- Mean effective pressure
- (MEP)
- The average pressure of the burning fuel on the Power stroke subtracted by the average pressure on the other three strokes. Pressure is in pounds per square inch.
- Average pressure on a surface when a changing pressure condition exists.
- Mean indicated pressure
- A mathematical value that indicates the relation between the effective area of the work diagram of the two-stroke engine and the movement of the piston
- Mean time to repair
- (MTR) The time interval (hours) that may be expected to return failed equipment to proper operation.
- Mechanical advantage
- The ratio of the force exerted to the force applied. A manual brake pedal may have a mechanical advantage, or pedal ratio of 5 to 1.
- Mechanical brakes
- Service brakes that are actuated by a mechanical Linkage such as rods or cables (rather than Hydraulic lines) connecting the brakes to the Brake pedal. The Parking brake on most vehicles is mechanical.
- Mechanical efficiency
- An engine's rating as to how much of the PotentialHorsepower is wasted through Friction within the moving parts of the engine. The ratio between the Indicated horsepower and the Brake horsepower of an engine.
- Mechanical face seal
- A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)
- Mechanical fade
- Brake fade caused by heat expansion of the brake drum away from the brake linings. Not a problem with disc brakes.
- Mechanical-hydraulic booster
- A power booster that uses hydraulic pressure from the power steering pump to increase brake application force.
- Mechanical Interrupter
- A device which provides for mechanical closure of the fuel flow to the main burner by positive means such as an applied manual force through a linkage, lever handle, spring or similar mechanical means.
- Mechanical plating
- A deposition of zinc on another material by a cold-peening process, such as tumbling
- Mechanical Properties
- Those properties of a material that reveal the elastic and inelastic reaction when force is applied, or that involve the relationship between stress and strain; for example, the modulus of elasticity, tensile strength and fatigue limit.
- Mechanical protection
- Where clogging materials are present in severe proportions, the air gap of Open enclosure electric motors may become clogged. Therefore, the recommendation is a Totally enclosed motor housing to obtain mechanical protection from the elements.
- Mechanical seal
- A shaft seal consisting of two highly polished mating surfaces, one surface being connected to the shaft (rotating element) and the other to the casing (stationary element)
- Mechanical stress
- A force acting across a unit area in solid materials in resisting the separation, compacting, or sliding that tends to be induced by external forces
- Mechanical surface treatment
- A production of a dull or rough surface or a decorative finish by grinding, brushing, polishing, or abrasive blasting
- Mechanic installed market
- (MIL) Vehicle maintenance and repair conducted by a mechanic/professional at a service outlet.
- Mechanic's elbow
- A shallow dent in body panels, usually on the top of a fender near the engine compartment; caused when leaning over into the engine compartment and supporting the body with elbows on the fender
- Mechanics lien
- When you take your vehicle to a shop to be repaired and you fail to pay your repair bill, the repair shop has a Lien on your vehicle and can confiscate and sell your vehicle to pay for the work on your vehicle.
- MECS
-
- Acronym for Mazda Electronic Control System
- Acronym for Manufacturing Energy Consumption Survey
- Median space
- A gap provided in the center of a dual carriageway to allow vehicles to cross through or turn onto another road
- Medium carbon steel
- A type of carbon steel used extensively for sheet metal screws and grade 2 hex head bright cap screws.
- Medium pressure
- For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch.
- Medium-temperature collector
- A collector designed to operate in the temperature range of 60°C to 82°C, but that can also operate at a temperature as low as 43°C. The collector typically consists of a metal frame, metal absorption panels with integral flow channels (attached tubing for liquid collectors or integral ducting for air collectors), and glazing and insulation on the sides and back.
- Megger
- A portable instrument used to measure insulation resistance. It consists of a hand-driven DC generator and a direct reading ohm meter.
- Member
- A general term that refers mainly to the side rails and crossmembers but also to any structural hollow-section part on a vehicle.
- Member of the gear train
- Sun gear, internal gear, and planet carrier are the members of a planetary gear train
- Membrane
- The separating layer in a fuel cell that acts as electrolyte (a ion-exchanger) as well as a barrier film separating the gases in the anode and cathode compartments of the fuel cell.
- Membrane electrode assembly
- (MEA). Structure consisting of a proton-exchange membrane with surfaces coated with Catalyst/carbon/binder layers and sandwiched by two microporous conductive layers (which function as the gas diffusion layers and current collectors).
