- PR
-
- Abbreviation for Ply rating
- Abbreviation for Pressure Relief
- Pratt and Whitney key
- (P&W) A bar like a Flat key except the ends are oval shaped.
- Prechamber
- A small upper chamber in the cylinder head of a diesel engine, connected to the main combustion chamber by a narrow passage; fuel is injected into the prechamber (also called swirl chamber) where it is ignited before spreading to the main chamber.
- Precipitation hardened stainless steel
- Type 630 stainless, little used, expensive and not sold as commercial products, it combines corrosion resistance of 300 series stainless with high tensile strength of 400 series.
- Precipitation Hardening
- Hardening caused by the precipitation of a constituent from a supersaturated solid solution.
- Precipitation number
- A test to determine the volume of sediment in lubricating oil. While the oil filter will remove much sediment, some still remains, thus when the precipitation number exceeds a specified number, it should be replaced.
- Precision insert bearing
- A very accurately made replaceable type of bearing, it consists of an upper and lower shell, the shells are made of steel to which a friction type bearing material has been bonded, Connecting rod and Main bearings are generally of the precision insert type.
- Precision Machine Screws
- Slotted machine screws, milled from bar, cut thread, and are machined finished Class 3A fits.
- Pre-combustion chamber
-
- A small chamber located outside the combustion chamber of some cars in which a small amount of rich fuel-air mixture can be ignited to increase fuel efficiency and cut emissions. Found principally on diesel engines and stratified charge engines. Also called pre-chambers.
- A chamber in the cylinder head of some diesels where some fuel is injected, ignited, and partly burned before being forced out into the main chamber.
- Pre-combustion engine
- A diesel engine using Indirect injection. TheBritish term is Indirect injection engine
- Pre-compression chamber
- A chamber below the pistons in a two-stroke engine in which the fuel-oil mixture is initially compressed in order to enable more fresh charge to be fed into the cylinder
- Pre-converter vehicle
- A car built prior to the enforcement of emission control standards requiring a catalytic converter to be fitted to every new car
- Precured tread rubber
- Pre-cured rubber, usually of high density and available in various tread designs, is lined with cushion gum before applying to a buffed Casing using the Cold cap method of retreading. Recently it has been applied in some Hot cap molds employing a smooth matrix or other modifications.
- Pre-engaged starter
- A starter motor in which the solenoid-operated pinion engages with a flywheel ring gear before the full electric current flows; an overrunning clutch enables the pinion to freewheel before disengaging, once the engine has fired
- Preferential oxidation
- A reaction that oxidizes one chemical rather than another. In fuel cells, the reaction is used to preferentially oxidize carbon monoxide to carbon dioxide from the Reformate stream after the water-gas shift reactor and before the fuel cell. Same as selective oxidation.
- Pregnant roller skate
- Trucker slang for a Volkswagen Beetle as in 'Better get over, we got a pregnant roller skate trying to merge ahead.'
- Preheater system
- A cold starting aid for diesel engines, consisting of glow plugs, a glow-control unit, and a glow plug and starter switch, for preheating the combustion chamber or the intake air up to auto-ignition temperature
- Preheating
-
- Temperature to which a metal is heated before an operation is performed on the metal (welding, cutting, forming, etc.).
- The application of some heat prior to the later application of more heat, Cast iron is preheated to avoid Cracking when the welding process is started. A Coil (ignition) is preheated prior to testing.
See
- Preheating zone
- A section in Hot-wax flooding units, in which body shells are preheated to 60°C
- Preignition
- The fuel charge being ignited before the proper time. Sometimes causes pinging or Detonation. This is the combustion of the fuel-air mixture that is not a result of the spark plug's firing, but by high pressure, a flame, or a hot surface.
- Preload
- A bicycle suspension adjustment that usually involves modifying pressure or adjusting the elastomers to ensure that the suspension responds appropriately to the rider's weight
- Preloading
- Adjusting an antifriction bearing, Ball joint, or spring so that it is under mild pressure, this prevents bearing looseness under driving stress.
- Prelubricator
- A lubrication system consisting mainly of an electronically controlled pump that circulates pressurized engine oil to an engine's vital parts for about six seconds when the ignition is switched on prior to starting the engine; reduces friction during cold starts and prolongs engine life
- Premium Compact SUV
- An upscale sport utility vehicle of the Compact SUV size as represented by the following Acura RDX, BMW X3, Infiniti EX35, and Land Rover LR2.
