Abbreviation for National Ambient Air Quality Standards
This is an air opening which was named after the National Advisory Committee for Aerodynamics. It was the American organization which developed the kinds of designs for low Drag air ducts for jet engines. NACA ducts are used on cars to force air for engine Breathing and cooling, for forcing air through the radiators, and for providing fresh air for the passenger compartment.
A plastic or metal covering. A headlight nacelle on a motorcycle is the bucket surrounding the headlight.
Abbreviation for National Automobile Dealers Association established in 1917
NADA Used Car Guide
A listing of current car prices, based on age, condition, and optional equipment; published by National Automobile Dealers Association
A vehicle brand of which models built between 1925 and 1948 (the classical era), with required application, are classic cars.
Abbreviation for North American Industrial Classification System. A coding system developed jointly by the United States, Canada, and Mexico to classify businesses and industries according to the type of economic activity in which they are engaged. NAICS replaces the Standard Industrial Classification (SIC) codes.
Fastener made from endless wire by cutting a point and forming a head at the shank end opposite the point. See
A unit of measurement of the wavelength of light. One nanometre = 10-9 metre= 10 Ångström units. Yellow light is about 550 nanometres.
Abbreviation for National Automotive Parts Association
An artificially produced petroleum or coal tar fraction with a volatility between gasoline and Kerosene. It is colorless and has an approximate boiling range between 50°C and 204°C. Used primarily as paint solvent, cleaning fluid, and blendstock in gasoline production, to produce motor gasoline by blending with straight-run gasoline.
A fuel in the heavy naphtha boiling range having an average gravity of 52.8 degrees API, 20 to 90 percent distillation temperatures of 143°C to 243°C, and meeting Military Specification MIL-T-5624L (Grade JP-4). It is used primarily for military turbojet and turboprop aircraft engines because it has a lower freeze point than other aviation fuels and meets engine requirements at high altitudes and speeds. Note: Beginning with January 2004 data, naphtha-type jet fuel is included in Miscellaneous Products.
One of three basic hydrocarbon classifications found naturally in crude oil. Naphthenes are widely used as Petrochemical feedstock.
Abbreviation for National Air Quality Strategy in the UK
(NA): Specialized lift trucks designed to be used in narrow aisles of 8 to 10 feet.
Narrow width chain
A chain used on multi-speed bicycles with a cassette of 8 or more sprockets.
(NAAQS) Ambient standards for criteria air pollutants specifically regulated under the CAA. These pollutants include ozone, CO, NO2>, lead, particulate matter, and SOx. Urban areas are required to achieve attainment in regard to ambient concentrations of these criteria pollutants.
National Automotive Technical Education Foundation
A consortium of automotive education experts which has established a steering committee to administer the CHAMP certification process at educational institutions.
National coarse thread
(NC) A standard for the threads of nuts and bolts in which the number of threads per inch is much fewer than a fine (NF) nut or bolt. Observe the difference in the number of threads per inch (TPI) of the NF and NC in the following chart. Also called Unified National Coarse thread (UNC)
National electrical code (NEC)
A code for the purpose of practical safeguarding of persons and property from the hazards arising from the use of electricity. It is sponsored by the National Fire Protection Institute. It is used to serve as a guide for governmental bodies whose duty is to regulate building codes
National Electrical Manufacturers Association (NEMA)
An organization which establishes certain voluntary industry standards relating to electric motors. These standards refer to the operating characteristics, terminology, basic dimension, ratings, and testing
National Environmental Policy Act
(NEPA) The National Environmental Policy Act requires federal agencies to integrate environmental values into their decision-making processes by considering the environmental impacts of their proposed actions and reasonable alternatives to those actions.
National fine thread
(NF) A standard for the threads of nuts and bolts in which the number of threads per inch is much greater than a coarse (NC) nut or bolt. Also called Unified National Fine thread (UNF). Observe the difference in the number of threads per inch (TPI) of the NF and NC in the following chart
The flag flown by a ship to show her nationality.
National Highway Traffic Safety Administration
(NHTSA) A US regulatory body which determines the regulations for vehicles.
