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Terms and Phrases

A through Z

Monitored by Wes Vann, edited on July 17, 1999

This section will always be under construction and your input can't hurt! It's intended to be be both fun and informative.

Know any good ones? Got any that have always bugged you and you just can't figure it out?.

Thanks go to Gene McGill, Steve Strasemeirer, Tim Mattson, Skip Cain, Jesse Contreras, Terry Reid, Jim Foreman, Don Seributra (AKA H50), Wes Wright, Dave Bradley, Zonked23, Leo Paugh, Carl Brume, Mike Reeh, Paul Nazares, and others I may have forgotten (sorry).

I'm going to try highlighting new additions in red. Of course that means that if you don't check here often, you could miss some of the highlighting due to it being changed back to black.

I've added a directory that enables you to jump to the different areas of the page. It's a rather long text file but doesn't take that long to load (only one photo). There will also be several "return to the directory" jumps.


  • "By the Number"
  • A through C
  • D through H
  • I through L
  • M through O
  • P through S
  • T and U
  • V through Z

  • By the Number:

    "2/55 Air Conditioning"; 2 windows down at 55 mph

    "3 on the tree"; three speed transmission with the shifter on the steering column.

    "3/4 cam"; (pronounced "three quarter", not "three fourths". A "three fourths" cam would only work 12 of the 16 valves. Heck, maybe this is what Cadillac was using in their 4,6,8 engines) This is one of those (bogus and vague) terms used in the old days for a high lift, long duration racing cam.

    "383"; a 350 block with a 400 crank (see "stroked").

    "409"; The engine that came before the big blocks. From 1961 to early 1965. You can tell a 409 by the shape of the valve covers. There are two large notches on the lower edge.

    "442"; 4-barrel, 4-speed, dual exhaust. As on those Oldsmobile's

    "4 on the floor"; four speed transmission with a floor shifter

    "4L60"; As far as I know, it's just a new name for the 700R4.

    "4L80"; A stout four speed automatic transmission. Stronger than the 700R4. I believe that it's mostly used in trucks. It's REAL large and you may have problems fitting it under an early Chevelle without reworking the tunnel. There is also a 4L80E that is electronically controlled (dang computers!)

    "4 slammer"; a four door car.

    "6 banger"; a six cylinder car.

    "6 pack"; three two barrel carbs, also see "tri power" (also a common form of packaging beer)

    "700R4"; A good four speed automatic transmission for small blocks. See 4L80 also.

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    "balanced"; One of those over used and under defined terms. It could include items like matching the weights of the rods and also the pistons. Normally, it's used when talking about balancing the rotating mass, it other words, the crankshaft. What you will never hear is the accuracy of the balancing.

    "BBC"; big block Chevy

    "bbl"; barrel or throat on a carburetor, a 4bbl is a four barrel carb.

    "BCCC"; base coat, clear coat. Also know as two stage paint. (Duh, the base coat is the color)

    "BDC"; bottom dead center

    "Big & Littles"; Really big tires on the rear and little tires on the front. We are talking street rod stuff here.

    "Big Block"; Those big chevy engines. The factory engines range in displacement from 396 to 502. They are all (for the most part) the same size outside. Yes, you could make a 502 look like a 396. Also see "small block".

    "Blueprinted"; I really hate this term! It has to do with making the dimensions of the parts in the engine more accurate (and closer to the blueprint values). What you will almost never hear from the average joe is what values were used!

    "BOP"; Buick, Olds, Pontiac --- In other words, not Chevy.

    "Bored"; When the cylinder diameter is enlarged over stock. This could be a simple 30 thousands "over-bore" to rebuild an engine or on up to the limits of the block casting. You need new pistons any time you bore out an engine.

    "BTDC"; before top dead center

    "btw"; by the way

    "btdt"; it's short for "been there, done that"

    "Bump Stick"; A camshaft.

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    "cabriolet"; it's another word for convertible

    "cc'd"; cc stands for cubic centimeter and it's a measurement of volume. Kind of like quarts. When a head is "cc'd", you are checking the volume of the combustion chamber. All of the chambers should be the same volume. You need to know the volume in order to figure out the compression ratio.