- Premium gasoline
- Gasoline with a high amount of octane to give it an antiknock index (R+M/2) greater than 90. Includes both leaded premium gasoline as well as unleaded premium gasoline.
- Premium Large SUV
- Upscale model of a Large SUV such as the following.
Premium Large SUV Audi Q7 Cadillac Escalade Hummer H2 Infiniti QX56 Land Rover Range Rover Lexus LX 570 Lincoln Navigator Mercedes-Benz GL550-Class Toyota Land Cruiser
- Premium Midsize SUV
- An upscale Midsize SUV as seen in the following models
Premium Midsize SUV Buick Enclave Buick Rainier Cadillac SRX Chrysler Aspen Ford Explorer (Eddie Bauer Edition) Infiniti FX Jeep Grand Cherokees, Land Rover's LR3 Land Rover Range Rover Sport Lexus GX 470 Lexus RX Lexus RX300 Lincoln MKX Mercedes-Benz R-Class Porsche Cayenne Saab 9-7X Aero Volkswagen Touareg 2 Volvo XC90
- Premixing burner
- A power burner in which all or nearly all of the air for combustion is mixed with the gas as primary air.
- Pre-owned vehicle
- A Used vehicle. A term coined by car dealers to avoid the idea that a second-hand vehicle is used up (i.e., finished its usefulness).
- Pre-pump
- An electric fuel pump usually located in the fuel tank that keeps pressure in the fuel line prior to the main fuel pump to prevent vapor lock.
- Prescribed burning
- Skillful application of fire to natural fuels that allows confinement of the fire to a predetermined area and at the same time produces certain planned benefits.
- Pre-selector gearbox
- An arrangement that enables the driver to select a gear speed before he needs it and then depress the clutch pedal when he desires to use the selected gear.
- Preset station button
- A button for tuning a radio automatically to a preset frequency, i.e., one radio station can be allocated to each button
- Pressed steel
- Sheet steel made into curved sections by press forming. It is often used in the construction of the frame and forks
- Press fit
- An Interference fit. A fit so tight that an object must be removed with a Puller or a press.
- Pressure
-
- The force due to the weight of a substance exerted over the area the substance occupies. In metric measure, it is the force acting on each square metre. To calculate pressure, divide the force (in newtons) by the area (in square metres). It is measured in newtons per square metre (N/m²). In Imperial (U.S.) measure, it is measured in pounds per square inch (lb/in.²) (psi).
- Energy impact on a unit area; force or thrust on a surface.
- Force per unit area. As used in air conditioning systems, it refers to the refrigerant pressure, which is expressed in pounds per square inch (psi)
See- Absolute pressure
- Air pressure
- Allowable Working Pressure
- atmospheric pressure
- Atomizing pressure
- back pressure
- Barometric Pressure
- Boiler Pressure
- Boost pressure
- Brake mean effective pressure
- Cabin Differential Pressure
- Center of pressure
- clutch pressure plate
- Combustion pressure
- Control pressure
- Critical Pressure
- Dead-head Pressure
- Design Pressure
- Differential Pressure
- Discharge pressure
- Exhaust back pressure
- Extreme pressure lubricant
- Fuel pressure
- Gauge Pressure
- Governor pressure
- Head Pressure
- High pressure
- High pressure foaming
- High pressure relief valve
- Hydraulic Pressure
- Hydraulic pressure pump
- Indicated mean effective pressure
- Injection Pressure
- Injector Opening Pressure
- Leak-off Pressure
- Line pressure
- Low Head Pressure
- Low pressure indicator
- Low pressure tire
- Low-side Pressure
- Low-suction Pressure
- Lubricating pressure
- Manifold absolute pressure sensor
- Maximum Operating Pressure
- Mean effective pressure
- Mean indicated pressure
- Medium Pressure
- Modulator pressure
- Negative back pressure modulated valve
- Negative back pressure valve
- Oil-combination splash and pressure system
- Oil-full pressure system
- Oil pressure
- Oil pressure gauge
- Oil pressure sensor
- Oil pressure switch
- Oil pressure warning light
- Operating Pressure
- Partial Pressures
- Pressure bleeder
- Pressure cap
- Pressure relief valve
- Primary Pressure
- Ram pressure
- Rated pressure
- Reference Pressure
- Reid Vapor Pressure
- Residual pressure valve
- Solution pressure
- Static pressure
- Suction Pressure
- System Pressure
- Tire pressure
- Vacuum Pressure
- Vapor Pressure
- Zero Absolute Pressure
- Pressure accumulator
- A spherical pressure tank of about 10 mm diameter in an hydraulic brake booster. A diaphragm separates the pressure accumulator into two chambers, one contains pressurized nitrogen, the other contains hydraulic fluid supplied by the hydraulic pump; pressure inside the accumulator is in the order of 60 bar
- Pressure bleeder
-
- A device that forces brake fluid under pressure, into the master cylinder so that by opening the bleeder screws at the wheel cylinders, all air will be removed from the brake system.