(NLEV) Still under development, this program creates voluntary requirements which automakers can adopt in lieu of compliance with other vehicle emission control measures. The program applies to the manufacture of new light-duty vehicles and new light-duty trucks up to 6,000 lb GVWR. Vehicle exhaust emission standards have been established for the 13 northeastern states of the Ozone Transport Commission, applicable on and after the 1997 model year. Standards are extended to the rest of the U.S., except California, on and after the 2001 model year. In general, the standards lie between levels established for the federal Tier I Program and the California LEV Program. Automakers can use a manufacturer’s effective average standard to meet the non-methane organic gas standard. Vehicles are certified with California test procedures.
National motor freight classification
(NMFC) A publication for motor carriers containing rules, commodity descriptions, and classifications for nearly all shippable commodities.
National Off-Road Bicycle Association
(NORBA) The US governing body for off-road racing
National Petroleum Council
(NPC) An advisory body of appointed members whose purpose is to advise the Secretary of Energy.
National Pollutant Discharge Elimination System
(NPDES) The part of the U.S. federal Clean Water Act, which requires point source discharges to obtain permits.
National priorities list
The Environmental Protection Agency’s list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The list is based primarily on the score a site receives from the Environmental Protection Agency Hazard Ranking System. The Environmental Protection Agency is required to update the National Priorities List at least once a year.
National Traffic Safety Administration
(NHTSA) Under the U.S. Department of Transportation, NHTSA is responsible for reducing deaths, injuries and economic losses resulting from motor vehicle crashes. NHTSA investigates safety defects in motor vehicles, sets and enforces fuel economy standards, helps states and local communities reduce the threat of drunk drivers, promotes the use of safety belts, child safety seats and air bags, investigates odometer fraud, establishes and enforces vehicle anti-theft regulations and provides consumer information on motor vehicle safety topics.
National Transportation Safety Board
(NTSB) An independent Federal agency charged by Congress with investigating every civil aviation accident in the United States and significant accidents in the other modes of transportation — railroad, highway, marine and pipeline — and issuing safety recommendations aimed at preventing future accidents.
National Wooden Pallet and Container Association
(NWPCA) A national association with the goal of promoting the design, manufacturer, distribution, recycling and sale of pallets, containers and reels.
Gas in place at the time that a reservoir was converted to use as an underground storage reservoir in contrast to injected gas volumes.
NATO towing hook
Large, robust, four-bolt attachment towing pintle with top-closure and, usually, 360° rotational capability about the longitudinal axis originally specified for NATO 7.5 tonne military vehicles. Suitable for off-road towing.
Movement of a fluid caused only by temperature differences (density changes).
Circulation of a gas or liquid due to difference in density resulting from temperature differences.
The frequency at which an object, circuit, or system oscillates or vibrates when set in free vibration. Large heavy objects have low natural frequencies and small light objects have high natural frequencies.
The Natural Gas Act was passed in 1938, giving the Federal Power Commission (now the Federal Energy Regulatory Commission or FERC) jurisdiction over companies engaged in interstate sale or transportation of natural gas. The act instituted federal oversight of rates charged by interstate gas-transmission companies, and also limited certification authority. Nobody was allowed to build an interstate pipeline to deliver gas into a market already served by another gas pipeline without first obtaining a Federal Power Commission certificate. The principle aims of the Natural Gas Act were to: 1) provide a stable financial and regulatory environment for the financing and construction of interstate gas pipelines; and 2) prevent the ‘naturally monopolistic’ pipelines from engaging in undue discrimination and other feared abuses, including those attendant on their control by utility holding companies or major oil and gas producers.
Natural gas hydrates
Solid, crystalline, wax-like substances composed of water, methane, and usually a small amount of other gases, with the gases being trapped in the interstices of a water-ice lattice. They form beneath permafrost and on the ocean floor under conditions of moderately high pressure and at temperatures near the freezing point of water.
Natural gas liquids
(NGL) Those hydrocarbons in natural gas that are separated from the gas as liquids through the process of absorption, condensation, adsorption, or other methods in gas processing or cycling plants. Generally such liquids consist of Propane and heavier hydrocarbons and are commonly referred to as lease condensate, natural gasoline, and liquefied petroleum gases. Natural gas liquids include natural gas plant liquids (primarily ethane, Propane, Butane, and Isobutane; see Natural Gas Plant Liquids) and lease condensate (primarily pentanes produced from natural gas at lease separators and field facilities; see Lease Condensate).
