November 1980.

driving and other factors.

The range of improvement is about 10 to 20

percent, with 15 percent possibly representative of the average improvement that could be expected in normal driving.

If the valve were in

use in all of the cars in the United States and if the best-case improvement of 20 percent were realized, the daily savings in gasoline consumption could be approximately 1.3 million b/d.

At the worst case improve-

ment of 10 percent, the demand for gasoline could be reduced by 650,000
b/d.

This, combined with the fuel conservation at the refineries, could

yield total savings of more than 1.25 million b/d (37 percent of total
crude oil imports in the second quarter of 1982 and 79 percent of the
crude oil imports from OPEC during that period).

23/

Because several years would probably be required for all of the
vehicles in the fleet to be equipped with the valve, the reduction in
gasoline consumption would be gradual as the number of cars using it
increase.

Nearly a decade would probably be required for most of the

fuel economy improvement to be realized.

This could be accelerated,

however, if the market acceptance of new valve-equipped cars were to
exceed the normal rate of replacement.

The primary point of introduc-

tion would most likely be in new cars, but retrofitting old ones is
also a possiblity.

If the engine deposits were removed, most older

cars could probably use the valve.

Cars five years old or newer might

require a change in EPA regulations preventing changes to an engine
once it is certified.

231 Petroleum Intelligence Weekly. "Plunge in U.S. Imports
~ a d i c a i iAlters
~
Crude Supply Mix." Vol. XXI, No. 35. August 30, 1982.
p. 1-2.

C.

Air Quality
The emission improvements indicated with the valve could

become a major factor in the debate over air quality in general and gasoline lead levels in particular.

Lead and other additives such as aro-

matics (benzene and others) are either toxic or carcinogenic and pose a
public health threat.

241

Reducing automotive pollution is of major

importance in achieving better air quality because it is responsible
for approximately 50 percent collectively of all the hydrocarbons (HC),
carbon monoxide (CO), and nitrogen oxides (NOx) that are emitted each
year.

251 A substantial reduction in these automotive emissions could

greatly improve air quality, particularly in urban areas where concentrations of pollutants are especially high.
The automobile industry has made considerable progress in
pollution control, but the results have been achieved at a high cost
to the consumer.

Performance has been sacrificed in many models in

order to achieve lower emissions and higher fuel economy in new cars.
The control devices themselves (such as dual-bed converters) can become
clogged or contaminated and can cease to function properly.

When they

malfunction, the pollution levels can rise to extremely high levels
and in some rare cases can prevent restarting once the engine is
stopped.

Because the controls can be troublesome and sometimes do not

work well enough even to get through the EPA certification process,
241 McGinty, Lawrence. "A Clean Case Against Lead in Petrol."
New ~czntists. May 27, 1982. p. 570.
251 F.V. Bracco (Princeton Univ.).
"Combustion and Chemical
~inetiz
Problems in Internal Combustion Engines. " In Progress in
Astronautics and Aeronautics, Vol. 62. American Institute of Aeronautics: Princeton, New Jersey. 1977. p. 162.

the automakers must occassionally ask for emission waivers.

In addition,

these controls are relatively complex and add up to $600 to the cost of
new cars.

g/

Much of the controversy is currently focused on lead because the
independent refiners have asked that the lead levels allowed in gasoline
be raised.

This request, if granted, would permit them to increase the

octane ratings of their gasolines so that they could compete at lower
cost with the major oil companies.

The majors, however, contend that

the exemptions gave the small refiners (and blenders who are not mentioned
at all in the regulations) a competitive advantage and, as a result, the
special exemption should be removed entirely.

271 The independent re-

finers, however, claim that they cannot afford the average investment
of $10 to 20 million each for the reformers necessary to chemically
raise the octanes of their unleaded gasolines.

g/

Extensive testimony was received by Congress on the subject,
most of it strongly against weakening of the lead standards.

Very

little support was offered for eliminating the standards completely.
A cost-benefit analysis prepared by EPA did not support an easing of
the lead levels, estimating that elimination of the standard would save

261 Joseph P. Biniek and David M. Lindahl. "Environmental
~ssues~ssociated
with the Auto Industry. " Congressional Research Service. November 2, 1981. p. 13.
Box."

271 Sandra Sugawara. "EPA Trying to Ease Out of a Leaden
Washington Post. May 21, 1982. p. A19.

281 Felicity Barringer. "Debate Over Lead in Gasoline Revs Up
~~ains? Washington Post. Oct. 15, 1981. p. A 11.

the refining industry $100 million per year but would cost between
$140 million and $1.4 billion per year to treat an additional 200,000
to 500,000 children for the lead poisoning that would be caused
by the higher lead levels.

291 An Environmental Protection Agency of-

ficial recently said in a memorandum that lead air pollution monitors
had repeatedly underestimated the lead content of air because they were
located "at sites which were not designed to measure maximum lead concentrations. 301
NOx is best known as the principal cause of smog, but it is also
an important factor in "acid rain."

The importance of NOx in the de-

bate over acid rain was summarized in a report for the Canadian Embassy:

311
NOx currently is responsible for
approximately one-fourth to one-third
of the acid rain--but this proportion is
expected to increase over the next two
decades. In parts .of the West, NOx is
already the major contributor to acid
rain. If current trends continue, by
1990 NOx-caused acid rain could equal
or exceed the acid rain caused today
by S02.

291 Joel Schwartz (Environmental Protection Agency).
"Health
E ffectrof Gasoline Lead Emissions.
Cover Memorandum to accompany
the Department of Housing and Urban Development official comments on
the lead phasedown proposal. May 11, 1982. p. 7 and 12.
"

301 Robert Kennedy (Chief of State and Local Controls Program
~ e c t i o zEnvironmental Protection Agency).
Internal Memorandum,
January 27, 1982. p. 1.
311 Wellford, Wegman, Krulwich, Gold, and Hoss (prepared
for thrcanadian Embassy. "Fact Sheet on Acid Rain. " 1982. p. 3-7.

NOx pollution also is associated with the
.production of ozone. High levels of ozone cause
crop damage, forest damage and a number of respiratory problems. Ozone, like acid rain, is a
product of atmospheric chemistry acting on
pollutants. It, too, is principally a transboundary pollutant; most of its damage is done
outside the state or province where the NOx
originates.
NOx from metropolitan centers along the
Pacific Coast is being deposited hundreds of
miles to the east in the Sierras and Rockies
in the form of nitric acid-contaminated rain
or snow. Studies published in Science magazine
show that precipitation with 4.6 pH (at least
five times normal acidity) is occurring frequently in parts of Colorado. Mountain lakes
in Colorado and California are becoming acidic,
with local residents concerned about potentially adverse consequences for the tourism
and recreation industries.
Most of the emission standards promulgated under the Clean
Air Act of 1970 are under pressure for revision.