- A container with a brake fluid and air compartment separated by a diaphragm. Used with adapters to supply a constant, clean pressurized source of brake fluid for bleeding.
- Pressure buildup
- As a tire heats up as it travels on the road, the air inside the tire expands and thus increases the air pressure. Any increase exceeding 15% above starting cold pressure should be investigated. The practice of Bleeding the excess or hot pressure should be avoided.
- Pressure burner
- A burner which is supplied with a gas-air mixture under pressure, usually from 0.5 to 14.0 inches water column (1/8 to 3.5kPa) and occasionally higher.
- Pressure cap
- A special cap for the radiator, it holds a predetermined amount of pressure on the water in the cooling system, this enables the water to run hotter without boiling. In this way, the engine can operate at a higher and a more efficient temperature without danger of overheating. The cap also has a vacuum valve that lets air into the cooling system if the pressure falls too low to prevent outside air pressure from causing a partial collapse of the radiator.
Pressure cap
- Pressure differential sensor
- A detection device that reads pressure changes in the intake manifold in relation to barometric pressure. Also called a manifold pressure sensor, manifold vacuum sensor, or vacuum sensor
- Pressure differential switch
- A hydraulic pressure-operated switch (often included in a combination valve) which activates the brake failure warning light when one of the brake circuits (in a dual-circuit system) falls due to a system leak and associated pressure drop
- Pressure differential valve
-
- Senses unbalanced hydraulic pressure between two halves of the split brake system
- A spool-type valve used in dual brake systems to detect any difference in pressure between the systems. Its motion usually operates a switch that sends current to a warning lamp on the instrument panel.
- Pressure differential warning switch
- A component of the brake hydraulic system that warns the driver of a failure in one of the circuits
- Pressure drop
-
- The difference in pressure between two points in the system, usually caused by a restriction device. Specifically the difference in pressure where fuel metering occurs. In electronic injection system, this is the difference between fuel system pressure and intake manifold pressure. In Bosch CIS, it is the difference between system pressure inside the control plunger and the pressure outside the slits, in the upper-chamber of the differential-pressure valves
- Pressure difference at two ends of a circuit, or part of a circuit; the two sides of a filter.
- Pressure-feed spray gun
- A type of spray gun with a separate paint container (pressure-feed tank). It is used mostly for spraying highly viscous materials such as spray putty
- Pressure gauge
- Instrument for measuring the pressure exerted by the contents on its container. Reading in pounds per square inch (psi) above atmospheric pressure.
- Pressure, head
- Force caused by the weight of a column or body of fluids. Expressed in feet, inches, or psi.
- Pressure-heat diagram
- Graph of refrigerant pressure. heat and temperature properties. (Mollier's diagram).
- Pressure limiter
- Device which remains closed until a certain pressure is reached, then opens and releases fluid to another part of system or breaks an electric circuit.
- Pressure limiting valve
- A British term for a Proportioning valve
- Pressure lubrication
-
- Forced-feed lubrication.
- Lubrication system with crankcase scavenging. Fresh oil is supplied from a separate container and lubricates the engine components as it passes through the crankcase. The oil is ignited along with the air/fuel mixture. With this system, it is no longer necessary to add oil to the fuel when filling up
- Pressure motor control
-
- Device which opens and closes an electrical circuit as pressures change.
- High- or low-pressure control connected into the electrical circuit and used to start and stop motor. It is activated by demand for refrigeration or for safety.
- Pressure-operated altitude valve
- (poa) Device which maintains a constant low-side pressure, independent of altitude of operation.