Natural Gas Policy Act of 1978
(NGPA) Signed into law on November 9, 1978, the NGPA is a framework for the regulation of most facets of the natural gas industry. The gas market before 1978 was drastically different than the one currently existing in the United States. The changes in the market since the 1970’s have come partially from increasing technology, but also largely from changes in natural gas regulation. The Natural Gas Policy Act was one of the first efforts to deregulate the gas industry. Congress intended to allow the supply, demand, and thus the price of natural gas to be dictated by market forces, rather than regulation. Other deregulation bills include Order 636.
Natural Gas Vehicle
(NGV) A natural gas vehicle is a new breed of car, bus or truck that is powered by a natural gas, either in compressed or liquefied form, rather than the traditional gasoline or diesel fuel. These vehicles offer an extremely clean, safe and efficient alternative to traditional transportation. With the passage of the Clean Air Act Amendments and the Energy Policy Act of 1992, these alternative fuel vehicles are expected to proliferate in the later 1990’s. Already, major car manufacturers are offering natural gas vehicles, and there are over 700 fueling stations nationwide.
A term used in the gas processing industry to refer to a mixture of liquid hydrocarbons (mostly pentanes and heavier hydrocarbons) extracted from natural gas. It includes isopentane.
Natural Gasoline and Isopentane
A mixture of hydrocarbons, mostly pentanes and heavier, extracted from natural gas, that meets vapor pressure, end-point, and other specifications for natural gasoline set by the Gas Processors Association. Includes isopentane which is a saturated branch-chain hydrocarbon, (C5H12), obtained by fractionation of natural gasoline or isomerization of normal pentane.
Naturally aspirated engine
A conventional engine that takes in air at normal pressure, i.e. not turbocharged or supercharged. The opposite is forced-induction engine
Natural oxide film
A transparent film which forms naturally on an aluminum surface due to oxidation
Natural oxide skin
A transparent film which forms naturally on an aluminum surface due to oxidation
(NR) An elastomer produced from latex, a milky sap, obtained from the rubber tree (Hevea brasiliensis) and other plants. An elastic and porous form of rubber.
When ductile test specimens are subjected to a tensile test, they exhibit necking when the tensile force exceeds the yield strength of the material; necking results in a reduction of area, measured in percent after break of the specimen
An indicator on a dial, instrument, or gauge.
A thin rod or small tapered rod used to open or close a hole.
A valve with a long, thin tapered point that operates in a small hole or jet. The hole size is changed by moving the needle in and out.
A pair of items in a carburetor. The seat is usually a brass plug with a specially shaped hole to accommodate the needle which is a shaft with a pointed end. When the needle is fully seated in the seat, no gasoline can enter the float bowl. As the needle is lifted off the seat some gas pours into the float bowl. The needle moves when the Float in the float bowl drops below a set height.
A roller type bearing in which the many hardened steel needle rollers have a very narrow diameter in relation to their length. The design makes them particularly useful in situations where there is limited space such as the rod bearings on some pistons. Also called Quill-type bearing.
The distance between the mounting face of the disc and the rim centerline; the offset is referred to as negative when the inner attachment face of the wheel disc is shifted towards the inner side of the wheel. Opposite to Positive offset.
Negative offset steering
A Steering system which indicates the placement of the wheels. From the back of the vehicle, it appears as though the tires are tucked in where they contact the road. Although this system may appear strange, it actually does provide the benefit of helping a vehicle to stop in a straight line when the brakes are weak or the road friction is different on one side than the other.
The grey plate which acts as anode during battery discharge. Opposite of positive plate
The point toward which an electrical current flows through the circuit. It is designated by a minus sign (-).
A spark that jumps from the negative center electrode to the positive ground electrode of the spark plug, allowing a reduction in the high voltage required
A small spring in a bicycle suspension fork/shock that works against the main spring. It makes the fork respond better to small bumps, while not hurting large bump performance. It can be non-adjustable coil or adjustable air.
(NTC) a special type of thermistor whose resistance decreases as the temperature increases. Nearly all coolant temperature sensors are NTC thermistors
Negative temperature coefficient thermistor
(NTC) Electronic thermistor which decreases in resistance as temperature increases.