Under the Act, the

1971 NOx levels were supposed to be reduced by 1976, but subsequent
administrative and legislative actions have delayed the deadlines
for NOx, CO (a poisonous gas), and HC (which can be carcinogenic).
The current NOx standard of 1 gram per mile would probably provide for
a steady reduction in NOx over the next decade but, if the auto industry request for a relaxation of the standard to 2 grams per mile
were granted, there would probably be no decrease but a slight increase instead. 321

The industry, on the other hand, claims that

these reductions would allow them to save billions of dollars in

321 Wellford, et. al.
-

"unnecessary controls" which could be used to increase the competitiveness
of their products and which might not have a substantial effect on the
environment and human health.

The standard for HC is 0.41 gram per mile,

and for CO it is 3.4 grams per mile.
Data from initial tests of the Vebster-Heise valve suggest that
its widespread use could make possible a solution to this economic1
environmental impasse.

Because of the substantial reduction of NOx

and CO (and HC to a lesser extent), the stricter standards could be met
with existing equipment.

It is very possible that some pollution con-

trols could even be removed outright or replaced with less expensive ones.
The dual-bed converter and closed-loop feedback systems, for example,
probably could be removed in.favor of simpler pre-1981 systems.

331

A smaller, less-expensive converter might be possible, and some controls
such as knock sensors probably could be eliminated. Even though some
catalytic conversion and exhaust gas recirculation would still be required, it may be possible to reduce the cost of necessary emission
controls by about $300 per car.

341 This could more than offset the

cost of the Webster-Heise valve, which almost certainly would cost less
than $100 each.
D.

Competitiveness of the U.S. Auto Industry
The U.S. auto industry is in trouble.

Since the turn of the

century, it has had a vital place in the economy; its success and its

331 Biniek and Lindahl, p. 18.
-

34/ Sherwood F. Webster.
~ i n d a h r August LO, 1982.

Personal communication with David

productive genius have long been a source of national pride.

For a

number of reasons., including increased .concerns over fuel economy
and air quality and the pressure from low-cost high-quality imports,
the domestic industry has serious problems to overcome.
The importance of the industry to the economy is well known.
Employment in 1978 was 14 million people, about one-fifth of all the
jobs in the Nation.

351

Indirectly, many more people in other indus-

tries rely on sales to the auto industry and on purchases by its
workers.

It is not surprising, therefore, that the current depression

in that industry has been a great setback for the economy in general.
In 1980, auto production was the lowest it had been in 20 years, while
auto imports (mainly from Japan and Germany) were at record highs.
In that year, the industry lost $4.2 billion, the largest loss in its
history, and severe losses have been experienced in 1981 and 1982.
Compounding the problem for the auto industry is its need to
meet this competition by investing in new models at a time when it
can least afford to do so.

The severe monetary losses have not only

cut into income but also into company reserves.

Faced with dwindling

reserves, limited cash flows, and record-high interest rates in a
highly competitive market, the industry is clearly in a dilemma.
The industry has repeatedly recognized the need for innovation in its
struggle for economic viability in the face of strong competition from
foreign manufacturers.

351
-

As the National Research Council and the National

Biniek and Lindahl, p. 3.

CRS-45
Academy of Engineering point out in their report on the competitive
status of the U.S. auto industry: 361
The transformation of the auto industry from
a mature, technologically quiet industry into a
hotbed of innovation and change creates opportunities for U.S. firms to attain competitive advantages
through development of radically new products. The
same, however, can be said of the Japanese and
the Europeans. Whether U.S.-based production regains lost market share by creating and exploiting
new markets depends on its ability to "out innovate"
its competitors.
The least costly path to recovery would be for the auto companies to make the most efficient use of existing equipment and
tooling while buying time to develop more advanced lines.

The Webster-

Heise valve, if proven successful and if accepted by the industry,
could easily be adapted to most new cars at little or no.additiona1
cost because unnecessary equipment probably could then be removed.
The only engines that it could not be used on are those that do not
have intake manifolds for the fuel such as port fuel-injection and
some diesel engines.

It might also be necessary to replace some

intake manifolds that have baffles with simpler, straighter manifolds to increase the opportunity for thorough mixing of the gasoline vapor and air.

Because it is self-regulated by engine demand,

the same size valve could be used on a maker's entire line of engines, thereby minimizing production costs.

Test data indicates

that the valve could be expected to increase fuel economy and torque,
to lower emissions and octane requirements, and to improve driveability, while possibly saving the maker (and ultimately the consumer)
361 National Research Council and National Academy of Engineerzg, p. 154-156.

about $200 per car.

Lower engine maintenance costs and operating

expenses, if realized across the fleet, could also be expected to increase buyer interest in new cars equipped with the valve.
When the valve was formally introduced to the automobile and
oil industries on October 15, 1980, the Webster-Heise Corporation
made an interesting proposal.

If offered to grant U.S.

automakers a

head start by preventing for five years the use of the valve on
foreign cars imported to the United States.

If accepted, this could

be expected to have the effect of shifting buyer interest away from
the imports and toward the domestic models.

The increased perfor-

mance and lower operating cost of the modified domestic cars would
probably increase their appeal in the marketplace.

If that proved

to be the case, then it is possible that the Webster-Heise valve
could enhance the competitiveness of the U.S.

auto industry.

VII

. IS THERE A FEDERAL ROLE?
In a market economy, improvements in automotive technology are

normally the province of private enterprise.

Such innovation is a matter

of entrepreneurial decision and risk; it ultimately succeeds or fails
in the crucible of the competitive marketplace.

This process, to which

virtually all products and services are subject, is constant and pervasive.

The Federal role, in theory and to a somewhat lesser extent

in practice, is largely to be a rational consumer in this market and to
regulate the marketplace in such a way that competition operates to the
benefit of society.

Occasionally, however, the Federal Government in-

tervenes to accomplish certain consensus national goals.

There are,

therefore, cases both for and against Federal encouragement of the
Webster-Heise valve.
Federal options in this matter include (a) no Federal action,
(b) Federal laboratory testing of the valve in the wide range of
vehicles and circumstances necessary for commercial utilization and
publication of the results, and (c) Federal field testing of the valve
by installation in a working fleet of Government vehicles over an
extended period with published results.
The case for Federal action along the lines of (b) or (c) might
be summarized as follows:

1.

There is reason to believe that the market is working
imperfectly in this case with the result that full
testing and introduction of the valve is being prevented or delayed and consumers are being denied its
benefits.

2.