- Pressure plate
-
- The plate that carries the brake pad in a disc brake. Also called Backplate.
- The part of the clutch assembly which is pressed against the clutch plate by the clutch springs to transmit the drive.
- Pressure regulating valve
-
- Any valve which maintains pressure at or under a certain pressure; specifically the pressure relief valve of the oil pump.
- In a continuous injection system, part of the fuel distributor, consisting basically of a spring-loaded steel diaphragm which serves to keep the pressure drop across the metering ports at a constant 0.1 bar
- Pressure regulator
-
- A spring-loaded diaphragm-type pressure-relief valve which governs the pressure of the fuel delivered to the fuel injectors by the fuel pump and returning the excess to the tank.
- A device placed in a gas line for reducing, controlling and maintaining the pressure in that portion of the piping system downstream of the device.
- Pressure regulator, evaporator
- Automatic pressure regulating valve mounted in suction line between evaporator outlet and compressor inlet. Purpose is to maintain a predetermined pressure and temperature in the evaporator.
- Pressure relief
- What you must do to all fuel injection system before cracking a line and opening up the system
- Pressure relief valve
-
- A one-way valve designed to open at a specific pressure to prevent pressures in the system from exceeding certain limits. In an engine's lubrication system, a pressure-relief valve opens to relieve excessive pressure that the oil pump might develop.
- A valve which automatically opens and closes a relief vent, depending on whether the pressure is above or below a predetermined value.
- Pressure ridge
- A work-hardened edge of a damaged panel area that will often remain, even after the area has been smoothed with hammer and dolly; it must then be dressed with hammer and body spoon
- Pressure sensing line
- A tube that connects the remote bulb to the expansion valve. Also called Capillary tube
- Pressure sensing switch
- Device, used on some late model GM and Ford vehicle, which cycles compressor operation in accordance with pressure changes sensed at the accumulator
- Pressure sensitive adhesive
- Type of adhesive that retains its tack or stickiness even after complete release of the solvent
- Pressure tap
- Also called a Fuel-injection system test port
- Pressure vessel
- Containers for the containment of pressure either internal or external. This pressure may be obtained from an external source, or by the application of heat from a direct or indirect source, or by any combination of them.
- Pressure water valve
- Device used to control water flow. It is responsive to head pressure of refrigerating system.
- Pressure wave
- Pulsations or oscillations in the induction and exhaust systems caused by the opening and closing of the valves
- Pressure wave supercharger
- A supercharger using the pressure waves created by the expanding exhaust gases to compress the inlet charge. Also called Comprex supercharger
- Presta valve
- A bicycle tube valve whose stem has a small nut on top, which must be loosened during inflation, instead of a spring such as is found on the Schrader valve.
Presta valve
- Pretensioner
- A device that retracts the seat belt to tighten or take up slack in the wearer's belt. When a collision occurs or when brakes are applied, a seat belt with a pretensioner detects the stopping action and tightens the belt before the wearer is propelled forward. This holds the occupant more securely in the seat.
- Preunit
- An engine and gearbox that are not built together in the same casing. Preunit construction was common on earlier motorcycles
- Pre-wetting
- The process of applying liquids to salt (before spreading salt on paved roads) to accelerate the ice melting process and prevent salt from bouncing off the road surface.
- Primary air
- Air introduced into a burner at the mixer head, which mixes with the gas before reaching the port(s).
- Primary air inlet
- One or more openings through which Primary air is admitted into a burner.
- Primary and secondary roads
- Primary roads are those designated by an agency to have a higher priority for plowing and sanding; secondary roads are those designated to have lower priority
- Primary battery
- A non-rechargeable battery consisting of one or more primary cells, used e.g., in portable radio receivers. Opposite to Secondary battery or Storage battery
- Primary brake shoe
- The brake shoe that is first to press against the Brake drum. The other shoe is the secondary shoe. When both shoes are pressing against the drum, the amplification of forces is called servo action.
- Primary catalytic converter
- A small converter positioned close to the engine which quickly achieves the necessary operating temperature to reduce exhaust emissions during the warm-up period
- Primary cell
- An electric cell that converts chemical energy into electrical energy in an irreversible process unlike a secondary cell, it cannot be recharged
- Primary circuit
- The low voltage (6 or 12 volts) path of the ignition system which goes from the Positive pole of the battery to the Primary windings of the coil, through the breaker points, and into the ground which leads back to the Negative pole of the battery.
