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Mopar Glossary

What is/are?
  Mopar definitions

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AHRA: Acronym for "American Hot Rod Association."

Allen wrench: A rod with six sides and often L-shaped. Used to remove certain screws and fastenings, especially set screws. Sometimes called "hex wrenches" or "Allen key."

Armature: In a relay, regulator, horn, etc., it is the movable part of the unit. In a starter or generator, it is the portion that revolves between the pole shoes, made up of wire windings of copper on an iron core or axle. When it revolves, an electric current is induced.

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Bearing: 1. The area of a unit in which the contacting surface of a revolving part rests in order to minimize wear and friction between two surfaces. 2. An anti friction reducing device that is usually found between two moving parts. The babbitt bearings found between the connecting rod and the crankshaft are lubricated and cushioned with oil, and the front wheel bearings must be repacked with grease at regular intervals. Bearings can be ball or roller type. Also see anti-friction bearing, ball bearing, big end bearing, carrier bearings, clutch pilot bearing, friction bearing, insert bearing, main bearing, needle bearing, precision insert bearing, roller bearing, sealed bearing, tapered roller bearing, throw-out bearing, and thrust bearing.

Bell housing: Sometimes called "clutch housing." The metal covering around the flywheel and clutch (of a manual transmission) or torque converter assembly (of an automatic transmission).

Bladder: A hollow bag which can be inflated. In some instances, fuel tanks will become rusty inside. A possible cure is to install a bladder. This is done by flushing out the rust chips, applying an acid solution to remove any oil/gas residue, and coating the inside with a plastic compound. When done correctly, this plastic coating does not dissolve when it comes in contact with gasoline.

Bleeding the brakes: This refers to the removal of air from the hydraulic system, bleeder screws are loosened at each wheel cylinder, (one at a time) and brake fluid is forced from the master cylinder through the lines until all air is expelled.

Block: That part of the engine containing the cylinders. Also see cylinder block, EN-block, brake pad, block heater, die, mono block, rubbing block, and sanding block.

Blown head gasket: A gasket that has a break between the opening for the cylinder and an opening for the coolant. The coolant will leak into the combustion chamber. This condition can be diagnosed by a loss in coolant and white smoke out the exhaust.

BLOWER - Also called a "supercharger" or "turbocharger." This is a pump which forces air into the cylinders at higher than atmospheric pressure. The increased pressure forces more air into the cylinders than what would be drawn in normally. In this way the engine can burn more fuel and thus produce more power. There are two main types of blowers: The turbocharger, which uses some of the waste heat energy in the exhaust gases to drive a compressor and pump the air; and the belt-driven or shaft-driven supercharger which uses engine power to pump air.

Bored: To increase the diameter of the cylinder.

Burn rubber: ( AKA Burnout) The action of rapid acceleration where the wheels make rapid rotation, but there is only very little momentum. As a result, the driving wheels leave some rubber behind on the pavement.

Bushing: 1. A protective liner or sleeve that cushions noise, friction, or movement. Suspension bushings are often made from two pipes (one inside the other) with a sleeve of rubber in the space between the two pipes. 2. Rubber bushings on the suspension system should be lubricated regularly. 3. A bearing for a shaft, spring shackle, piston pin, etc., of one piece construction which may be removed from the part.

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Caliper : In a disk brake, a housing for cylinder, pistons and brake shoes, connected to the hydraulic system. The caliper holds the brake shoes so they straddle the brake disc.
Coolant : The mixture of water and antifreeze that picks up heat from the engine and transfers it to the air passing through the radiator. This transfer of heat keeps the engine operating within its optimum temperature rant preventing premature engine wear.

Camshaft: A shaft with cam lobes (bumps) which is driven by gears, a belt, or a chain from the crankshaft. The lobes push on the valve lifters to cause the valves to open and close. The camshaft turns at half the speed of the crankshaft. Also see double-overhead cam, overhead cam, race camshaft, and three-quarter race camshaft.

Catalytic converter: A pollution-control device found on the exhaust system of all cars since its introduction in 1974 which acts like an afterburner to reburn unburned gas in the tail pipe. It looks like a small muffler and is usually made of stainless steel. It contains platinum, rhodium, or palladium which is a catalyst for the chemical reaction needed to burn off any unburned hydrocarbons and carbon monoxide by turning them into water vapor, carbon dioxide and other less toxic gases. Also see three-way catalytic converter.

Chassis: Generally, chassis refers to the frame, engine, front and rear axles, springs, steering system, and fuel tank. In short, everything but the body or cab and fenders. Because most modern automobiles (apart from trucks) do not have a separate chassis, the body is sometimes called the chassis. Also see cab chassis and cowl chassis.