    "CFM"; This is a carburetor term and stands for "cubic feet per minute". It's the volume of air (over time) that the carburetor can pass. Bigger isn't always better! (thanks to Dustin, aka BlazinZ28, for this one)

    "channeled"; A custom car term used when the car body is mounted lower on the frame. This requires that the floor be cut out and "channeled" over the frame. The car body is lowered, but the frame is not!

    "chopped"; A custom car term where the roof is lowered.

    "COE"; This shouldn't be confused with CEO. If you meet a lady and she says that she loves the CEO she has a home, walk away! If she says she loves the COE, buy her a drink! COE stands for "cab-over-engine" and it's normally used when talking about those old pug nosed trucks.

    "convertible"; The only reason I'm including this is to explain the difference between a convertible and a roadster. A roadster has bolt on side windows (or no side windows at all). A roadster is a convertible, but a convertible may not be a roadster.

    "COPO"; Central Office Production Order. I wish that I could make up one!! It's an order to construct a non-standard car configuration. How about a COPO to put a L88 in a new Camaro??

    "coupe"; A hard topped car without frames around the door windows. A sedan has a frame that's mounted to the door. As an example, a 70 Chevelle is a "coupe", a 64 Chevelle is a sedan.

    "cowl"; I could be wrong here, however I believe it's the body area just in front of the windshield.

    "crate motor"; An assembled and ready to run engine. Of course, this is after you add things like the intake manifold and such.

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    "decked"; This is a machine shop term used on both blocks and heads. It is machining the surface that is in contact with the head gasket. You do decking for two reasons. The first one is to make sure the surface is flat. The other reason is to make sure that the surface is parallel to the crankshaft. A head may be blocked in order to equalize the chamber volumes. Due to removing material, the compressed volume gets smaller and the compression ratio is increased. Deck it too much, and you have to start worrying about the piston hitting the head!

    "deformed thread" nuts; This is a nut where the threads are deformed such that the nut will not work loose. PLEASE don't use metric nuts thinking that they are just "deformed thread" nuts! Unlike Nylok nuts, they can be reused (within reason). Also see Nylok nuts.

    "Double Pumpers"; Heck, even Jill on Home Improvement has used this term. It's referring to a Holley mechanical secondary carburetor. There is a second accelerator fuel pump on the secondary side of the carb.

    "differential"; It's the mechanism in the rear end. Note that I didn't just say "the gears"! The "differential" function is done by the spider gears deep inside and not the ring and pinion gears. It allows one wheel to rotate faster than the other. The reason a street car needs this is that when you go around a corner, the wheel on the outside has to turn faster than the inside wheel (it has to go farther). Also see "posi" and "spool".

    "dry manifold"; When a system is a "tpi" style, the fuel (the wet part) isn't injected until just before the valves. Thus, the manifold remains "dry". Also see "wet manifold".

    "Dual Quad"; Two four barrel carbs.

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    "EFI"; electronic fuel injection. The old fuel injections used in the 65 Corvettes was a mechanical fuel injection, as was the Hilborn fuel injections.

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    "flight line": This is from my dad. When he worked on airplanes, it was always fun to send somebody out for a yard of flight line. In reality, it's where they park the planes prior to flight checking.

    "Float the Valves"; rev the engine so high that the valves don't return to a closed position.

    "Ford"; Some people would have you think that it stands for "First on Race Day". Well, here are the more truthful acronyms. Fix Or Repair Daily, Found On Road Dead, Forged Out of Recycled Dumpsters. Then there is the fact that Ford backwards is; Driver Returns On Foot

    "front clip"; the front end sheet metal forward of the firewall. On a Chevelle, this should include the fenders, hood, radiator core support, bumpers, etc.

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    "Glide"; slang for Powerglide

    "Grade 8" bolts; Bolts are graded for strength and grade 8 is the best that I know of. (I can feel the e-mail coming in now) An interesting fact is that there isn't a grade 8 stainless steel bolt due to the fact that in order to make something "stainless", it has to have a lower iron content. As a result, they are not as strong.

    "Grocery Getter"; Something to get you from point A to point B with no flash involved. (This term was given to me by Steve Strasemeir and he defined it as an "old days" term for a station wagon. My 64 2 door wagon wants to have words with him about it!)