That terminal (such as that on the battery) from which the current flows on its path to the Positive terminal. It is usually marked with a minus symbol and is attached with the black cable.
Negative transducer EGR valve
A valve used on engines with a relatively low back pressure to provide the desired opening point and exhaust gas recycling rate
The measurement of the distance that a bicycle fork can travel past its maximum travel when rebounding from a bump. The negative travel allows the fork to top out without clunking, and can allow the fork to follow rough terrain better.
Abbreviation for the National Electrical Manufacturers Association which establishes certain voluntary industry standards relating to electric motors. These standards refer to the operating characteristics, terminology, basic dimension, ratings, and testing
A rubber-like substance used as an adhesive base, commonly used where oil and gasoline resistance is required. It also resists swelling action of pure aromatic chemicals and fuels
Neoprene synthetic rubber
Soft resilient material made of a synthetic chemical compound.
Abbreviation for National Environmental Policy Act which requires federal agencies to integrate environmental values into their decision-making processes by considering the environmental impacts of their proposed actions and reasonable alternatives to those actions.
A type of front bumper guard, typically made of chrome-plated steel tubing; extends horizontally from below front end and is curved upward; a pair of nerf bars is usually braced by a horizontal crossbar. In Australia it is called a roo bar.
A relationship showing that the electromotive force developed by a dry cell is determined by the activities of the reacting species, the temperature of the reaction, and the standard free-energy change of the overall reaction
An electrode potential corresponding to the reversible equilibrium between hydrogen gas at a certain pressure and the corresponding level of hydrogen ion activity.
A term used in weighing terminology which refers to cargo weight. (Tare weight = unloaded weight of a vehicle, Net weight = weight of the cargo, Gross weight = Tare + Net).
A switch which allows the starter to be engaged only when the automatic shift lever is in either park or neutral
The characteristic of a vehicle’s Slip angles where both front and rear are the same. In slippery conditions, both the front and rear tires will break loose at the same time so that the vehicle slides sideways rather than the rear end swinging around (oversteer) or the front end wanting to move to the rear (Understeer). A cornering condition in which the front and rear slip angles are roughly the same. Although seemingly an ideal state of balance, perfect neutral steer is not as stable as slight understeer.
A neutral charge particle forming part of an atom.
That part of an atom core which has no electrical potential; electrically neutral.
New car dealer
Major car dealership with a parts and service operation.
(NOS) New genuine parts for older models, referring mostly to spare parts that are normally no longer produced
(NOS) New genuine parts for older models, referring mostly to spare parts that are normally no longer produced
A unit of force. One newton is the force which acts on a mass of 1 kilogram to produce an acceleration of 1 metre per second per second.
Force exerted on an object that has mass of 1 kilogram and gravitational acceleration of 1 m/sec².
A metallic compound containing nickel and chromium, used in making high resistances
A silver-white metal usually used as an alloy in steel, bronze, brass and cast iron. It tends to increase corrosion resistance. It is added to 300 series stainless to provide corrosion resistance, increased strength in both high and low temperatures, and increased toughness in low temperatures. Nickel lowers the effects of work hardening, thus reducing traces of magnetism caused by cold forming and making material flow more freely in manufacturing.
Abbreviation for National Institute for Occupational Safety and Health
A fitting which is threaded to the end of a spoke. The nipple is seated in the holes of the rim and receive the threaded end of the spoke. The nipple has a slot at the top so that it can be quickly tightened a little, but the other end of the nipple has flat or square sides so that a spoke wrench can be applied to tighten the spoke into the nipple
A small, one-way valve used for injecting grease into a bearing.
A short, steel tube holding a thin rubber or plastic tube used for bleeding hydraulic fluid
A short piece of threaded pipe used to connect two fittings.