Concept car: A vehicle that is not currently in production, but is still in the design stage. Some are merely paper drawings, but others are clay mock-ups. The ideas in the concept cars sometimes appears in production models.

Condenser: 1. A small metal cylinder which is usually located in the distributor. It is installed between the breaker points and coil to prevent arcing at the breaker points by absorbing or storing the excess current. A condenser (also called a "capacitor") has the ability to absorb and retain surges of electricity. It is constructed of two metal plates separated by an insulator. 2. The unit in an air conditioning system that cools the hot compressed refrigerant and turns it from a vapor into a liquid. Also see steam engine.

Crankshaft: A main rotating shaft running the length of the engine. The crankshaft is supported by main bearings. Portions of the shaft are offset to form throws to which the connecting rods are attached. As the pistons move up and down, the connecting rods move the crankshaft around. The turning motion of the crankshaft is transmitted to the transmission and eventually to the driving wheels.

Crankcase : A shaft with one or more cranks, or "throws," that are coupled by connecting rods to the engine's pistons. The combustion process creates reciprocating motion in the rods and pistons which in turn is converted to a rotating motion by the crankshaft.
Cross member : One of several horizontal members in a vehicle frame which join the side members and add to overall strength and stability.

Cu. in.: Abbreviation for "cubic inch"

Cylinder head: The detachable metal (aluminum or iron) section that is bolted to the top of the cylinder block. It is used to cover the tops of the cylinders, in many cases the cylinder head contains the valves, it also forms part of the combustion chamber. It has water and oil passages for cooling and lubrication. It also holds the spark plugs. On most engines a valve cover or rocker arm cover is located on top of the cylinder head. Some engines have just one cylinder head covering several cylinders, while others have separate heads for each cylinder. In some motorcycle engines and small engines, the cylinder head is not detachable -- it is cast with the cylinder which forms a blind hole.

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Differential: A unit that takes the power of the rotating drive shaft at right angles to the rear axle and passes it to the axle. It will not only drive both rear axles at the same time, but will also allow them to turn at different speeds when negotiating turns. In this way the tires do not scuff or skid. Also see limited-slip differential.

Differential gears: The gears that transmit engine power to the driving axles and are arranged so as to permit the rear wheels to turn at different speeds as required when the vehicle is negotiating a turn.

Distributor: 1. A unit in the ignition system designed to make and break the ignition primary circuit and to distribute the resultant high voltage to the proper cylinder at the correct time. The high voltage comes from the coil to the center terminal of the distributor cap and passes down the rotor. As the rotor turns, contact is made with each successive terminal on the circumference of the distributor cap. From there, the voltage goes into the spark plug wires and to the spark plug. Generally when your vehicle has its timing adjusted, it is the distributor that is adjusted. Also called "ignition distributor." 2. A distributor performs many of the same functions as wholesalers, such as selling, physical distribution, credit, etc.; but is between the dealer and the wholesaler. Some industries use the term distributor instead of wholesaler.

Drag race: A competitive match between two vehicles in which they race over a 1/4 mile course.

Dual carbs: Two carburetors on the same engine.

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Flywheel: A relatively large and heavy wheel that is attached to the back of the crankshaft to smooth out the firing impulses. It provides inertia to keep the crankshaft turning smoothly during the periods when no power is being applied. It also forms a base for the starter ring gear and, in manual transmission, for the clutch assembly. Also called "engine flywheel."

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GASKETS - Any of a wide variety of seals or packings used between matched machine parts or around pipe joints to prevent the escape of a gas or fluid.

Gearbox: The device in the drive train consisting of an input shaft, a system of gears, and an output shaft that multiplies engine torque. A manual transmission consists of a clutch assembly plus a gearbox; and automatic transmission generally consists of a torque converter plus gearbox. Also see constant mesh gearbox, planetary gearset, and rack and pinion gearbox.

GEAR RATIOS - The ratio of the speed of rotation of the powered gear of a gear train to that of the final or driven gear

Glass pack muffler: A straight through (no baffles) muffler using fiberglass packing around a perforated pipe to deaden exhaust sound.

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Head: 1. The upper part of something. 2. A part of the engine which covers the piston and creates the combustion chamber. The proper name is cylinder head. See blown head gasket composite headlight, double-overhead cam exhaust header F-head engine, flathead gib-head key head gasket head restraint head tube heads up display headlight headliners headset headers high compression head, I-head engine, Jaguar Drophead L-head engine Lagonda Drophead overhead cam overhead valves Phillips head screw piston head sealed beam headlight T-head valve-in-head engine.