    "GTO"; "Get the Tools Out", or "Gas, Tires, and Oil". No, really it stands for "limited production" grand touring. (some "limited production") I've finally gotten what I think is the correct wording for GTO (thanks to Don Seributra). It's Gran Tourismo Omologato and was originally coined by Enzo Ferrari.

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    "honed"; This is the grinding process on a cylinder. It applies to both the piston cylinders and also for lifter bores. Honing removes only a small amount of material. When honing the cylinders, the pattern is also important due to it helping the piston rings setting in. (most of the time you will see a cross-hatch pattern after honing)

    "HVLP"; high volume, low pressure. It's the new EPA approved type of paint spray gun.

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    "Indexing" spark plugs; This is where you concern your self with the position of the terminals of the spark plug inside the combustion chamber. You would want the gap "pointing" in a certain direction( I don't know what direction, so, please don't ask). It's done by marking a line on the outside of the plug indicating the position of the terminals and then playing with shim gaskets to get that position when the plug is tightened down.

    "IMHO"; in my humble opinion

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    "Johnson Rods"; Hopefully your car doesn't have bad johnson rods. There really is such a thing on a car. However, they are on steam train locomotives. They're the rod that connects to the wheel that drives it.

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    "L34"; 360/350 hp 396

    "L35"; 325 hp 396

    "L36"; 385/390 hp 427

    "L48"; 300HP/ 350cid

    "L66"; 265 hp 396 with 2 bbl (1969 only)

    "L68"; 400 hp 427 with 3 2 bbls (tri-power)

    "L71"; 435 hp 427 with tri-power

    "L72"; 425 hp 427

    "L78"; 375 hp 396 (425 hp in 65 Corvette)

    "L88"; 430 hp 427 (my trusted expert states that the 430 hp quoted is way under-rated) Also see ZL1.

    "L89"; An L78 with aluminum. heads

    "LS1"; 335 hp 427 (1969 only)

    "LS3"; 330 hp 402

    "LS4"; 345 hp 454

    "LS5"; 390 hp 454

    "LS6"; 450 hp 454

    "LS7"; 465 hp 454. It's a 454 version of the L88 that was designed for the 1970 Corvette, but was never released for production (in the car). It was (is?) available over the counter only.

    "Ladder Frame"; This is the type of frame that exists on Chevelles. It could also be referred to as a "perimeter" frame. There are two main frame rails that run parallel to one another that are close to the edge of the car. Most cars that have a separate frame are of this design. Also see "X frame".

    "line-bored"; When you have several bearing that have to be in line (as in for the camshaft or crankshaft), you line bore. The machine is a long bar that supports it's self off two of the bearings while cutting the third. When line boring the bearing surfaces for the crankshaft, the caps have to be torqued down and marked for position. After line boring, you can't swap around the caps!!!

    "Long Block"; It's an assembled engine that has the heads already attached. It doesn't necessarily include the intake manifold or things like the water pump. (Some "crate" motors do include this stuff and you have to check so that you can figure out the value for your dollar. The ZZ4 engine even comes with the distributor!)

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    "MAP sensor"; manifold absolute pressure. It a sensor used in fuel injection systems.

    "Mechanical secondarys"; When the secondary barrels on a four barrel carb are opened up by the linkage on the side of the carb. Also see "vacuum secondarys".

    "Mini-tubs"; So you want to run big tires on the rear, but they just will not fit. If you want to be sneaky, that rules out "tubs". The answer is mini-tubs. This is when the inner fender is cut and sectioned inward (toward the center of the car). The opening is filled with sheet steel and is welded back together. If done correctly, it's not that notable if somebody looks in your trunk. Also see "tubs".

    "Mopar"; Mostly Old Parts And Rust, My Old Pig Ain't Running, Motor Often Pulled And Repaired.

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    "NOMB"; None of my business

    "NOS"; New Old Stock. It's old items that the manufacturer (GM) has discontinued, but may still be sitting on some shelf somewhere. Some of this stuff is priceless to those "numbers matching" restoration guys (you know who you are!) ("NOS" is also a company name for a supplier of nitrous oxide systems)

    "NOYB"; None of your business

    "Nylok" nuts; These nuts have a nylon section within them that provides friction on the bolt threads. You can NOT just keep reusing nyloks due to the nylon taking the shape of the threads and loosing their grip. You should also NOT use them on things like headers where the heat could melt the nylon. Also see "deformed thread" nuts.