- Primary coil
- A tube-and-fin circular coil that contains a water glycol solution which surrounds the ignitor and burner. This coil is used in a water glycol gas forced-air furnace.
- Primary compression
- A term that is used in two-stroke engines. Primary compression takes place in the crankcase and is then pushed up into the combustion chamber where Secondary compression takes place as the piston squeezes the mixture. If the crankcase seals are poor, primary compression will be reduced resulting in reduced Secondary compression so that it may be difficult to start the engine.
- Primary compression ratio
- The degree of compression achieved in the crankcase area below the piston of a two-stroke engine when the piston moves down and compresses the mixture supplied into the crankcase
- Primary forward brake shoe
- The brake shoe that is installed facing the front of the vehicle, it will be a self-energizing shoe.
- Primary fuels
- Fuels that can be used continuously. They can sustain the boiler sufficiently for the production of electricity.
- Primary ignition
- The low-voltage part of the ignition circuit, such as part of the ignition coil wiring, the pickup, electronic ignition module, and ECM. Compare Secondary ignition
- Primary piston
-
- The main piston in a tandem master cylinder
- In a dual or tandem master cylinder, the piston against which the brake pedal or power booster pushrod bears.
- Primary pull-off diaphragm
- Device that partially opens the choke when vacuum develops (i.e., when the engine starts), allowing more air to pass through the carburetor, thinning out the excessively rich idle mixture
- Primary pump
- An engine-driven oil pump feeding pressurized oil to the transmission and hydraulic control system
- Primary recovery
- The crude oil or natural gas recovered by any method that may be employed to produce them where the fluid enters the well bore by the action of natural reservoir pressure (energy or gravity).
- Primary Safety control
- A control responsive directly to flame properties; sensing the presence of flame and causing fuel to be shut off in the event of ignition or flame failure requiring manual reset.
- Primary shoe
-
- The shoe of a brake drum system which pivots outwards into the approaching drum. TheBritish term is Leading shoe
- The shoe in a duo-servo drum brake that transfers part of its braking force to the secondary shoe
- The shoe in a servo brake that transfers a portion of its stopping power to the secondary shoe. The primary shoe provides nearly 30% of the total stopping power.
- Primary structure component
- Any structural component which, if it collapsed, could make the car uncontrollable or would seriously reduce occupant safety in a crash
- Primary terminal
- The clip found inside the distributor which allows electric current to pass from the points to the condenser and provides the Insulation to keep the current from contacting other metal parts.
- Primary valve
- The valve which controls the Primary V-pulley
- Primary V-pulley
- (CYT) The pulley which is driven by the engine via a clutch; one of its halves can be slid hydraulically, thus varying the diameter of the steel thrust belt track and changing the transmission ratio
- Primary winding
- The low voltage (6 or 12 volt) windings in ignition coil, the primary winding is heavy wire; Secondary winding uses fine wire.
- Primary windings
- The low voltage (6 or 12 volt) windings in ignition coil, the primary winding is heavy wire; secondary winding uses fine wire.
- Primary wires
- The wiring which serves the low voltage part of the ignition system. Wiring from battery to switch, Resistor, ignition coil, distributor points.
- Prime
-
- To paint bare metal with Primer to prevent rusting. A second color (often different from the prime color) is painted over the primer.
- Pronounced PREEM, a stage in a bicycle race.
- To fill a machine (e.g., a pump) with the necessary fluid before starting, in order to improve its sealing qualities.
- To put fuel in the float chamber of a carburetor to ease the starting of an engine
- Prime coat
- A Primer or surfacer applied to the old paint or bare metal before the Finish coat is applied.
- Prime mover
- The engine, turbine, water wheel, or similar machine that drives an electric generator; or, for reporting purposes, a device that converts energy to electricity directly (e.g., photovoltaic solar and fuel cells).
- Primer
- The surfacer that acts as a bond between the bare metal surface or old paint and the color Coat and designed to give rust protection.