- Memory button
- A button which operates the position of electric seats, mirrors, etc. and which stores the requirements of a particular driver in its memory
- MEP
- Acronym for Mean effective pressure.
- Mercaptan
- An organic chemical compound that has a sulfur like odor that is added to natural gas before distribution to the consumer, to give it a distinct, unpleasant odor (smells like rotten eggs). This serves as a safety device by allowing it to be detected in the atmosphere, in cases where leaks occur.
- Mercedes
-
A vehicle brand of which all 1925-1948 models with required application are classic cars.
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Mercedes
- Mercedes-Benz
-
A German vehicle brand which began in 1871, of which all 230 and up, and K, S, SS, SSK, SSKL, Grosser and Mannheim models with required application are classic cars. The following cars are milestone cars:
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Mercedes-Benz- 1955-61 190 SL model
- 1951-54 220A Coupe and Convertible
- 1956-65 220S/220SE Coupe and Convertible
- 1963-67 230SL Coupe and Convertible
- 1965-67 250SE Coupe and Convertible
- 1965-67 250 SL models
- 1969-70 280 SL models
- 1965-67 300 SE Coupe and Convertible
- 1952-64 300 S, SL, SE, 300 Coupe and Convertible
- 1964 600 model
- 1965-70 SWB-LWB 600 models
- Mercer
- A vehicle brand of which the 1925-1948 models are classic cars.
- Mercoid bulb
- Electrical circuit switch which uses a small quantity of mercury in a sealed glass tube to make or break electrical contact with terminals within the tube.
- Mercosur
- The southern zone common market of Argentina, Brazil, Paraguay, and Uruguay. Mercosur enacted a common external tariff on January 1, 1995 for almost 85 percent of tariff items of the four countries; most trade among members will be duty-free.
- Mercury
-
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Ford's Mercury-
A vehicle brand of the Ford Motor Company which began
in 1939 and of which the 1967-68 Cougar XR-7 models are
milestone cars. The 1946 Sportsman is a
milestone car. The 1954-55 Sun Valley models
are milestone cars. It includes the following:
- Capri (1991-94)
- Cougar (1967-2002)
- Grand Marquis (1979-current)
- Marauder (2003-04)
- Mariner (2005-08)
- Milan (2006-07)
- Montego (2005-07)
- Monterey (2004-07)
- Mountaineer (1997-2008)
- Mystique (1995-2000)
- Sable (1986-2005, 2008-current)
- Topaz (1984-94)
- Tracer (1988-99)
- Villager (1993-2002)
- A model of car produced by the Chevrolet division of General Motors in 1933.
-
A vehicle brand of the Ford Motor Company which began
in 1939 and of which the 1967-68 Cougar XR-7 models are
milestone cars. The 1946 Sportsman is a
milestone car. The 1954-55 Sun Valley models
are milestone cars. It includes the following:
- Mercury barometer
- A device used to determine atmospheric pressure by observing the height of a column of mercury
- Mercury switch
- Safety switch to prevent erroneous deployment of the air bag. Due to ecological problems associated with mercury in automobile waste, mercury switches are being replaced by suspended-mass switches, e.g., a Hamlin switch
- Mercury vapor lamp
- A high-intensity discharge lamp that uses mercury as the primary light-producing element. Includes clear, phosphor coated, and self-ballasted lamps.
- Merging
- The action of a vehicle which enters the highway at approximately the same speed as the highway traffic and moves between the other vehicles to become part of the highway traffic
- Merkur
-
A model of automobile manufactured by Ford of Europe which included Scorpio (1988-89) and XR4Ti (1985-89)
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Merkur
- Mesh
- To engage, especially gears. The opposite is Disengage.
Also see
- Meshing spring
- A component of a pre-engaged starter which ensures that the shift lever will move to its final position and that the starter current will be switched on in case of tooth abutment
- Message center
- Usually a multifunctional display of a diagnostic system. A typical messages are NORMAL, DOOR AJAR, TAILGATE OPEN, LAMP OUT, WASHER FLUID LOW, etc.
- Met
- Term applied to the heat release from a human at rest. It equals 1 8.4 Btu/sq. ft./hr. (50 kcal/m2/hr or 58 W/m2).