Significant progress in meeting certain important national goals is being frustrated by corporate timidity
or an unfortunate confluence of market forces with

respect to the Webster-Heise technology.
interests being frustrated are:
a.
b.
c.
d.
e.
3.

The national

Fuel self-sufficiency
Reduction of severe balance-of-trade deficits
Competitiveness of the U.S. auto industry
Environmental health and well-being
Reduction of inflation

The potential social benefits of this technology far outweigh the market rewards to be reasonably expected by
auto manufacturers or commercial users of the WebsterHeise valve. For this reason, it is justifiable in
theory and in practice that society (through the
Federal Government) share in the cost of development and
testing.

4. The cost of Federal laboratory or field testing is
small relative to the potential benefits. Tests might
be conducted on the Postal Service fleet, where a large
body of information could be obtained on a wide variety
of vehicles. Other Federally sponsored tests might be
conducted by the National Aeronautics and Space Administration, the Environmental Protection Agency, the Department of Transportation, and the Department of
Energy, all of which have conducted similar tests in
the past.
The case against ~ed&al intervention with respect to the WebsterHeise valve might include the following:

1.

The market is not working imperfectly in this case.
The Webster-Heise technology has been in the marketplace for only two years; substantial testing has
occurred and the results are known to a limited
extent in the industry; much about the valve remains
unknown and corporate decision-making is in progress.
All of the claimed societal benefits rest on the
assumption that the technology works as claimed
and that it would be practically and economically
applicable to mass production and use. Similar
societal benefits were or could have been argued
over the past 50 years for scores of devices which
failed or had negative offsets in practical application.

. Market acceptance of the Webster-Heise technology also
rests upon its not being preempted by other technologies designed to achieve similar automotive goals;
toward these ends a considerable research effort is
currently underway both here and abroad. This is a
matter for testing and decision-making in the
market place without preferential government intervention.

4. Whether or not the market fully reflects the potential social benefits of this technology, if it works
as claimed and is competitively superior to-the
other approaches, there is more than ample incentive
for entrepreneurial venture investment. If the leading
automotive and engine makers and users show reticence
to begin testing there may also be cause for reticence
on the part of the Federal Government to subsidize
testing when there are other technologies competing
for market acceptance.

APPENDIX I
TECHNICAL ANALYSIS

A.

Pre-combustion effects
1.

Gasoline Vaporization

Gasoline will burn only as a vapor.

For that reason, all

engines attempt to vaporize gasoline prior to combustion, sometimes
achieving as much as 60 percent vaporization with the rest of the
gasoline in the form of droplets ranging in diameter from 20 to 100
microns or more.

These liquid droplets, along with the vapor and air,

are introduced into the combustion chamber and burn incompletely,
often producing detonation (engine "knock"), carbon deposits, high
emissions, unequal distribution to and within the cylinders, and
lower than optimum fuel economy.

Engines that have achieved 60-per-

cent vaporization prior to combustion have done so by using exhaust
0

heat to obtain high temperatures in the intake manifold (over 240

2).

These high temperatures can increase the vaporization of gasoline
by boiling it to the 60-percent level, but they have the associated
disadvantage of decreasing volumetric efficiency.

Fuel injection

is a technique used by the auto industry to increase volumetric efficiency by using cooler air but, because injected fuel has very
little time to vaporize and mix with the air in the cylinder, the
timing must be retarded with a consequent loss in fuel economy.
The optimum solution to this problem is to vaporize the gasoline at
0

low temperatures (around 130 F, the ambient temperature of the air
entering the intake manifold) so that the negative effects of high
temperature are not a factor. This however, had not proven practical
prior to the development of the Webster-Heise valve, although it

had been demonstrated experimentally by General Motors in single-cylinder
engine tests in the mid-1970's.

371

In order to convert a liquid (such as gasoline) to a gas, a considerable amount of energy is necessary to break the forces that hold the liquid
381 The amount of energy required is determined by the magnitogether. tude of the intermolecular forces to be overcome.

Generally, the com-

ponents having higher boiling ranges have higher chemical energy contents.
In the case of gasoline, this is complicated by the fact that it has at
least 16 different components, each with its own boiling point under standard
conditions (Fig. 5).

It is not necessary, however, to heat gasoline to

its final boiling point in order to achieve full vaporization.

As long

as the dew point of the gasoline (determined by the airlfuel ratio of
the mixture, the fuel composition, and the inlet manifold pressure) is
below the manifold temperature, then the fuel can be vaporized and
391
evenly distributed. -

--------------371 William R. Matthes and Ralph N. McGill, General Motors Research
Labs, "Effects of the Degree of Fuel Atomization on Single-Cylinder Engine
Performance," Society of Automotive Engineers Paper 760117 presented at the
Automotive Engineering Congress and Exposition; Detroit, Michigan, Feb. 2327, 1976.
381 Paul A. Sanders, Handbook of Aerosol Technology, Van Nostrand:
,
p. 264.
New ~ z k 1979.
391 G.A. Harrow. "The Effect of Mixture Preparation on Fuel Economy"
~
of the Gasoline Engine: Fuel, Lubricant and Other Effects.
in F U Economy
Ed. by D.R. Blackmore and A. Thomas (Shell Research Ltd.), John Wiley and
Sons: New York, 1977. p. 94.

FIGURE 5.

DISTRIBUTION AND BOILING RANGES OF GASOLINE COMPONENTS 401

Boiling Point in Still Air
at One Atmosphere
Component

(Degrees Fahrenheit)

Weight
(Percent)

Cumulative
Evaporation
(Percent)

Propane
Isobutane
Butane
Isopentane
Pentane
2-methyl but-2-en
Isohexane
Hexane
Benzene
2, 3 dimethylpentane
Heptane
Toluene
m-Xylene
3-ethyl toulene
Pseudo cumene
1, 3 diethylbenzene

401 D.J. Boam (National Engineering Laboratory (Glasgow)," A Computer
~ o d e l T fFuel Evaporation in the Intake System of a Carbureted Petrol Engine,"
IMECE Conference Publication 1979-9, The Institution of Mechanical Engineering,
London, 1979, p. 32.

CRS-54
FIGURE 6.

TYPICAL GASOLINE DISTILLATION CURVE

411
-

Because the heavier components of gasoline do not vaporize as
readily as the lighter ones.(because of their higher boiling points),
there is a substantial amount of "heavy ends" (approximately 50 percent
of the gasoline by weight) which is normally admitted to the combustion
chamber as liquid droplets (Fig. 6).

There they coat the piston heads

and cylinder walls and burn unevenly and incompletely, leading to crankcase dilution and contamination.,engine deposits, gum and varnish formation, and spark plug fouling.