A model of automobile manufactured in Japan 200SX (1977-2002), 240SX (1989-98), 300ZX (1984-96), 350Z (2003-07), Altima (1993-2008), Armada (2005-07), Axxess (1990), Frontier (1998-2008), Maxima (1981-2008), Minivan (19__-90), Murano (2003-07), NX (1991-93), Pathfinder (1985-2007), Pathfinder Armada (2004), Pulsar (1978-90), Pickup (19__-97), Quest (1993-2008), Sentra (1982-2008), Stanza (1977-92), Titan (2004-08), Versa (2007-08), and Xterra (2000-07)
The hardening of steel by heating it for several hours in ammonia gas. Used on crankshafts
Also known as Buna-N rubbers, these adhesives have high strength, excellent aging properties and good chemical resistance, including resistance to both aliphatic and aromatic solvents and to most platicizers which cause bond failure of other adhesives. Nitrile has excellent resistance to petroleum oils and gasolines, to mineral and vegetable oils, but poor resistance to oxygenated solvents like acetone. It has good heat resistance and is the most commonly used adhesive material in applications exposed to hot oils
A paint which gives a deep, lustrous finish. It is used on old Jaguars but was prone to crazing and checking. Because spraying with nitrocellulose paints creates environmental problems, they are no longer used for volume cars
(NO2) A compound of nitrogen and oxygen formed by the oxidation of nitric oxide (NO) which is produced by the combustion of solid fuels. Mildly poisonous gas often found in smog or automobile exhaust fumes.
(NOx) In the combustion process, nitrogen from the air combines with oxygen to form nitrogen oxides such as nitric oxide and nitrogen dioxide. Nitric oxide is the main oxide of nitrogen emitted in raw exhaust gas, typically 90%; nitric oxide and nitrogen dioxide are severely toxic gases without emission controls, the exhaust of an spark ignition engine contains 0.3-1.5 kg of NOx per 100 litres of gasoline consumption
A closed cell material that’s impervious to gasoline and fuel additives; used as a float material
A performance system that injects nitrous oxide into the inlet manifold at the press of a button, thereby introducing a quick dose of extra energy and a burst of power. On a 6-cylinder or V-8 engines, the nitrous oxide system is intended to add up to 250 HP; it consists basically of a pressurized nitrous oxide bottle as used for welding, solenoids, an injector base plate for the carburetor, and steel pipes; the low vaporization temperature of nitrous oxide (-90°C) cools the A/F charge, dampening detonation and minimizing stress caused by increased load
Abbreviation for National Motor Freight Classification which is a publication for motor carriers containing rules, commodity descriptions, and classifications for nearly all shippable commodities.
Abbreviation for Non-Methane Hydrocarbons.
Abbreviation for Non-Methane Organic Gases
Abbreviation for normally open
Symbol for nitric oxide
Symbol for nitrogen dioxide
A description of a vehicle that suggests financial success and social distinction because of its overall aesthetics and proportions.
A rare or precious metal (such as gold, silver, mercury, platinum) which conducts electricity very well, resists corrosion, and is inert; some are used as catalysts in catalytic converters
A reduction in insurance premiums because no claims have been made
An optional extra for a new car at no extra cost
No fault insurance
A form of vehicle accident insurance in which the insurance company of each driver pays for the damages of its own driver regardless of who is at fault. So if you and I have an accident, my insurance company will pay for my damaged car and your insurance company will pay for your damages. If you don’t have insurance, my insurance company will pay for my damages even if I think you are at fault.
Low-temperature refrigerator cabinet in which no frost or ice collects on freezer surfaces or materials stored in cabinet…
The average distance between the joints (except for staggered pitch chains) of an assembled chain. In some cases, ‘joint’, as defined here, will be a center of flexure not specifically identified with individual parts of the chain.
A characteristic value used for pipeline systems to identify parts which belong together such as pipes, pipe joints, fittings, etc.; a nominal size for the inside diameter
The length of the shank of screws/bolts with flat bearing faces.
The length of shank plus height of head of countersunk bolts/screws.
The overall length of a stud minus the length of the stud end
A valve member which cannot be moved from its seat by a force applied to-the valve handle, or force applied by a plane surface to any exterior portion of the valve.
Any oil that does not have the ability to take up oxygen from the air to change it from a liquid to a solid state. Mineral oils are non-drying oils; so are a few vegetable oils
Group of metals and metal alloys which contain no iron.
Pure metal or alloy without an appreciable amount of iron such as aluminum, brass, copper, etc. Because they do not contain iron, they are not subject to rusting.
Evaporator which never collects frost or ice on its surface.
A gasoline blend or blendstock that cannot be shipped via existing petroleum product distribution systems because of incompatibility problems. Gasoline/ethanol blends, for example, are contaminated by water that is typically present in petroleum product distribution systems.