- Metacenter
- The intersection point of a vertical line drawn through the line of buoyancy of a slightly listed vessel which intersects the centerline plane
- Metacentric height
- The distance from the metacenter to the center of gravity of a ship. If the center of gravity is below the metacenter the vessel is stable
- Metal cargo
- Truck contents which include metal pipe, coils, metal fencing, ingots, steel plates, corrugated tin, and similar processed metal cargoes.
- Metal catalyst
- A catalyst whose active phase is supported by a metal substrate, i.e., sheet steel. Compare Metal monolith
- Metal conditioner
- An acid-based metal cleaner that removes rust and corrosion from bare metal, etches it for better adhesion and forms a corrosion resistant film
- Metal fatigue
- A crystallizing of the metal due to vibration, twisting, bending, etc. The unit will eventually break. Bending a piece of wire back and forth to break it is a good example of metal fatigue.
Also see
- Metal forming
- Solid metal and molten metal process such as casting, forging, Stamping, and machining.
- Metal halide lamp
- A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements. These lights have the best Color Rendition Index (CRI) of the high-intensity discharge lamps. They can be used for commercial interior lighting or for stadium lights.
- Metallic drive screw
- A British term for a Self-tapping screw
- Metallic finish
- A type of paint in which tiny flecks of shiny metal has been added in order to give a sparkle effect.
- Metallic friction material
- A sintered friction material formulated with metallic or metallic-ceramic materials.
- Metallic lining
- semi-metallic lining
- Metallic paint
- A Finish paint colors that contain both Pigment and small metallic flakes which reflect light. The opposite is solid paint. The flakes are often of different sizes. When the surface is viewed from different angles, the color shade seems to vary, since the flakes are all oriented at different angles in the paint and consequently reflect the light differently. Japanese motorcycles used a different size of flakes than was common in the USA. As a result, repainted tanks in the USA did not have the same look.
- Metallize
- To coat or impregnate a metal or non-metal surface with metal, as by metal spraying or by vacuum evaporation
- Metallographic examination
- A test to determine the structural composition of a metal as shown at low and high magnification and by X-ray diffraction methods. Tests of this type include macro-examination, micro-examination, and X-ray diffraction analysis
- Metal shafts
- These are used to attach the connecting rods to the crankshaft. Also called eccentric journals
- Metal spraying
- A coating of surfaces with droplets of molten metal or alloy by using a compressed gas stream
- Metal support
- A thin corrugated strips of steel alloy rolled up into a tight coil as a support for the catalyst in a catalytic converter.
Also see
- Meter
-
- A device for measuring the quantity of a substance passing through it.
- To measure with a meter.
- To supply at a measured rate.
- A distance of about a yard (actually a little over 39.37"). Also spelled metre.
Also see- Air flow meter
- Air Mass Meter
- Air Meter
- Ampere-hour Meter
- Ampere-turns Per Meter
- Bouncing-pin Detonation Meter
- CO meter
- Demand Meter
- Dwell meter
- Dynamic Timing Meter
- Hot-wire airflow meter
- L-jetronic air flow meter
- Mass airflow meter
- Newton metre
- Parking meter
- Smoke meter
- Trip meter
- Vane Air-flow Meter
- Metering jet
- A small hole or orifice used to control the flow of Gasoline in various parts of the Carburetor.
- Metering rod
- A thin, movable rod which varies the opening area in a Carburetor jet. As the rod is raised it permits more fuel to enter the jet.
- Metering signal
- A (relative) vacuum signal generated by the pressure differential that occurs at the venturi. The strength of the metering signal determines how much fuel is pulled from the main circuit into the venturi. The smaller the venturi the greater the pressure drop and the stronger the metering signal; the larger the venturi, the smaller the pressure drop and the weaker the metering signal
- Metering slits
- In Bosch CIS, the narrow slits in the control-plunger barrel of the fuel distributor. Fuel flows through the slits in accordance with the lift of the control plunger and the pressure drop at the slits
- Metering unit
- A unit which regulates the quantity of fuel injected in the K-jetronic system. A lever connected to the sensor plate raises or lowers a stepped control plunger in the metering unit. The position of the control plunger relative to the metering ports in the metering unit varies the flow of fuel to the fuel injectors
- Metering valve
-
- A valve positioned in the hydraulic line to the front brakes, on some cars with front disc and rear drum brakes. It prevents the disc brakes from applying until after the rear brake linings contact the drum. The metering valve closes off pressure to the front disc brakes until a specified pressure level is generated in the master cylinder. This allows pressure in the rear brake circuit to overcome return spring force and an gap before the hydraulic pressure is admitted to the front disc brakes
- A hydraulic control valve placed in the circuit to the front brakes, designed to restrict pressure to the front brake calipers until the rear brake shoes overcome the tension of the retracting spring
- A hydraulic valve used in some brake systems to slightly delay the application of front-disc brakes to obtain a balanced braking.