The liquid gasoline gets past the rings

and into the crankcase where it dilutes the oil and reduces its viscosity.
The crankcase dilution is aggravated by the low engine operating temperatures associated with cold weather, especially in stop-and-go driving

411 D.E. Foringer (Gulf Reserch and Development Co.), "Gasoline Factors
~ f f e z i nFuel
~ Economy," Paper 650427 presented at the A P I Midyear Meeting,
May 1965, p. 243.

where engine temperatures do not reach levels high enough to evaporate

- This promotes engine wear,

the gasoline that is diluting the oil. 421
poor performance, and high emissions.

It has been widely suggested that

if the volatility of these heavy ends could somehow be increased, then
these negative effects would be greatly diminished. 431
The importance of vaporization of the fuel to the engine performance is shown in Figure 7.

In a standard engine, cold start problems

are common and even as it warms up, the engine is subjected to stalling,
carburetor icing, dilution, and engine deposits.

If the vaporization

level were about 95 percent of the intake mixture and the temperature
0

in the intake manifold maintained at a level above 125

F (both are con-

ditions which apply in Webster-Heise modifications), then the engine should
operate in a zone of maximum power, smoothness, and economy under all
speed and load demands.
FIGURE 7 .

-

EFFECTS OF TEMPERATURE AND VAPORIZATION ON ENGINE PERFORMANCE 4 4 1

I

0

10

20

I
10

WORT

TRIP ECCUOYV

I
40

50

I

I
60

% EVAPORATED

421
431
44/
-

Foringer, p. 2 4 3 .
Ibid., p. 243.
Ibid., p. 243.

I

70

I
10

I

SO

I

loo

The heat energy required to convert gasoline from the liquid to the
gaseous state with no temperature change is called the latent heat of
vaporization.

The heat is transferred by both conduction and convection

of energy between adjacent molecules. 451 Vaporization of gasoline may
be accomplished, therefore, by increasing its manifold temperature (as
in standard engines) or by lowering the pressure, by increasing the surface area of the droplets by forming more of them and reducing their diameters, and by increasing the heat transfer (as in the Webster-Heise valve).
To obtain lower emissions, greater power, lower octane requirements, and
greater fuel economy, it is far more effective to reduce manifold pressure
and to increase heat transfer to the gasoline rather than to increase
temperature.
At standard atmospheric pressure and temperature, some vapor will
evolve from gasoline and given enough time the gasoline will evaporate
completely.

Because the pressure in the intake manifold is far less than

one atmosphere (due to the vacuum created in the cylinders by the pumping
action of the pistons and by the one-inch pressure drop caused by the
46/
double screens), the boiling point of gasoline is lowered substantially. At the reduced pressure, latent heat is rapidly transferred to the
hydrocarbon molecules by the large number of air molecules surrounding
each fuel droplet, resulting in partial vaporization.

If finely atomized

gasoline is heated by the intake air in a zone of lower pressure (the

451 C.O. Bennett, Momentum, Heat, and Mass Transfer, KcGraw-Hill:
New ~ z k 1974,
,
p. 244.
461 General Motors Corp. Theory and Diagnosis of Chevrolet Carbuerecrs. Training Manual No. ST339-71, 1971, General Motors Corp. :
Detroit, p. 2.

partial vacuum of the intake manifold), it will undergo differential
vaporization (rapid vaporization due to the sudden drop in pressure).

471

This is the process at work in the Webster-Heise valve (Figure 8).
The Webster-Heise valve allows the throttle plate to be closed
to a greater degree than in a standard engine at the same speed and load.
The valve adds one inch of Hg to the intake manifold vacuum and the
throttle can add another 4 to 5 inches for a total vacuum that is 5 or

6 inches higher than standard at the same low speeds or loads.

The

vaccum decreases as the engine speed increases and, at wide-open
throttle, the vacuum difference is reduced to one inch (see Test 6,
Summary of Tests) because the vacuum due to throttling is no longer
present.

A differential of that size reduces the fuellair mixture densi-

ty ratio.

In a standard engine, this would normally create a small power

loss, but in the Webster-Heise modification this facilitates vaporization and is apparently more than offset by a variety of combustion benefits and by greater volumetric efficiency.

Although the density ef-

fect diminishes with higher speeds and loads as the vacuum decreases,
there are marked benefits at low and moderate speeds and loads.

These

include an effective reduction in compression ratio, contributing to the
tolerance for low-octane fuels.
The higher manifold vacuum created by the partial closing of the
throttle enhances the vaporization of the fuel.

More complete vapori-

zation increases the evenness of fuel distribution to the cylinders and
provides a more complete burn.

Fuel consumption at a given speed is

471 R.E. Collins (Physics Department, Univ. of Houston).
Flow
of ~ i u i d sThrough Porous Materials. Reinhold: New York. 1961.
p. 247-248.

reduced in near proportion to the density ratio.
also reduces exhaust emissions.

Lower fuel consumption

HC and CO are further reduced because

the fuel is more completely vaporized before combustion.

The lower ef-

fective compression reduces combustion peak temperatures and correspondingly reduces the formation of NOx.

Early tests suggest that torque is

enhanced by the better vaporization and distribution of the fuel.

Further

quantification of this effect on work output, engine speed, and fuel
requirments would be valuable in assessing the performance of the
valve.
According to the Webster-Heise Corporation, the valve has several
features that are unique, without any of which it would not be effective.
The valve, in self-regulated response to engine demand, moves up and down
in the intake manifold.

This is a critical characteristic because without

the ability to sufficiently.vary the screen area exposed to the airlfuel
flow as needed there would be a restriction that would impede the flow
of air and fuel and would result in a power drop.

For decades single

fixed screens have been tried, without success, to increase fuel vaporization, but because they were fixed they were optimized for only one
power requirement.

For all other states they actually constituted re-

strictions that were worse than no screen at all.

Because there was

only one screen involved, there was also no control over the scale or
intensity of the turbulence produced.
The Webster-Heise valve differs from these early attempts in that
it consists of two stainless steel screens pressed together, a coarse
stainless steel mesh (/I 50) followed immediately by a fine mesh (/I 120).
The openings in the two adjacent screens constitute a series of thousands
of micronozzles that force the liquid into small droplets (well under

10 microns in diameter) which quickly and totally vaporize within a few
inches of the outer screen because of three improvements in the quality
of the air that occur when it passes through the double screens:

58eJ

T 488'

E

n
P
E 308'
R
A
T
U 200R
E

THEORETICAL
(AT ONE fiTPl. 1

0 188'

WEBSTER-HEISE UALVE
WITH STRNDARD CARBURETOR
(FlT(1 ATm. )

F

FIGURE 8. EVAPORATION OF GASOLINE
0

*Differential vaporization begins at 125 F because the screens in the valve
act as a nozzle matrix that creates low pressure streams of turbulent, highenergy air and atomized fuel. The air temperature in the intake manifold
does not exceed 130 degrees F. Also note that vaporization with the W-H
valve takes place in a fraction of a second whereas the theoretical evaporation
curve is not time limited.
Source: Webster-Heise Corporation

(1) more internal energy (from impingement and compression)
(2) lower pressure (because of the Bernoulli Effect resulting from the air passing through the nozzles); and
(3) greater intensity of turbulence (due to the small
orifice sizes).
The screens must be tightly pressed together or the scale of
turbulence will not be great enough and the rapid vaporization effect
will be lost.

