- CVCC can also be used to represent a consonant-vowel-consonant-consonant syllable
A syllable is a unit of organization for a sequence of speech sounds. For example, the word water is composed of two syllables: wa and ter. A syllable is typically made up of a syllable nucleus with optional initial and final margins .Syllables are often considered the phonological "building...
pattern.
CVCC is a
trademarkA trademark or trade mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or services from...
by the
Honda Motor Companyis a Japanese multinational corporation primarily known as a manufacturer of automobiles and motorcycles. Honda is the world's largest manufacturer of motorcycles as well as the world's largest manufacturer of internal combustion engines measured by volume. Honda surpassed Nissan in 2001 to become...
for a device to reduce
automotive emissionsPollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms . Pollution can take the form of chemical substances, or energy, such as noise, heat, or light...
called
Compound Vortex Controlled Combustion. This technology allowed Honda's cars to meet
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
emission standardEmissions standards are requirements that set specific limits to the amount of pollutants that can be released into the environment. Many emissions standards focus on regulating pollutants released by automobiles and other powered vehicles but they can also regulate emissions from industry, power...
s in the 1970s without a
catalytic converterA catalytic converter is a device used to reduce the toxicity of emissions from an internal combustion engine. First widely introduced on series-production automobiles in the U.S. market for the 1975 model year to comply with tightening EPA regulations on auto exhaust, catalytic converters are...
. A type of
stratified charge engineThe stratified charge engine is a type of internal-combustion engine, similar in some ways to the Diesel cycle, but running on normal gasoline. The name refers to the layering of fuel/air mixture, the charge inside the cylinder....
, it first appeared on the 1975
ED1 engine.
The 1983
Honda PreludeThe Honda Prelude is a sports coupe produced by Japanese automaker Honda from 1978 until 2001. The two-door coupe spanned five generations and was discontinued upon the release of the fifth-generation Honda Integra or Acura RSX Type-S in North America in late 2001, due to its decreasing sales and...
(the first year of the second generation of Preludes) used a CVCC design
and a catalytic converter to reduce emissions, called CVCC-II along with 3 separate side-draft carburetors (instead of a single carburetor with an extra venturi for the rich mixture).
- CVCC can also be used to represent a consonant-vowel-consonant-consonant syllable
A syllable is a unit of organization for a sequence of speech sounds. For example, the word water is composed of two syllables: wa and ter. A syllable is typically made up of a syllable nucleus with optional initial and final margins .Syllables are often considered the phonological "building...
pattern.
CVCC is a
trademarkA trademark or trade mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or services from...
by the
Honda Motor Companyis a Japanese multinational corporation primarily known as a manufacturer of automobiles and motorcycles. Honda is the world's largest manufacturer of motorcycles as well as the world's largest manufacturer of internal combustion engines measured by volume. Honda surpassed Nissan in 2001 to become...
for a device to reduce
automotive emissionsPollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms . Pollution can take the form of chemical substances, or energy, such as noise, heat, or light...
called
Compound Vortex Controlled Combustion. This technology allowed Honda's cars to meet
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
emission standardEmissions standards are requirements that set specific limits to the amount of pollutants that can be released into the environment. Many emissions standards focus on regulating pollutants released by automobiles and other powered vehicles but they can also regulate emissions from industry, power...
s in the 1970s without a
catalytic converterA catalytic converter is a device used to reduce the toxicity of emissions from an internal combustion engine. First widely introduced on series-production automobiles in the U.S. market for the 1975 model year to comply with tightening EPA regulations on auto exhaust, catalytic converters are...
. A type of
stratified charge engineThe stratified charge engine is a type of internal-combustion engine, similar in some ways to the Diesel cycle, but running on normal gasoline. The name refers to the layering of fuel/air mixture, the charge inside the cylinder....
, it first appeared on the 1975
ED1 engine.
The 1983
Honda PreludeThe Honda Prelude is a sports coupe produced by Japanese automaker Honda from 1978 until 2001. The two-door coupe spanned five generations and was discontinued upon the release of the fifth-generation Honda Integra or Acura RSX Type-S in North America in late 2001, due to its decreasing sales and...
(the first year of the second generation of Preludes) used a CVCC design
and a catalytic converter to reduce emissions, called CVCC-II along with 3 separate side-draft carburetors (instead of a single carburetor with an extra venturi for the rich mixture). The following year a standard cylinder head design was used and the center carburetor (providing the rich mixture) was dropped.
In 2007, the Honda CVCC technology was added to the
Mechanical Engineering HeritageThe is a list of sites, landmarks, machines, and documents that made significant contributions to the development of mechanical engineering in Japan. Items in the list are certified by the Japan Society of Mechanical Engineers .- Overview :...
of Japan.
Construction and operation
Honda CVCC
enginesThe internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine the expansion of the high temperature and pressure gases, which are produced by the combustion, directly applies force to a movable...
have normal inlet and exhaust valves, plus a small auxiliary inlet valve which provides a relatively rich air / fuel mixture to a volume near the
spark plugA spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed fuels such as, aerosol gasoline, Ethanol, and Liquefied petroleum gas by means of an electric spark...
. The remaining air / fuel charge, drawn into the cylinder through the main inlet valve is leaner than normal. The volume near the spark plug is contained by a small perforated metal plate. Upon ignition flame fronts emerge from the perforations and ignite the remainder of the air / fuel charge. The remaining engine cycle is as per a standard four stroke engine.
This combination of a rich mixture near the spark plug, and a lean mixture in the cylinder allowed stable running, yet complete combustion of fuel, thus reducing CO (
carbon monoxideCarbon monoxide is a colorless, odorless and tasteless gas, yet very toxic to humans. It consists of one carbon atom and one oxygen atom, connected by a covalent double bond and a dative covalent bond...
) and
hydrocarbonIn organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. With relation to chemical terminology, aromatic hydrocarbons or arenes, alkanes, alkenes and alkyne-based compounds composed entirely of carbon and hydrogen are referred to as "pure"...
emissions.
Advantages over previous stratified charge engines
Honda's big advancement with CVCC was that they were able to use carburetors and they did not rely on intake swirl. Previous versions of stratified charge engines needed costly
fuel injectionFuel injection is a system for mixing fuel with air in an internal combustion engine. It has become the primary fuel delivery system used in gasoline automotive engines, having almost completely replaced carburetors in the late 1980s....
systems. Additionally, previous engines tried to increase the velocity and swirl of the intake charge in keeping the rich and lean mixtures separated. Honda was able to keep the charges adequately separated by combustion chamber shape.
Early Design Flaw
Some of the early CVCC engines had a problem with the auxiliary valves retaining collars vibrating loose. Once unscrewed, engine oil would leak from the valvetrain into the pre-combustion chamber, causing a sudden loss of power and massive amounts of smoke to emanate from the exhaust pipe. The condition simulated a blown engine, even though the needed repair was quite simple. Honda eventually came up with a fix involving metal retaining rings that slipped over the collars and prevented them from backing out of their threads.