Airbag: A type of adjustable suspension that contains rubber bags that are inflated and deflated, using an on-board compressed air system, to raise or lower the vehicle's ride height. See also hydraulics.
Antique: It all depends on who you ask. Generally it's used to mean a car that's 25 to 30 years old or older, but hobbyists, car clubs, licensing bureaus and insurance companies are all free to set their own meaning of the term. As with the term "classic", there is no single set-in-stone definition.
Bagged: A bagged car has an air-ride suspension. It's also a verb to describe installing the system: "I bagged my car."
Barn-fresh: A vehicle, usually an older antique, that is in unrestored condition, looking as if it had just been pulled out of long storage in a barn. It is becoming increasingly popular to restore the mechanics of such vehicles to safe working condition, but to leave the body and interior in this shape, as it documents the car's original appearance.
Basement: The bottom part of the engine: crankshaft, connecting rods and pistons. Also called the bottom end.
Big Three: General Motors, Ford and Chrysler. The name originated in the days when these three automakers were the largest among a substantial number of now-defunct North American car companies. Given that some import companies are now just as large, these domestic companies are often called the "Detroit Three" now.
Blueprint: An engine that has been rebuilt to its exact design specifications. Most mass-produced engines are built with slightly less than absolute accuracy to their original designs. They work fine for normal driving and are cost-efficient, but these miniscule inaccuracies can reduce performance when the engines are used for racing. A blueprinted engine has had all of its components taken apart and machined to the exact specifications originally indicated by the designer.
Blower: A supercharger, which is a compressor that forces extra air into an engine for extra power.
Bone-stock: An original, unmodified car.
Bore: A cylinder's bore is its diameter. When an engine is bored or overbored, the diameter of the cylinders is increased, which makes the engine's volume larger and increases its power. If an engine is "bored thirty over", it means that the cylinder diameter has been increased by thirty-thousandsth of an inch. If an engine is stroked and bored, the piston stroke has also been lengthened.
Bottom end: The bottom part of the engine: crankshaft, connecting rods and pistons. Also called the basement.
Bottom out: When the car's chassis hits the end of its suspension travel.
Channeled: Most cars prior to the 1940s had their bodies placed on top of their frames. A channeled car has its body lowered over the frame, hiding the frame rails.
Chopped: A roof that's had sections removed from the pillars and welded back on in a lower position. A "two-inch chop" has had two vertical inches of metal removed.
Christmas tree: A series of lights used at the start of a drag race.
Classic: As with the term "antique", there is no single definition accepted by all hobbyists, car clubs, licensing bureaus or insurance companies. Some people use the term to describe a car that falls somewhere between their definition of "antique" and a brand-new car. Others use it to describe specific models -- for example, the 1955-1956-1957 Chevrolets are often called the "Classic Chevys". The Classic Car Club of America has trademarked the term "Full Classic" to describe a car that's on its list of acceptable classics.
Concours d'elegance: A car show, usually open only to higher-end or luxury antique automobiles, held in a lush setting such as a country club. The literal translation is "contest of elegance".
Crash box: A transmission that has no synchromesh. This type of transmission must be double-clutched to reduce wear.
Cutting coils: A method of lowering a car's ride height by cutting out sections of the coil springs.
Decked: To remove chrome trim from a custom car's trunk lid. When the chrome is also removed from the hood, the car is said to be "nosed and decked".
Deuce: A 1932 Ford.
Dog leg: The corner of a wraparound windshield on a 1950s car. It's a multi-purpose term, and is also used to describe, among other things, the rear door jamb on the back door of a sedan, a sharp turn on a race course, or a manual transmission where first to second gear is an up-and-over movement of the shifter.
Double clutching: A technique used with older manual transmissions that do not have synchronizers (a "crash box" transmission). The driver puts in the clutch, moves the shifter into neutral, releases the clutch, and then puts the clutch back in and shifts to the next gear. This extra step allows the engine speed to match the speed of the gears, so the shift is smoother and prevents excess wear on the transmission.
Dropped axle: A special front axle with its wheel spindles higher in relation to the height of the axle than in a stock unit. The result is a lower ride height.
Dual quads: An engine with two four-barrel carburetors.
Fastback: A car design where the roofline continues in a single curve from the windshield to the rear bumper.
Five-window: A 1920s or 1930s two-door coupe with side windows behind the doors. The five windows are the door windows, these quarter windows, and the rear window (the windshield isn't counted). See also three-window.
Flamethrowers: A system that includes spark plugs mounted in the tailpipes, with a switch that the driver hits to make them fire. The plugs ignite raw fuel coming out of the exhaust, resulting in trails of flames out the tailpipes.
Flathead: An engine with its valves in the block alongside the piston, instead of in the cylinder head. The name comes from the shape of the heads.
French: Bodywork that "sinks" items below the surface, such as headlights or antennae. Such sunken headlights are called "Frenched headlights", or are said to be "Frenched in".
Full Classic: A trademarked term used by the Classic Car Club of America to describe vehicles which it considers "classic cars". With some exceptions, the only Full Classics on the list are between model years 1925 and 1948, and in some instances may only be specific models rather than all cars made by an automaker that year.
Goat: A Pontiac GTO.
Hardtop: A coupe or sedan that has no centre or "B" pillar. When all the windows are open, there is no obstruction from the front door to the rear one.