The vaporization effect diminishes rapidly, and may be

lost altogether, if the mesh sizes are varied by more than a few numbers.
Very little variation in design can be tolerated in either case if maximum vaporization is to occur.

Recent experiments suggest that even greater

results may be obtained if one of the screens is rotated 45 degrees (in the
same plane) with respect to the other so that the openings of the two
screens are completely random and not in registration.
Another important factor in the operation of the valve is the "radial
jump space" near the bottom of the valve.

The air and fuel droplets are

accelerated as they pass through the jump space and impinge on the vertical
screens and are compressed as they enter the matrix, at which time much of
their kinetic energy is converted into internal energy.
Flow through double screens of different mesh sizes is the equivalent of flow through a number of orifices or nozzles in parallel (a
nozzle matrix).

481 The pressure drop across the screens is controlled

by a vacuum valve at a level of about one inch of mercury, although the
pressure drop on the outer surface of the screen may be much greater (for

481 Robert H. Perry and Cecil H. Chilton. Chemical Engineers Handbook,Fifth Edition, McGraw-Hill: New York, 1978. p. 5-37.

a very short distance downstream from the valve) because of the relatively
high vacuum that is created between each of the nozzle jets.

The change

in pressure is apparently sufficient to permit differential vaporization.
Although the one-inch pressure drop is a slight restriction, it has the
effect of reducing fuel consumption. The small negative effect that the
one-inch pressure drop has on torque is more than offset by the greater
density and combustibility of the charge to the cylinders (cool air mixed
thoroughly with gasoline vapor) and the improved distribution to the weak
cylinders.

The greater mass of air available for expansion and the more

favorable timing result in a net increase in available torque, despite
the slightly higher vacuum.
491
Droplet size increases with the square of the orifice diameter. The orifices in the Webster-Heise valve are exceptionally small, ,0046

An orifice this size induces three times as

inches square or smaller.

much heat transfer as an orifice .008 inches in diameter.

501 Because

the air is moving faster than the fuel droplets inside the valve, its
high velocity can readily penetrate the liquid as it forms a film on the
inner screen, producing the necessary turbulence and energy transfer to
finely atomize the fuel.

511 Upon exiting the outer screen, transverse

shear forces are set up by the intersecting sprays, which work in conjunction with the rapid drop in pressure to cause the fuel to vaporize.

Be-

491 K. Masters, Spray Drying, John Wiley and Sons: New York, 1976,
p. 1 8 c
501
-

Perry and Chilton, p. 18-61.

511 Ibid., p. 18-64.
-

fore passing through the screen, the fuel is deposited as a film on the
coarse mesh openings by turbulence within the valve.

It is then accele-

rated through the smaller micronozzles (fine mesh), and then sheared by
the other existing streams on the outside of the valve.

This is impor-

tant because only a slight reduction in droplet size causes a marked increase in fractional evaporation.

521 Small droplets evaporate virtually
-

instantaneously, and a large proportion of the evaporation is accomplished
during the deceleration of the droplets.

5 3 1 The diameters of the drop-

lets exiting the valve are uniformly very small, probably less than
20 percent the size of the smallest droplets produced by the carburetor.

Because of the droplet small diameters and the conditions created both
inside and outside of the valve, most of the gasoline apparently vaporizes
almost instantly (within 0.2-2.0

inches from the valve) at temperatures

0

above 1 2 5

F.

The combined effect of internal circulation, oscillation, surface
distortion, acceleration, deceleration, shearing, and depressurization,
along with high intensity of air turbulence results in vaporization rate
that is probably close to but not quite 95 percent.

541

During experimentation with different screen sizes, it was found that
only the combination of the #50 interior coarse mesh and the #120 exterior

-

-

521
-

K. Masters, p. 2 9 9 .

531
541
-

Ibid., p. 3 0 8 .
Ibid., p. 2 9 6 .

fine mesh would achieve the differential vaporization effect, probably because the intensity of turbulence is increased proportionately more than
the scale of turbulence is decreased.

These two meshes produce a reverse

taper (wider spray) orifice with an exit diameter of at most .0046 inches.
This is much smaller than conventional state-of-the-art micronozzles which
have diameters as small as .008 inches.
produce a very fine droplet size.

These valve-actuator combinations

551 Because the heat and mass transfer
-

value that results from dispersion by the Webster-Heise valve is exceeding2
ly high (11.0046) or 47,260 (a gain of about 200 percent over a standard
engine), ultra-fine droplets are favored. 561 The smallest commercial
2
aerosol orifice is only (11.008) or 15,625 (a transfer rate one-third
that of the Webster-Heise rate).

Because the orifice diameter is so small,

the air stream is rotated and internally mixed within the nozzle and mixed
again externally as it emerges from the nozzle, resulting in very fine
sprays even at low feed rates and pressures.

57)

The Webster-Heise

valve can operate with a smaller orifice because the air is accelerated
by passing through the double down-tube and by the greater pressure differential between the intake manifold and the interior of the valve.
Turbulence appears to be essential to the high speed of vaporization
in the Webster-Heise valve.

The high friction produced by the passage of

air and gasoline through these screens results in an irreversible thermo-

551
-

Sanders, p. 105.

561 Perry and Chilton, p. 18-61.
571 Masters, p. 16.
-

dynamic process in the intake manifold of an operating engine.