- Primer bath
- A container filled with Primer into which a metal object is submerged. This painting procedure is faster than spray painting and will cover better. The disadvantage is that a lot of primer is required and the metal must be bare of anything else (i.e., glass, rubber, cloth)
- Primer surfacer
- The material for the resilient coating underneath the top paint coat which provides corrosion protection, protects the paint system from chipping caused by gravel, provides a smooth surface for the top paint coat, and serves as an adhesion promoter. A primer that contains a lot of solid material to fill small imperfections in the substrate (primer-surfacer must be sanded before applying paint over them)
- Princess
- An automobile manufactured by British-Leyland
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Princess
- Printed circuit
- An electrical circuit made by connecting the units with electrically conductive lines printed on a panel, this eliminates actual wire and the task of connecting it.
- Printed circuit board
- (pcb) A thin plastic insulating board on one or both sides of which the components and connections of an electronic circuit are formed by etching in a metallic coating or electrodeposition
- Priority crossing
- See Scramble crosswalk
- Private Carrier
- A business which operates trucks primarily for the purpose of transporting its own products and raw materials. The principle business activity of a private carrier is not transportation. Compare For-Hire Carrier.
- Private fueling facility
- A fueling facility which normally services only fleets and is not open to the general public.
- Private Street
- A privately owned and maintained access provided for by a tract, easement or other legal means, typically serving three or more potential dwelling units.
- A model of car produced by the Chevrolet division of General Motors from 1998 to 2002
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Prizm
- PRND
- Abbreviation for the order in which an automatic transmission is displayed to the driver and stands for Park, Reverse, neutral, and Drive. Sometimes, two or more drive positions will be displayed as D1 and D2.
- PRNDL
- Abbreviation for the order in which an automatic transmission is displayed to the driver and stands for Park, Reverse, neutral, Drive, and Low. Sometimes, the Low may be divided into 3, 2, 1.
- Probe
-
- A pointed tool, like an icepick. It is used to determine the extent of injuries during the tire inspection.
- An Awl.
- A measuring sensor, usually long and thin to gain access to narrow cavities. See
- A model of automobile manufactured by Ford
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Ford Probe
- Process
- See
- Basic Process
- Batch Process
- Bessemer Process
- Betts Process
- Bredigs Arc Process
- Cailletets Process
- Catalan Process
- CBR process
- Electrolytic Process
- Electrochemical Process
- Electrodeposition Process
- Jet process
- Lost-foam casting process
- Plasma spray process
- Pulse Combustion Process
- Reverse process
- Sendzimir process
- VERTAC-process
- Process Annealing
- Heating a ferrous alloy to a temperature close to, but below, the lower limit of the transformation range and then cooling, in order to soften the alloy for further cold working.
- Process cooling and refrigeration
- The direct process end use in which energy is used to lower the temperature of substances involved in the manufacturing process. Examples include freezing processed meats for later sale in the food industry and lowering the temperature of chemical feedstocks below ambient temperature for use in reactions in the chemical industries. Not included are uses such as air-conditioning for personal comfort and cafeteria refrigeration.
- Process fuel
- All energy consumed in the acquisition, processing, and transportation of energy. Quantifiable process fuel includes three categories: natural gas lease and plant operations, natural gas pipeline operations, and oil refinery operations.
- Processing gain
- The volumetric amount by which total output is greater than input for a given period of time. This difference is due to the processing of crude oil into products which, in total, have a lower specific gravity than the crude oil processed.
- Processing loss
- The volumetric amount by which total refinery output is less than input for a given period of time. This difference is due to the processing of crude oil into products which, in total, have a higher specific gravity than the crude oil processed.
- Procon-ten
- A safety system developed by Audi which makes use of the relative displacement of the engine during a frontal collision; steel cables pull the steering wheel away from the driver and increase the seat belt tension
- Product carrier
- A tanker used to carry refined oil products. Normally four different grades of oil can be handled simultaneously.
- Production car
- A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called production model.
- Production engineering
- Planning and control of the mechanical means of changing the shape, condition of materials toward greater effectiveness and value.
- Production line
- A system of assembly in which the parts of an end product are transported by a conveyor past a number of sites where the parts are modified without stopping the conveyor
- Production model
- A vehicle manufactured by a mass-production process. A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called production car.
- Production motorcycle
- Bikes manufacturer produce to sell to the general public rather than bikes built specifically for racers
- Production plant liquids
- The volume of liquids removed from natural gas in natural gas processing plants or cycling plants during the year.
- Production retread shop
- A shop which schedules its production not on the basis of day-to-day orders but rather on long runs of purchased Tire casings in order to secure the lowest cost per unit.