Typical nonhydrocarbon gases that may be present in reservoir natural gas, such as carbon dioxide, helium, hydrogen sulfide, and nitrogen.
An anti-lock brake system whose major hydraulic components are separate from the master cylinder, and are installed between the master cylinder and the wheel brakes Also called Non-integrated system or Independent ABS
An anti-lock brake system whose major hydraulic components are separate from the master cylinder, and are installed between the master cylinder and the wheel brakes. Also called Non-integral system or Independent ABS
Non-load-bearing flue gas baffle
A flue gas baffle, which does not add support, strength or rigidity to a heat exchanger or flue.
Steel alloys with sufficient quantities of manganese or nickel to render the steel non-magnetic. 18-8 (300 series chrome-nickel steel) is non-magnetic when annealed. Type 316 is non-magnetic in all conditions.
Non-Methane Organic Gases
(NMOG) The sum of non-oxygenated and oxygenated hydrocarbons exclusive of methane contained in a gas sample as measured in accordance with California’s non-methane organic gas test procedure.
Nonmethane volatile organic compounds
(NMVOC) Organic compounds, other than methane, that participate in atmospheric photochemical reactions.
A local or regional road linking villages and towns within a county or district.
A kickstart system on a motorcycle using the transmission input shaft and clutch hub to connect the kickstart lever to the crankshaft. For starting, the transmission must be in neutral and the clutch engaged.
Fuels that cannot be easily made or renewed, such as oil, natural gas, and coal.
Pallet with a bottom deck board configuration different from the top.
Nonroad alternative fuel vehicle
(nonroad AFV) An alternative fuel vehicle designed for off-road operation and use for surface/air transportation, industrial, or commercial purposes. Nonroad AFVs include forklifts and other industrial vehicles, rail locomotives, self-propelled electric rail cars, aircraft, airport service vehicles, construction vehicles, agricultural vehicles, and marine vessels. Recreational AFVs (golf carts, snowmobiles, pleasure watercraft, etc.) are excluded from the definition.
A centrifugal pump which is unable to evacuate and prime the suction line without external assistance. The opposite is Self-priming pump. Most centrifugal pumps are non-self-priming and require a flooded suction line
A drum brake design; each brake shoe is anchored, therefore no one shoe can assist in the application of the other; one shoe is self-energizing, the other is not
A drum brake in which each shoe is applied individually; the operation of one shoe has no effect on the other.
Non-servo drum brake
A drum brake design in which the application of one shoe has no effect on the other
A 4-barrel carburetor that has secondary throttle plates which open at the same time as the primary throttle plates, or a two-barrel carburetor with only one throttle shaft (both throttle valves open simultaneously)
Transfer fluids having a Gosselin rating of one (1), including water, Propylene glycol, mineral oil, polydimethyoil oxane, Freon and FDA-approved water additives. Such fluids are deemed essentially nontoxic by the BOCA Basic/National Plumbing Code or GRAS (generally recognized as safe) by the FDA (Food and Drug Administration).
Engine design which separates the engine crankcase and transmission case.
An electric motor housing that is not equipped with a fan for external cooling, but depends on convection air for cooling. It may be Totally enclosed or Explosion-proof
Non-vessel-operating common carrier
(NVOCC) A cargo consolidator of small shipments in ocean trade, generally soliciting business and arranging for or performing containerization functions at the port.
Non-volatile random access memory
A non-volatile memory that is used to store information for either short or long term usage. This type of memory can be written to. If external energy is removed from the device, the contents in memory are not destroyed.
A grinding disc which is made of very hard material used primarily for cutting.
The L-shaped tubing piece found on the side of Shimano V-Brakes and some other direct-pull cantilever bicycle brakes
Abbreviation for National Off-road Bicycle Association — the US governing body for off-road racing
A round key
Nordic Anti-Corrosion Code
A code developed by the Scandinavian automobile and consumer associations which stipulates that, as of January 1983, all cars must be free of surface corrosion for three years and free of perforation and weakening damage for six years
No rinse treatment
An application method of chemical conversion coatings by means of a roll coating system whereby no rinsing treatment is required
(n-Butane), technical Grade. A liquefied petroleum gas composed of a minimum of 95 percent n-butane (C4H10) which may contain other impurities such as Isobutane, Butylenes and Propane not in excess of 5 percent.