581

Nonequilibrium thermodynamics (the extension of classical thermodynamics
to transport systems) is an area of science that is not yet well understood.
It is clear, however, that this kinetic energy is converted to latent
heat by high friction flow, thereby increasing the internal energy of
the air to the point where it can cause a change of state of the gasoline
in an environment of low pressure and high turbulence.
Turbulence has long been known to be essential to rapid vaporization.
It has long been known that turbulence can be effectively used to homogenize
591
fluid mixtures and to accelerate chemical reactions. -

The mass transfer

takes place through the relatively fast process of eddy diffusion and
can result in values 100,000 times that of normal molecular diffusivity.
6 0 1 A five-percent increase in turbulence in the air can increase
-

the rate of vaporization 20 to 30 percent. 611 The Webster-Heise valve creates
turbulence that is apparently over 200 percent higher than standard and may
yield potential increases in the vaporization rate of 800 percent or more.
Turbulent flows are always dissipative because viscous shear
stresses perform deformation work on the gasoline which increases its

581 Donald D . Fitts (University of Pennsylvania Chemistry Dept).
~ o n e ~ ~ l i b r iTherodynamics:
um
A Phenomenological Theory of Irreversible
Processes in Fluid Systems, McGraw-Hill: New York, 1962. p. 1.
5 9 1 Bennett, p. 1.
601 Perry and Chilton, p. 14-5.
611 H.R. Pruppacher and R. Rasmussen (Univ. of California. Dept.
"A Wind Tunnel Investigation of the Rate of
of ~ t G s ~ h e r iSciences).
c
Evaporation of Large Water Drops Falling at Terminal Velocity in Air."
Journal of the Atmospheric Sciences. July 1979. Vol. 3 6 . p. 1258.

internal energy at the expense of the kinetic energy of the turbulence. 621
In other words, the rapid movement of the air molecules and gasoline droplets are converted to internal heat energy upon deceleration after exiting
the Webster-Heise valve.

The intensity of the turbulence shears the main

flow after it passes through the Webster-Heise screens.
The most important characteristic of turbulence is its ability to
transport or mix momentum, kinetic energy, and contaminants such as heat,
631
particles, and fluids. -

The rate of transfer and mixing are several orders

of magnitude greater, therefore, than the rates due to molecular diffussion.

641 The diffusivity of turbulence is the single most important

feature as far as automotive applications are concerned because it increases the transfer rates of heat and momentum, both of which result
in vaporization at temperatures well below the normal boiling point.

651
-

In the case of the Webster-Heise valve, this takes place at a temperature
0

slightly above 125

F (the dew point of gasoline in an intake manifold).
0

The ambient intake manifold temperature is about 130

F if the exhaust

heat recirculation normally used in standard engines is removed and about
0

240

F

or more if it is employed.

621

press?

H. Tennekes and J.L. Lumley.
Cambridge, 1972. p. 3 .

631
641
651
-

Ibid., p. 7
Ibid., p. 7 .
Ibid., p. 2 .

A First Course in Turbulence. MIT

The fact that turbulence has'not been used to better effect in automobile engines illustrates the degree to which turbulence theories are
not understood.

As Tennekes and Lumley point out: 661

Randomness and nonlinearity combine to make the
equations of turbulence nearly intractable; turbulence
theory suffers from the absence of sufficiently powerful
mathematical methods. This lack of tools makes all
theoretical approaches to problems in turbulence trialand-error affairs. Nonlinear concepts and mathematical
tools have to be developed along the way; one cannot
rely on the equations alone to obtain answers to problems. This situation makes turbulence research both
frustrating and challenging: it is one of the principal
unsolved problems in physics today.
Perhaps the most important point made by Tennekes and Lumley is the
following:

671

This book has been designed to get this point
across. In turbulence, the equations do not give the
entire story. One must be willing to use (and capable
of using) simple physical concepts based on experience
to bridge the gap between the equations and actual
flows. We do not want to imply that the equations
are of little use; we merely want to make it unmistakably clear that turbulence needs spirited inventors
just as badly as dedicated analysts.
Screens have been used in other applications where similar conditions exist (but which do not involve combustion) and where similar effects were desired: 681

661 Tennekes and Lumley, p . 2-4.
671 Ibid., p. 4.
681 Alan Pope and Kenneth L. Goin (Sandia Corp).
-

Tunnel Testing. John Wiley and Sons: New York, 1979.

High-speed Wind
p. 101.

...

At large pressure-drop coefficients, turbulence
may be caused by screens and it is recommended that
several low-pressure-drop screens are preferable to a
single high-pressure-drop screen. This is the practice
normally followed in blowdown tunnel design.
The intake manifold equipped with a Webster-Heise valve is essentially a minute "wind tunnel" with a one-inch pressure differential or more
0

and an ambient temperature of about 130 F.

It has been observed that: 69/

Uniform fluid distribution is essential for efficient operation of
chemical processing equipment such as
contactors and reactors, mixers,
burners, heat exchangers, extrusion
dies, and textile-spinning chimneys.
To obtain optimum distribution, proper
consideration must be given to flow
behavior in the distributor, flow
conditions upstream of the distributor,
and flow conditions downstream of the
distributor...

A non-uniform velocity profile of
turbulent flow through channels or
process equipment can be smoothed
out to any desired degree by adding
sufficient uniform resistance, such
as perforated plates or screens across
the flow channel.
Droplet breakup is accomplished by the Webster-Heise valve through
three separate but related processes: 70/
1.

The impingement of the fuel and the air, after accelerating
across the radial jump space, on the screens.

2.

A pressure drop due to the presence of high-friction nozzles
(the combined screens).

691 Perry and Chilton, p. 5-49.
701 Perry and Chilton, p. 18-61.
-

3.

The high intensity of turbulence caused by the micronozzle
effect of the adjacent nonuniform screen openings.

In all of these, the density of the air involved is an important
consideration.

Perry and Chilton found that when a solid jet of liquid

(in this case gasoline) is being impinged upon by a gas (air), its relative velocity assumes a much greater importance than it does without

-

impingement. 711 Generally, there is a strong decrease in droplet size
with increasing gas density. It is important to note that in an engine
modified with a Webster-Heise valve, the intake manifold temperature
0

0

may be as low as only 130 F versus the 240 F that is normal in standard
engine (the extra heat recirculation can be removed because it is no longer
necessary for the vaporization of gasoline).

Thus, the cool air is much

denser and capable of greater droplet size reduction because of its greater
dynamic force.

721
-

There are four flow regions associated with a valve of this type: 731
1. Region of flow 'establishment--a short region
whose length is about 5 nozzle diameters or slot
heights (for a slot of infinite width).
The fluid
within the cone or core of same length has a velocity about the same as the initial discharge
velocity.

2. A transition region that extends to about
8 nozzle diameters, slightly less for slots.
3. Region of established flow-the principal
region of the jet, extending to about 100 nozzle
diameters or about 2000 slot heights.

711 Ibid., p. 18-59 -- 18-61.
721 Masters, p. 212.
731 Perry and Chilton, p. 18-49.
-

4. A terminal region where the residual
center-line or maximum velocity reduces rapidly within a short distance. For air jets,
the residual velocity will reduce to less than
1 ft./sec., usually regarded as still air.
Virtually all of the droplet breakup (and much of the vaporization) probably occurs within the first one-half inch after exiting the
outer screen (113 nozzle diameters times a nozzle diameter of .0046
inch).