Head gasket: The gasket at the top of the cylinder and sits between the cylinder and the head. It keeps the coolant out of the cylinders and retains compression in the cylinder. Also see blown head gasket.

Hemi: Engine using hemispherical -shaped (half of a globe or sphere) combustion chambers. The valves are cocked at 45 degrees from the piston top. Mopars, despite their fame, are not the only cars with hemi heads.

Horsepower: (HP) A measurement of the engine's ability to perform work. One horsepower is defined as the ability to lift 33,000 pounds one foot in one minute. To find horsepower, the total rate of work in foot pounds accomplished is divided by 33,000. If a machine was lifting 100 pounds 660 feet per minute, its total rate of work would be 66,000 foot pounds per minute. Divide this by 33,000 foot pounds per minute to arrive at 2 horsepower. In metric terms, it is the ability to raise 250 kilograms a distance of 30 centimeters in one second. It is also equal to 746 watts. See brake horsepower, friction horsepower, indicated horsepower, SAE horsepower, SAE gross horsepower, and SAE net horsepower.

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IHRA: Acronym for "International Harmonized Research Activities

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Jake brake: A device which shuts off the exhaust valves manually so that in the exhaust stroke, the burned gasses cannot escape through the exhaust valves. Instead they press against the head of the piston and causes the piston to slow down. When the intake valve opens, some of the exhaust escapes out the intake valve and gives a distinctive loud rapping noise. Jake brakes are used in large truck engines to assist in slowing the vehicle. Many municipal bylaws prohibit the use of jake brakes because of the excessive noise.

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Manifold: A pipe or number of pipes connecting a series of holes or outlets to a common opening.

Methanol: An alcohol that is occasionally blended with gasoline 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. Also called "methyl alcohol" or "wood alcohol."

MOPAR - Trade name of Chrysler Corp for its motor parts (i.e., MOtorPARts). Chrysler also uses the name Autopar to indicate its automobile parts (i.e., AUTOmobilePARts).

MOPARIANS - are persons who favor Mopar based vehicles and usually are known for owning several vehicles of the various Mopar makes. They may or may not be fetishly oriented to the extreme to be called Mophiles.

MOPHILIA - is the medical terminology for a person with Mophile tendencies.

MOPHILE - is vernacular to describe Mopar intrigued or addicted persons.

MUSCLE CARS - correct me if I'm wrong, but the term supercar in the seventies refered to a car that we call a muscle car today. I thought I would let you know to avoid confusion in further communication.

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NOS: Acronym for "new old stock." These are parts that originally were available from the manufacturer of an automobile. They have never been used, thus are "new." But they also may have been on the shelf for decades, thus are "old."

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ORIGINAL RESTORED - is when an automobile with the engine serial number, and the transmission serial number match the VIN, and the automobile has been restored to original factory specifications, although repairs or parts replacements were required to accomplish the restoration.

Overdrive: A unit with a planetary gearset which turns the drive shaft faster than the transmission output shaft. Sometimes the overdrive is an additional gearbox which is mounted in the driveline. Normally the final drive ratio is 1:1; but the overdrive makes it less (e.g., 0.87:1). The overdrive can reduce gas consumption at sustained high-speed driving, engine noise, and engine wear. Also called "overdrive transmission."

Overhead Cam : The type of valve train arrangement in which the engine's camshaft is mounted above the cylinder head(s). When the camshaft is placed close to the valves, the valve train components can be stiffer and lighter, allowing the valves to open and close more rapidly and the engine to run at a higher RPM. In a single overhead cam (SOHC) layout, one camshaft actuates all of the valves in a cylinder head. In a dual overhead camshaft (DOHC) layout, one camshaft actuates the intake valves, and one camshaft operates the exhaust valves.

Oxygen sensor: A pollution control device which measures the amount of oxygen in the exhaust. It controls the fuel-air mixture entering the engine.

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PCV valve: Part of the positive crankcase ventilation system, which reroutes crankcase blowby to the intake manifold and back to the engine, where it is reburned in the cylinders as part of the fuel-air mixture. This cuts emission pollution and improve fuel economy because unburned fuel in the blowby is consumed the second time around. It also keeps the blowby and water vapor from fouling the oil in the crankcase, thus reducing the formation of engine sludge.

Piston : A partly hollow cylindrical part closed at one end, fitted to each of the engine's cylinders and attached to the crankshaft by a connecting rod. Each piston moves up and down in its cylinder, transmitting power created by the exploding fuel to the crankshaft via a connecting rod.