Hemi: An engine with hemispherically-shaped combustion chambers (the area of the engine where a mixture of fuel and air is burned to start the process of producing power). The shape allows for unobstructed movement of the air. The term is now a Chrysler trademark, although other companies have used similar designs.
Hot Rod: An old car customized with a newer drivetrain and any manner of body or interior changes. Also called a "street rod".
Huffer: A supercharger.
Hydraulics: A suspension system that uses oil-filled cylinders to raise or lower the vehicle's ride height. Its popularity with many custom car fans has been usurped by newer airbag suspensions. See also airbags.
Juice brakes: Hydraulic brakes, as opposed to mechanical ones.
Lake pipes: Straight exhaust pipes that run along the lower edge of a hot rod, without mufflers. The name comes from their original use on cars that raced on dry lakes.
Lead sled: A custom car, usually a late 1940s or 1950s car. Although most are customized today with plastic bodyfill, their body modifications were originally done with melted lead.
Long block: A replacement engine including the crankshaft, connecting rods, pistons, heads and head gaskets. See short block.
Matching numbers: A description of a car with the manufacturer's body and engine numbers matching, indicating that it's the engine originally installed in the vehicle at the factory. It's of varying importance to collectors and to a vehicle's value, but it can be useful to prove that a high-performance model is as it's presented, rather than a more ordinary trim line later modified to resemble an original muscle car.
Mill: An engine.
Mopar: A Chrysler product.
Nailhead: Buick V8 engines produced between 1953 and 1966, so named because the narrow valves resembled nails.
NOS: There are two definitions for this. One is New Old Stock, which refers to an old, original replacement auto part that has never been on a vehicle. The other is Nitrous Oxide System, which injects nitrous (also known as "laughing gas") to temporarily boost the power of an internal combustion engine, primarily in racing.
Nose: To remove chrome trim from a custom car's hood, such as the hood ornament. If the trim is also removed from the trunk lid, the car is said to be "nosed and decked".
Post-War: Refers to a North American consumer vehicle of model year 1946 or newer. Civilian car manufacturing was suspended during model years 1943, 1944 and 1945 as the automakers produced war supplies.
Pre-War: Refers to a North American consumer vehicle of model year 1942 or older. Civilian car manufacturing was suspended during model years 1943, 1944 and 1945 as the automakers produced war supplies.
Project car: A Latin term that means "lots of work and money." It's an unfinished car that you buy with the intention of putting it together yourself. It could be just a body shell, or one on a rolling chassis, or one that someone else started but never finished.
Quick-change: A rear differential assembly that can be changed in a few minutes, when a different gear ratio is required for racing.
Rat rod: A hot rod with its body left rusty, and sometimes built with a very rough chassis or mismatched parts. Be careful: some owners like the term, while others think it's derogatory.
Roadster: An open two-seater car without roll-up windows.
Scrub line: The lower edge of the car's wheels. Frame and suspension components should not be below this line, as they can come in contact with the pavement in the event of a flat tire.
Shaved: A car with the door handles and side trim removed, as in "shaved handles".
Short block: An replacement engine block containing the crank, connecting rods and pistons, but without heads, manifolds or external components. See long block.
Six-pack: An engine intake with three two-barrel carburetors.
Sleeper: A high-performance car that doesn't look capable of what it can do. The British use the term "Q-ships", in reference to a naval war practice of outfitting merchant ships with war guns.
Slicks: Wide tires made of very soft rubber with no tread, used in drag racing because they provide maximum traction during hard acceleration. They're not legal for street use.
Sliding scale: A means by which car clubs, shows, insurance companies or licensing bureaus decide vehicle acceptability by model year. While a "cut-off year" stops at a specific year (ie, nothing newer than 1948), a sliding scale uses a pre-set limit, such as 25 years, which allows in a year's worth of newer vehicles each year. For example, a 25-year sliding scale would allow model-year 1982 vehicles in 2007, and model-year 1983 vehicles in 2008.
Street machine: A high-performance car that's legal to drive on the street.
Stock: An original, unmodified car.
Stovebolt: A six-cylinder Chevrolet engine, introduced for 1929; the basic design was used in cars until the 1960s, and as long as the 1980s in some trucks. Also called the "Cast Iron Wonder", it got the name from its bolts, which resembled those used on stoves.
Stroked: An engine modified with a longer piston stroke (the distance the piston can travel up and down in its cylinder) to produce more power. Often combined with boring (increasing the diameter of the cylinder); the resulting engine is described as stroked and bored.
Suicide doors: Doors that are hinged at the rear, rather than the front. Supposedly the name comes from the difficulty in closing them if they come open at highway speeds.
Suspended pedals: Older cars had pedals that came up through holes in the floorboards. Suspended or "swing" pedals, now used on all cars, hang down from the cowl.
Three on the tree: A three-speed manual transmission with its gearshift lever mounted on the steering column.
Three-window: A 1920s or 1930s two-door coupe that has no side windows behind the doors. The three windows are the two doors and the rear window (the windshield isn't counted). See also five-window.
Tupperware car: Derogatory term for a Fiberglas-bodied hot rod.
Wraparound windshield: A 1950s styling cue where the windshield glass was curved into a relatively sharp angle, with the edges protruding past the hinges on the front door. The point is commonly known as the dogleg. Most owners of these cars go through a learning curve when it comes to getting into the car, since it's very easy to bang your knee against the dogleg.