The time required for this phase dispersion is about 13 milli-

741
seconds. The rapid rate of vaporization in the Webster-Heise valve is
highly dependent upon the unusually high internal energy of the air
and the rate at which it can be transferred to the fuel droplets which

-

also are subject to an increase in their own level of internal energy. 751
Pierce has shown that: 761
For an adiabatic flow with zero shaft work, the
changes in system directed kinetic energy will
result in system temperature changes with changes
in the internal energy content and distributions
in the various degrees of freedom...

As the gas is decelerated, there is an energy
exchange between the directed kinetic energy of the
gas stream and the internal energy of the gas itself. Assuming an adiabatic stagnation, then all
of the directed kinetic energy must manifest itself
as an increase in internal energy. The stagnation
can occur so rapidly, however, that the vibrational
degree of freedom may not accept its share of this
directed kinetic enegy as rapidly as necessary to
741 Perry and Chilton, p. 18-60.
-

-751. Sanders, p. 146.
761 Felix J. Pierce (Virginia Polytechnic Institute Department of
~ e c h a x c a lEngineering).
Microscopic thermodynamics: The Kinetic Theory
and Statistical Thermodynamics of Dilute Gas Systems. International
Textbook Company: Scranton, 1968, p. 284-303.

insure that equilibrium exists. Then since the
total energy is constant, the active degrees of
freedom must accept more energy than equilibrium
requires to compensate for the deficiency in
energy content of the lagging degree of freedom...
In the flow through the shock front there is
a sharp reduction in the directed kinetic energy
of the gas. Assuming adiabatic flow along stream
tubes, then this directed kinetic energy must be
transferred to the gas molecules and manifest itself as intrinsic or internal energy of the gas.
Since the vibrational degree of freedom is slow
in acquiring its share of this new energy, a nonequilibrium situation can occur where initially
virtually all this transformed directed kinetic
energy is absorbed by the active translational
and rotational degrees of freedom, and almost
none is absorbed by the inert vibrational degree
of freedom.
Another very important mechanism acting concurrently with the
turbulence the Webster-Heise valve is differential vapor recoil.

This

principle, despite its dramatic effects on vaporization (especially at
low temperatures), has not been well understood outside of research
laboratories. 77/ The Webster-Heise valve is apparently the first
application of this principle to automotive use.

Palmer has described

781
the effects of vapor recoil on the evaporation rate: -

A mechanism for inducing spontaneous convection,
that of instability induced by differential vapour
recoil, was first noted and correctly interpreted by
Hickman in 1952 but has since attracted surprisingly
little attention despite its dramatic effect on the
evaporation of liquids at pressures below 1 Torr.

771 Harvey J. Palmer (Distillation Research Laboratory of the
~ o c h e z e rInstitute of Technology). "The Hydrodynamic Stability of
Rapidly Evaporating Liquids at Reduced Pressure." Journal of Fluid
Mechanics, Vol. 75, Part 3, 1976, p. 487.
781 Ibid., p. 487-489.
-

Hickman (1952) has shown that an increase as high
as 20-fold in the liquid evaporation rate may be
enjoyed if the interface is disrupted by differential vapour recoil. The onset of such convection
appears as a sharp transition from a relatively
quiescent evaporating liquid surface as the pre-.
sure above the liquid is decreased.
Because mass must be conserved, the change
in fluid density during evaporation results in a
discontinuity in both the fluid velocity normal
to the interface and the rate of transport of
linear momentum across it. Momentum must also
be conserved. Therefore the discontinuity in
velocity results.in a downward force on the interface (vapour recoil) which increases with
evaporation rate and with an increase in the
density ratio of the liquid and gas phase.
Since the density of the gas phase is linearly
proportional to the pressure, the magnitude
and, thus, the importance of this vapour recoil force increase markedly as the pressure
is reduced.
If a liquid in contact with its own vapor is evaporated at low
pressure, interfacial heat transfer and evaporation rates can be increased dramatically by the onset of interfacial convection by differential vapor recoil.

791 The resulting discontinuity produces a

downward force on the interface (vapor recoil) which increases with the
increasing evaporation and the decreasing pressure.

Palmer has

demonstrated that this mechanism dominates interfacial behavior for
evaporation into a. partial vaccum.

801 This same research pro-

vides the explanation for the likelihood that the Webster-Heise vaporization rate is probably on the order of 95 percent rather than 100
percent (compared to approximately 60 percent prior to combustion in
791 Harvey J. Palmer (University of Rochester).
"Enhanced Interfaciar~eatTransfer by Differential Vapor Recoil Instabilities." International Journal of Heat and Mass Transfer, January 1981, p. 117.
801 Ibid., p. 118.
-

warmed-upsstandard engines).

Experiments and stability analyses have

shown the extreme sensitivity of the vapor recoil mechanism to interfacial contamination such as engine oil and water (from condensa811 As a result, the interface (between the liquid and vapor
tion). phases) will still develop some "torpid" patches about 5 percent of the
time because evaporative fluxes are suppressed wherever the less volatile
material accumulates on the surface. 821
Phase changes of fluids in pipelines have been observed for many
years.

In pipelines, this is an unwanted effect, but it serves as a use-

ful analogy in explaining the way in which gasoline flashes to vapor upon
exiting Webster-Heise valve and entering the intake manifold, which is
very much like a pipeline in that it is a tube transporting a liquid
which is subjected to pressure changes.

In a pipeline, differential

vaporization occurs because of the rapid relative velocity of the gas
phase.

831 As the saturated liquid flows through the pipe, friction

(as in the Webster-Heise screens) causes a pressure drop in the direction

841 The mass transfer rate from the
851 The
gas back to the liquid phase is zero (or very close to to it). of flow followed by vaporization.

811 Ibid., p. 118.
821 Harvey J. Palmer (University of Rochester).
"Spontaneous ConvectiG in Organic Liquids'Evaporating at Reduced Pressures." The Petroleum Research Fund ~rant#9146-AC~,
October 30, 1980, p. l.
831 Mohammed Anis and Paul Buthod. (University of Tulsa, Depart"How Flashing Fluids Change Phase in
men,t of Chemical Engineering).
Pipelines." The Oil and Gas Journal. June 24, 1974. p. 150.
841 Ibid., p. 151.
851 Ibid., p. 151.
-

vapor is swept away without contributing to the equilibrium composition,
promoting further vaporization.

The cooling effect accompanying the pres-

sure drop is much less than would be predicted in an equilibrium model
and apparently has the effect of increasing the volatility of the
liquid.

861
2.