Thermal element charge which is part liquid and part gas under all operating conditions.
To remove internal stresses by heating a metal piece to its critical temperature and allowing it to cool very slowly.
An engine that intakes air or breathes without the assistance of a supercharger or turbocharger. At the start of compression, it operates on a cylinder air charge at a pressure very near to or slightly below atmospheric.
Normally aspirated engine
An engine which uses the factory installed carburetor or fuel injection system with its normal air filter, etc. It does not use modified air flow systems which pump more air into the engine. Usually this expression is used as comparison as in My modified intake puts out more horsepower than a normally aspirated engine. Also called Naturally aspirated engine or a free breather.
Abbreviation for new old replacement stock, or new old reproduction stock. These are parts that were aftermarket replacements, usually of the same quality, for the manufacturer’s parts. Or, they are parts that were reproduced by an aftermarket supplier using the same quality of materials and manufacture as the original manufacturer, but now are old.
North American Free Trade Agreement
(NAFTA) Agreement creating free trade among the United States, Canada, and Mexico. The NAFTA went into effect on January 1, 1994.
North American Industrial Classification System
(NAICS) Industry Classification between Canada, the United States and Mexico to increase compatibility of data with these countries. The classification is based on establishment rather than commodity. This classification system will be implemented with reference to year 1997 and data will be available in 1999.
North American produced
Motor vehicles assembled in Canada, the United States or Mexico.
The magnetic pole in a magnet from which the lines of force emanate; travel is from North to South pole.
North pole, magnetic
End of magnet Out of which magnetic lines of force flow.
Abbreviation for new old stock. These are parts that originally were available from the manufacturer of a vehicle. They have never been used, thus are new. But they also may have been on the shelf for decades, thus are old. Duplicates of parts for out-of-production cars that are issued by the original manufacturer for the restoration of older vehicles.
The process of raising a small peak (nose) in the center of the hood of a car, usually as part of a customized design.
A condition of a trailer where the load is heavier at the front than the back, which is the proper configuration. The nose-load is the amount of nose-heaviness (sometimes called trailer preponderance) measured at the tow-hitch and must be considered part of the towing vehicle’s payload.
A header, a situation where a vehicle or rider crashes or falls forward.
An insert for pop-rivet pliers that is used to allow various pop-rivet diameters to be used
A cover, usually of black soft plastic sheeting with flannel-like backing, that fits around the front end of a car. Also called nose bra. Compare Stealth bra. It protects the front portion of hood and fenders against damage caused by flying rocks, road debris and insects; attaches to car with bendable plates, straps, or hooks and grommeted edges; sometimes personalized with a vehicle logo; relatively common in the USA, but rarely found in Europe
A vertical weight on the center of the towing ball exerted by the vehicle being towed (on level ground). This must be within certain limits; generally between 110-165 lbs (50-75 kg) for car and trailer
A classical sedan shape which is sometimes called a three box design. When you look at the side of the car, the front section in front of the windshield is one box; the section with the doors and windows is the second box; and the third box is the trunk. Because the third box starts just below the back window, it is called a notchback.
A body shape which differs from a fast back. When a Fastback is observed from the side, there is a smooth line (curve) along the roof from the A-pillar to the back of the car. In a notchback, the roof is abruptly dropped down to the leading part of the rear deck (or trunk).
Notched rocker arm stud
A rocker arm stud with a notch worn in its side; a notched stud is more likely to break
A stringer (e.g., in a pallet) with two notches spaced for fork-tine entry, (partial four-way entry).
The action of changing the gears in a rough way which causes a slight crashing of gears. It is often caused by the clutch failing to disengage fully
A thin application of liquid asphalt emulsion and a single layer of stone, coated with asphalt (such as NYS #1 stone, which is about 1/2′ in size). The material is put down with a special paver. It cools and sets within minutes. The road is opened to traffic almost immediately after placement of material.