- Methane
- (CH4) A colorless, flammable, odorless hydrocarbon gas and the principal constituent of natural gas. Pure methane has a heating value of 1,012 Btu per standard cubic foot. It is colorless and naturally odorless, and burns efficiently without many by products. Local distributors add aromas as a safety measure. It is also an important source of hydrogen in various industrial processes. Methane is a greenhouse gas.
- Methanogens
- Bacteria that synthesize Methane, requiring completely anaerobic conditions for growth.
- Methanol
- (CH3OH)A light, volatile Alcohol that is occasionally blended with Gasoline (typically 3%) to raise octane levels, it is poisonous to humans and causes trouble with rubber and plastic parts of the Fuel system not designed to handle alcohol-blended fuels. It is typically manufactured by steam reforming natural gas. Also formed in the destructive distillation of wood. Also called methyl alcohol or wood alcohol.
- Methanol blend
- Mixtures containing 85 percent or more (or such other percentage, but not less than 70 percent) by volume of Methanol with Gasoline. Pure Methanol is considered an "other alternative fuel".
- Methanotrophs
- Bacteria that use Methane as food and oxidize it into carbon dioxide.
- Methylated spirits
- Almost pure alcohol (which has wood alcohol and coloring added to make it unfit for human consumption); used for cleaning
- Methyl chloroform
- (trichloroethane) An industrial chemical (CH3CCl3) used as a solvent, aerosol propellant, and pesticide and for metal degreasing.
- Methylcyclopentadienyl Manganese Tricarbonyl
- (MMT) An organic manganese compound. It is used as a fuel additive designed to enhance octane levels in gasoline.
- Methylene chloride
- A colorless liquid, nonexplosive and practically nonflammable. Used as a refrigerant in centrifugal compressors, a solvent for organic materials, and a component in nonflammable paint removers.
- Methyl Ester
- A fatty Ester formed when organically derived oils are combined with Methanol in the presence of a Catalyst. Methyl ester has characteristics similar to petroleum-based diesel motor fuels.
- Methyl Tertiary Butyl Ether
- (MTBE) (C5H12O) A high octane, low volatility Ether. It is a petroleum-based product produced from Methanol and Isobutylene. It is not very toxic but is not very biodegradable. The resulting ether has high octane and low volatility. It is a fuel oxygenate and is permitted in unleaded gasoline up to a level of 15% by volume.
- Metric thread
- The threads of metric nuts, bolts, and screws. Two primary styles were common ISO
(International Standardization Organization) and JIS (Japanese Industrial Standard)
which is no longer used. UNC thread and
UNF thread cannot be interchanged with any metric nut
or bolt.
Nominal diameter Width across flat Pitch ISO JIS ISO JIS 3.00 mm 5.50 mm 6.00 mm 0.50 mm 0.60 mm 4.00 mm 7.00 mm 8.00 mm 0.70 mm 0.75 mm 5.00 mm 8.00 mm 9.00 mm 0.80 mm 0.90 mm 6.00 mm 10.00 mm 10.00 mm 1.00 mm 1.00 mm 8.00 mm 12.00 mm 14.00 mm 1.25 mm 1.25 mm 10.00 mm 14.00 mm 17.00 mm 1.25 mm 1.25 mm 12.00 mm 17.00 mm 19.00 mm 1.25 mm 1.50 mm 14.00 mm 19.00 mm 21.00 mm 1.50 mm 1.50 mm 16.00 mm 22.00 mm 23.00 mm 1.50 mm 1.50 mm 18.00 mm 24.00 mm 26.00 mm 1.50 mm 1.50 mm 20.00 mm 27.00 mm 29.00 mm 1.50 mm 1.50 mm Also see
- Metro driving
- An American term for driving exclusively in the city rather than on the highway. The British term is urban driving.