Mixing
Mixing is a critical part of the pre-combustion phase of the

operation of a gasoline-powered engine.

It has been somewhat neglected

in current engine designs in which only limited mixing occurs due to
the presence of baffles and ridges in the intake manifolds.

This not

only is a relatively ineffective way to mix air and gasoline, it often
has a negative effect in that it provides numerous opportunities for
the liquid gasoline issuing from the carburetor to collect on the walls
of the intake manif old.
Harrow has described the compromises that current engines represent because of imperfect mixing:

...

'

Traditionally, at full throttle, part of the
latent heat of-vaporizationof the fuel is used to chill
the mixture entering the engine and thus to increase the
maximum power. In the absence of a perfect mixture preparation system which will provide both a chilled mixture
and a fully atomized fuel, engine inlet manifolds have
to cope with mixtures of liquid and vapour. A consequence of this need to combine several functions is that
an engine mixture preparation system is a package which
represents the manufacturer's best compromise between
the conflicting requirements of power, emissions and
economy. The result is invariably sensitive to minor
changes in the carburation and inlet system geometry,

861 Anis and Buthod, p. 151.
-

which can give an improvement'for one type of engine
87/
condition at the expense of performance in another. The engine manufacturer tries to ensure uniform
distribution of fuel between the cylinders by providing a hot spot to transmit exhaust heat to the
mixture and by drawing some of the inlet air to the
engine from around the exhaust manifold. The inlet
manifold is also designed to permit a certain amount
of liquid fuel to flow freely to the cylinders.
These procedures are not normally very effective, and
almost invariably some fuel maldistribution does
occur. 881

A homogeneous mixture of gasoline vapor and air is the ideal condition for the inlet charge of a gasoline engine.

891 Vaporization

greatly improves the mixing rate but, even in high-heat engines, the
charge is still far from homogeneous by the time it reaches the entrance
to the cylinders.

This is because insufficient turbulence is available

to cause the gasoline vapor molecules and air molecules to associate
completely.

It is compounded by the fact that many intake manifolds are

not sufficiently large to permit good mixing.
The Webster-Heise valve, by design, forces the gasoline vapor
and air to mix thoroughly within a short distance from the outer screen.
The high turbulence and shearing forces subject both components to an
intense mixing process.

Because the gasoline is in a vaporized or finely

atomized state, it is far less likely to impinge and recondense downstream
in the intake manifold. To reduce this possibility, all baffles and other

87/ Harrow, p. 89.
88/ Ibid., p. 93.
89/ J.R. Goulburn (Queen's University) and D.W. Hughes (New University
of ~lzer). "Mixing of Vaporized Petrol and Air in Automobile Inlet Systems."
In Fuel Economy and Emission of Lean Burn Engines, Institute of Mechanical
Engineers Conference Publication 1979-9, June 12-14, 1979. p, 97.

other obstruction$ are removed to provide a straight and clear path to
the intake valve for each cylinder.
The mixing principles employed in the Webster-Heise valve have
been known for some time.
Ashley, have observed:

As Goulburn and Hughes, based on work by

90/
-

There are two important principles: break
the stream down into a series of smaller streams
to speed up mixing and break down stratification
patterns; then pass the streams across and through
one another to redistribute major stratification
patterns. Multiple jets tend to overcome two undesirable characteristic~of all of the natural
mixing means, which are a relatively unmixed core
inside a well mixed outer envelope, and insufficient turbulence.
A design of mixer was produced which met
the above criteria and had the added advantage
that the heat transfer fins in the vaporizer
could, with some modification, also be used
to produce a series of jets of mixture directed so that adjacent layers of jets have
an interface where fluid shearing will
occur. Consider a vaporizer with horizontal
fins, and consider one flow passage between the
fins. At the end of the passage the flow encounters vertical deflector tabs positioned at
45 degrees to the flow turning the flow to the
left (say).
The flow passages immediately above
and below will have deflector tabs set as 45 degrees to the flow, but turning the flow to the
right. The two layers of flow will then, at
their interface, be shearing across each other
at 90 degrees.
Virtually the same conditions.exist in the Webster-Heise valve.
The benefits of improved mixing have been described by Harrow and
are well worth considering in the case of the Webster-Heise valve.

90/ Ibid., p. 100.
91/ Harrow, p. 115.
-

%/

(1) The effect of mixture quality on fuel economy is
significant and increases in importance the weaker the mixture strength becomes. It is of particular importance for
smooth engine operation under transient conditions.
(2) In multi-cylinder engines, good mixture quality
eliminates intercylinder fuel maldistribution and allows
the carburetor to be tuned to the maximum-economy mixture
strength.

(3) Under cold running conditions, good mixture quality
allows minimal use of the choke, thereby reducing short-trip
fuel consumption.

(4) With a perfect mixture preparation system, at least
part of the engine power could be controlled on mixture
strength alone. This would significantly improve part-load
fuel economy.
(5) Many devices exist for improving mixture quality.
They improve fuel economy, however, only if the mixture
strength and spark timing are adjusted correctly to
exploit the benefits that they confer.
3.

Distribution
Fuel distribution in conventional engines is a problem that is

widely recognized.

For efficient combustion and smooth engine operation,

the air and fuel must be thoroughly and uniformly mixed, delivered in
equal quantities to each cylinder, and evenly distributed within each
cylinder.

921 It is generally acknowledged that the best way to

achieve this is through a homogeneous charge:

z/

The process whereby the gasoline fuel and
air are metered in the desired proportions and
then mixed has been isolated as one of the key
elements in making improvements in engine combustion, hence in efficiency and products of
921 F.J. Marsee and R.M. Olree (Ethyl Corp). "Distribution Factors
That Influence Emissions and Operation of Lean Burn Engines." Fuel Economy and Emissions of Lean Burn Engines, Automobile Division of the Institution of Mechanical Engineers, I Mech E HQ, June 12-14, 1979, p. 129.
931 Goulburn and Hughes, p. 97.
-

combustion. It has been conclusively established
that a homogeneous mixture of gasoline and air
is the best condition for the inlet charge of
a gasoline engine...
In actual practice, however, the mixture in the intake
manifold (even with the addition of heat) is not completely vaporized.
As a result, the quality and quantity of the fuel charge reaching the
cylinders vary considerably.

941

Because this distribution is un-

equal, some cylinders produce more power than others and some will
have a greater tendency to detonate than others. =/

If the car-

buretor is adjusted to provide an adequate mixture to the weak
cylinders, then the other cylinders will receive a mixture that is
far too rich.

The industry has compromised, therefore, by accepting

weak and rich cylinders in order to obtain sufficient performance from
the other cyl

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3A82-176ENR. Public record. Not legal advice.