- Production vehicle
- A vehicle manufactured by a mass-production process. A vehicle model that has been assembled for sale to the general public as opposed to a concept vehicle that is not available to be purchased. Also called production model.
- Product line
- A series of different products made by the same company which form a group (such as different models of cars)
- Product planning
- A function whereby an enterprise is responsible for the efficient, planning, scheduling and coordination of production activities.
- Product range
- A series of different products made by the same company which form a group (such as different models of cars)
- Professional drivers
- Drivers whose main income is from driving, such as bus, coach and haulage drivers
- Profile depth
- See
- Tread depth
- Compare Aspect ratio
- Profile ignition pickup
- (PIP) a Hall Effect vane switch that furnishes crankshaft position data to the Ford EEC-IV processor
- Program cars
- Automobiles sold by manufacturers for fleet use. Usually applies to very large fleets, such as those of car rental companies.
- Program comparison and identification
- (PCI) A system that identifies a radio station and compares stations to find the station which offers the strongest signal
- Programmable controller
- A digitally operating electronic system designed for use in an environment, which uses a programmable memory for the internal storage of user-oriented instructions for implementing specific functions such as logic, sequencing, timing, counting and arithmetic to control, through digital or analog inputs and outputs, various types of processes or machines.
- Programmable read only memory
-
- (PROM) An electronic component which can be specifically programmed to the design of each car model to control the M/C solenoid. Plugs into the Electronic Control Module (ECM). Also called an Engine calibration unit
- A non-volatile memory that stores information permanently. This type of memory cannot be written to. Once programmed, it cannot be altered.
- Programmed Fuel Injection
- (PGM-FI) Honda's fuel injection system for the Accord, Civic, Civic CRX, and Prelude
- Programmer
- The module that controls blower speed, the air mix door, vacuum diaphragms and other devices in a system equipped with automatic temperature control
- Program objectives
- A consensus of what has been determined to be the most marketable product for a given model year.
- Progressive linkage
- A carburetor linkage designed to open the Throttle valves of multiple carburetors. It opens one to start with and when a certain opening point is reached, it will start to open the others.
- Progressively wound valve spring
- A valve spring with variable spacing between its coils which helps to improve responsiveness and thus to reduce the load on the valve train
- Progressive rate spring
- A spring with an increasing spring constant. For example, if the first inch of spring motion requires 100 pounds of force, the second inch would require more than an additional 100 pounds, and the third inch would require still more. Progressive-rate springs become stiffer as they are compressed, unlike single-rate springs, which have a fixed spring rate.
- Progressive suspension
- A system in which the suspension stiffness changes depending on the amount of change required. On light bumps, the suspension is soft; but on greater bumps, the suspension is stiff.
- Progressive transmission
- An older version of a manual transmission. When you wanted to go from Low gear to the highest gear, you had to go through all the gears in between. Likewise when you wanted to go from the highest gear to the lowest, you had to proceed through all the Intermediate gears.
- Progressive valve spring
- A valve spring with variable spacing between its coils which helps to improve responsiveness and thus to reduce the load on the valve train
- Projected spark position
- The amount the spark plug gap projects into the combustion chamber 1 mm for the slightly projected spark position in older engines and 3 mm for the normally projected spark position in modern engines
- PROM
- Abbreviation for ProgrammableRead Only Memory. PROM contains permanent information about how components should perform under various operating conditions
- Promoter
- A substance embedded in the washcoat on catalyst substrates that serves to enhance catalytic efficiency
- Promptness
- The speed of action of a governor which depends upon its power relative to the work it must do. The greater the power, the shorter the time required to overcome the resistances.
- PRO Number
-
- A number assigned to a shipment by the carrier for tracking purposes.
- Any progressive or serial number applied for identification to freight bills, bills of lading, etc.
- The nine-digit number used to identify a freight bill, and which corresponds to a scannable bar code. Same as freight bill number.
- Prony brake
-
- A device using a friction brake to measure the horsepower output of an engine.
- A simple mechanical device, normally made of wood with an adjustable leather strap, that is used to test for the torque output of an electric motor. The prony brake loads the motor and a spring scale attached to it gives a relatively accurate measurement of torque.
- Proof load
- A test load that a fastener must undergo without showing significant deformation. It is usually 90% of yield strength.