Oxides of nitrogen. A compound formed during the engine combustion process when oxygen in the air combines with nitrogen to form photochemical smog. Acid deposition, commonly called acid rain, occurs when sulfur dioxide (SO2) and, to a lesser extent, NOx emissions are transformed in the atmosphere and return to the earth as dry deposition or in rain, fog, or snow. Highway vehicles – autos, trucks and buses – account for nearly 30 percent of all NOx and non-methane hydrocarbons emitted annually in the United States. Burning any fossil fuel produces NOx, and it is difficult to generalize with respect to the relative NOx emissions of the various fuel types for different applications. However, the substitution of new high-efficiency gas equipment can offer significant NOx reductions, relative to older and less efficient equipment. For example, replacing a coal-fired electricity generating unit with a new gas-fired combined-cycle unit can reduce NOx by some 95 percent. It is at its worst when combustion is most efficient. It is produced because the air is 78 percent nitrogen. Combines with HC in sunlight to form PhotochemicalSmog. NOx emissions can be reduced by lowering peak combustion temperatures through lowering Compression ratios and by Recirculating exhaust gases.
Air rushing by the venturi at idle can cause fuel to drip from the discharge nozzle for the main metering circuit
A restrictor in the fuel filler neck of cars fitted with catalytic converters that prevents filling from leaded petrol pumps, which have larger pump nozzles
Abbreviation for National Petroleum Council — An advisory body of appointed members whose purpose is to advise the Secretary of Energy.
Abbreviation for National Pollutant Discharge Elimination System which is the part of the federal Clean Water Act, which requires point source discharges to obtain permits. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington State Department of Ecology.
Abbreviation for Northwest Pavement Management Association.
Three-element transistor made of two types of semi-conductor metals
1906 saw the launch of the Sulmobil, a three-wheeled vehicle with a 3.5 hp motorcycle engine. However, the Sulmobil was not a success. As a result, the first Original Neckarsulm Motor Car, with a 1308 cc four-cylinder engine and 10 hp, went into production the same year. The 1964 Wankel Spyder models are milestone cars.
Abbreviation for notify. When a mail order seller does not have the merchandise in stock, but expects to get it in the future, he tells a Customer the item’s status with NTF, which means he will notify the buyer when it is in stock.
Abbreviation for negative temperature coefficient resistor
Abbreviation for National Transportation Safety Board — An independent U.S. Federal agency charged by Congress with investigating every civil aviation accident in the United States and significant accidents in the other modes of transportation — railroad, highway, marine and pipeline — and issuing safety recommendations aimed at preventing future accidents.
Involving the inner part of an atom, the nucleus. Changes in the nucleus can release a lot of energy which can be used in the generation of power.
A location where nucleation, i.e., the formation of new crystal nuclei in supersaturated solutions, starts
A fastening device that is somewhat doughnut shaped with a number of flat surfaces on the outer rim and threads on the inner hole.
A metal block (solid nut) or sleeve having an internal thread made to assemble with the external thread on a bolt, screw, or other threaded part. It may be a fastening means, an adjusting means, a means for transmitting motion, or a means for transmitting power with large mechanical advantage and nonreversible motion.
Abbreviation for Input Shaft Speed to Vehicle Speed
Abbreviation for Noise, Vibration, and Harshness. Every vehicle has some degree of NVH. It is the task of the manufacturer to reduce them as much as possible. The comfort of vehicles can be compared based on their NVH. For example, some vehicles may have more noise but less vibration or harshness than another.
Abbreviation for Non Volatile Random Access Memory
Abbreviation for National Wooden Pallet and Container Association which is a national association with the goal of promoting the design, manufacturer, distribution, recycling and sale of pallets, containers and reels.
A self-locking nut with nylon insert. Also called nylon lock nut
A synthetic fiber which is stronger than vinyl. It can be used in sheet, fiber, or solid form.
A non-magnetic, non-metallic securing device made of a material that has a low dielectric constant and relatively high tensile strength, enabling it to resist high voltage at commercial frequencies. It can also operate at continuous temperatures as high as 121°C. Any temperatures above has an effect to oxidize material. Electric and electronic equipment manufacturers are finding many corrosion-resistant applications for this type of fastener.
A soft face hammer with a nylon face
Nylon lock nut
A self-locking nut with nylon insert. Also called nyloc nut
Nylon screw clutch release
A clutch release mechanism which uses a coarse, square threaded nylon screw for clutch disengagement.