Port: 1. Openings in engine cylinder blocks for exhaust and intake valves and water connections. Also see adjustable variable exhaust port, exhaust port, intake port, transfer port, and valve port. 2. To smooth out, align, and somewhat enlarge the intake passageway to the valves or intake chambers (especially in two-stroke engines). 3. A small hole in the master brake cylinder to permit fluid to return to the reservoir. See compensating port and intake port.

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Rack and Pinion Steering : A steering gear in which a pinion on the end of the steering shaft merges with a rack of gear teeth on the major cross member of the steering linkage. When the steering wheel is turned, the pinion gear turns, moving the rack to the left or right, thus steering the wheels.

Red line: 1. Top recommended engine rpm. If a tachometer is used, it will have a mark (red line) indicating maximum rpm. Some tachometers mark the red line with a colored sector. Others have two lines: The lower one marking the maximum allowable sustained engine rpm, the higher line indicating the absolute maximum rpm. 2. (RL) Tires with a red concentric line which were marketed in the late '60s and early 70s.

Regulator: A device to reduce and control pressure in gas or liquid.

Relay: An electro-magnetically operated switch used to make and break the flow of current in a circuit. As low amperage current is passed through one circuit of the relay, it switches a greater current through another line. For example, when installing auxiliary lights with a heavy draw, the stock light switch may not be able to take the current. Thus a relay is installed so that when the light switch is turned on, low current is sent to the relay. The relay closes the circuit of heavy wiring directly from the battery to the lights.

Resistor: A device placed in a circuit to lower the voltage. It will also decrease the flow of current.

RESTORATION - The act of working on a vehicle with such care as to bring it back to its original condition (including original parts, paint, chroming processes, etc.) rather than merely rebuilding or repairing one.

Rocker arm: A curved lever that pivots in the middle. One end is attached to the top of the valve stem. In overhead-valve engines the other end is attached to the push rod. In some overhead-cam engines the other end is attached directly to the camshaft lobe. As the camshaft rotates, the rocker arms pivot causing the valves to open and close. Also see ball joint rocker arm and high lift rocker arms.

RPM: 1. Acronym for "revolutions per minute." A tachometer measures engine revolutions in terms of rpm. Also see engine speed and red line. 2. Acronym for "revolutions per mile" in measuring the number of times a tire turns in one mile of travel

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SHOTGUN MOTORS - Does anyone remember the 413 shotgun motors? These had the two separate >intake manifolds that were about 2 feet long. I was wondering, since >they are individual manifolds, would it be possible to bolt them onto >a B block? > Yes, I saw a 65 B Body (Satellite I think) at the Houston Mopar Muscle Nationals last year with this set up put in. He had to cut out the inside fender skirts in the engine compartment to fit the cross rams in! I remember he said it was a 383 or 440 engine, not the 413. I think there were a couple of different length cross rams made, he used the real long ones on this car. Looked cool, ran fast!

SPACE SAVER (aka SLANT SIX) - This is an in-line engine in which the cylinder block has been tilted from a vertical plane

SUREGRIP -  rear end performance options 3.91

SWAY BARS -  (a) A bar attached to the hounds, in the rear of the front axle, so as to slide on the reach as the axle is swung in turning the vehicle. (b) Either of the two bars used in coupling the front and rear sleds of a logging sled; also, the bar used to couple two logging cars.

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Tie rod: A rod, or rods, connecting the steering arms together. It links the pitman arm and the idler arm to the steering knuckle arms. When the tie rod is moved, the wheels pivot.

Timing : Timing refers to the crankshaft angles at which the valves open and close and at which time the ignition system fires the spark plugs.

Torque converter: A unit in an automatic transmission, quite similar to the fluid coupling, that transfers engine torque to the transmission input shaft. It also cushions the flow of power. Unlike the fluid coupling, the torque converter can multiply engine torque. This is accomplished by installing one or more stators between the torus members. In the torque converter the driving torus is referred to as the "pump" and the driven torus as the "turbine." The engine drives the impeller which in turn impels fluid against the vanes of a turbine connected through transmission gears to the drive shaft of the automobile. The stator redirects oil flow from the turbine to boost impeller action and multiply engine torque.

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UNDERCOATING - The material sprayed on the underside of the automobile, under the hood, trunk lid, etc. which is designed to deaden sound and prevent the formation of rust.

UNRESTORED- is when a vehicle has not been returned to original factory specifications, and may or may not be either driveable and/or original. >Unrestored means it hasn't been restored - could be a pile of rust, could be an all original 10K mile reference car

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Wedge: 1. Engine using wedge-shaped combustion chamber. The combustion chambers are flatter on one end than the other. 2. A simple machine consisting of a triangular shaped block, that can be forced into a gap, giving a greatly increased force

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