- Propane
- (C3H8)
- A colorless, flammable gas which is a Petroleum product, similar to and often mixed with Butane. It is useful as an engine fuel or for cooking and heating. In Canada this is the term used for LPG.
- A flammable, heavier-than-air gas used in the Halide torch leak detector
- Volatile hydrocarbon used as a fuel or as a refrigerant.
- Propane air
- A mixture of Propane and air resulting in a gaseous fuel suitable for pipeline distribution.
- Propane MD-5
- A special grade of liquefied petroleum gas composed of a minimum of 90 percent liquid volume of propane (C3H8) and a maximum of 5 percent liquid volume of Propylene (C3H6).
- Propeller
- The impeller of a pump, characterized by a small number of blades of double curvature; propellers are generally axial-flow impellers, seldom mixed-flow ones.
- Propeller pump
- The impeller of a pump, characterized by a small number of blades of double curvature; propellers are generally axial-flow impellers, seldom mixed-flow ones
- Propeller shaft
- British term for driveshaft. The shaft connecting the transmission Output shaft to the differential pinion shaft.
- Propelling power
- The force with which a vehicle moves; the pulling force; depends not only on engine power and torque, but also on the amount of friction between driving wheels and road surface
- Proper proportion of air and fuel
- One of the essential factors in a Combustion engine (Fuel, Air, Proper proportion of mixture, compression, timing, spark).
- Proper ventilation
- In general, the dilution of a flammable gas/vapor with air to a point safely below its lower explosive limit (LEL). As applied to this standard, a sufficient or adequate supply of fresh air and proper exhaust to outdoors or to a safe location with a sufficiently-vigorous and properly distributed air circulation to ensure that the flammable gas/vapor concentration in all parts of the enclosure will be below 25 percent of the LEL at all times.
- Proportioning
- The act of distributing something (e.g., brake fluid) to several components in equal measures.
- Proportioning valve
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- Any valve which limits pressure in a system, e.g., in a hydraulic circuit, in automatic transmissions, in pneumatic suspension systems, etc.
- The valve used in the rear brake line of some cars with front disc and rear drum brakes. When braking gently, pressure is about equal front and rear; as pedal pressure is increased, the limiting valve controls and finally limits pressure to the rear wheels to prevent rear wheel lockup during heavy braking. The British term for proportioning valve is pressure limiting valve.
- A hydraulic valve that reduces pressure to the rear wheel to obtain balanced braking.
- A hydraulic control valve located in the circuit to the rear wheels which limits the amount of pressure to the rear brakes to prevent wheel lock-up during panic stops
- Propshaft
- Abbreviation for Propeller shaft.
- Prop shaft
- Abbreviation for Propeller shaft. See
- Propulsive power
- The force with which a vehicle moves; the pulling force; depends not only on engine power and torque, but also on the amount of friction between driving wheels and road surface
- Propylene
- (C3H6) An Olefinic hydrocarbon recovered from refinery processes or petrochemical processes.
- Prospector's pick
- A tool with a long handle (usually made of wood) to which a long curved piece of iron has been attached. At one end of the iron is a point while a blade shape is at the other end.
- Prost, Alain
- Alain Prost of France is a four-time World Driving Champion. He is the only French Grand Prix driver to win the World Championship in the modern era (1951 through the present). He has won more races than any other driver in Grand Prix racing history. And his 51 wins are a record that will likely stand for a long time.
- Protector, circuit
- Electrical device which will open an electrical circuit if excessive electrical conditions occur.
- Protector washer
- A filter disc between the primary piston and primary seal which supports and protects the primary seal when the brake system is under pressure
- Proton exchange membrane
- (PEM) The separating layer in a PEM fuel cell that acts as an electrolyte (which is proton conducting) as well as a barrier film separating the hydrogen-rich feed in the cathode compartment of the cell from the oxygen-rich anode side.
- Proton exchange membrane fuel cell
- (PEMFC or PEFC) A type of acid based fuel cell in which the exchange of protons (H+) from the anode to the cathode is achieved by a solid, aqueous membrane impregnated with an appropriate acid. The electrolyte is a called a proton-exchange membrane (PEM). The fuel cells typically run at low temperatures (less than 100°C) and low pressures (less than 5 atm).
- Proud
- Something that projects up slightly from the surrounding surface. Something not Flush. Also called Standing proud or Stand proud