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    "O2 sensor"; oxygen sensor. Normally used by fuel injection systems to vary the amount of fuel required.

    "One Legger"; A car without a posi unit. Only one wheel is driven if the other hits an oil spot.

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    "Panard Rod"; A rod that limits the side to side movement of the car. It's normally at the rear of the car, however on some street rods (real old stuff) it could be used also on the front. There is a long rod that runs from one side of the car and the other end is attached to the differential.

    "Perimeter Frame"; see ladder frame

    "phasing" a driveshaft; This may at first sound hard to believe, but when the drive shaft isn't perfectly in line with the transmission, due to the universal joints, it doesn't rotate at a constant speed, even if the transmissions rotation is constant! It speeds up and slows down as it goes through a complete rotation. For this reason, the rear-end has to be set up with it's centerline parallel to the transmissions centerline. This counteracts (or takes out) the speeding up and slowing down of the driveshaft.

    "pinion gear"; It's the small "drive" gear in the rear-end. See "ring gear". The end of the pinion gear shaft is where the driveshaft universal is attached.

    "Pink Slip"; No jokes about women's apparel. You may remember the reference in an old Beach Boy about having "the pink slip daddy". Well, here in California, the "pink slip" is what the department of motor vehicles gives you once you own the car (the bank is paid off).

    "Piston return springs"; Used in high RPM engines to make sure that the piston goes back up to TDC in time. Just kidding!!

    "Polished"; I got asked about this one while the subject of engine terms were being talked about. In regards to engines, the most common usage would be in polishing the intake ports for better flow.

    "Protecto-plate"; Back in the 70's, they were a stamped ID card that was attached to the warranty booklet that came with a new car. They had both the car information and also original owner's ID. If the card still exists, it's good for documenting the cars "numbers".

    "Ported"; For the most part, this is talking about work that is done on the heads. It involves using a grinder to change the shape of the intake and exhaust ports for better flow.

    "port matching"; This is matching the intake manifold ports to the heads ports so that there is a smooth transition.

    "Posi"; A "positraction" differential unit. There are various types and configurations. The basic intent on all of them is to prevent one wheel from getting all the driving force if the other wheel looses traction.

    "powerglide"; The older two speed automatic transmissions. Pretty weak, but can be built up for drag racing if you have enough money.

    "punched"; As in, "the block has been punched". It means that the block has been bored out.

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    "ring gear"; It's the large gear in the rear-end. It mates with the pinion gear and the ratio of the two (number of ring gear teeth divided by the number of pinion gear teeth) gives the rear end ratio. You could also see pinion gear if you wanted to. Well, I got called out on this one and should add a few notes. The gear that is on the flywheel is also called a "ring gear". The gear in the differential would more correctly be called a "crown" gear, however, I think that the usage of the term "ring" gear is commonly excepted.

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    "SBC"; small block Chevy

    "Secondarys"; On a four barrel carb, there are a pair of "primary" barrels and a pair of "secondary" barrels. The secondarys open up when the car is floored.

    "Sectioned"; A custom car term defining when the car body is cut, a section removed, and then reattached. Normally the cut is a horizontal cut at the belt-line. Please don't try this at home!

    "Slammed"; What your girl friend does to your car door when she finds out how much you spend on your car in relationship to her. (some things should be kept secret!) In car-nut terms, it means a severely lowered car.

    "Short Block"; When you buy a short block, it doesn't come with the heads. Normally it would include the block, crank, rods, pistons, and cam. All of this is assembled and ready for your heads. You should also see "long block".

    "Sleeper"; A car that intentionally doesn't look as fast as it is. Think about a bored and stroked big block (that looks like a stock 396) in a beat up station wagon.

    "Small block"; The factory engines that range in size from 283 to 400. They are all the same size outside. Yes, it's possible to have a small block with more displacement than a big block.

    "Speed Nuts"; Hey, we like Chevelles, we must all be speed nuts. No, really, they are the nuts that hold on things like emblems. They are made from sheet steel and screw on a non-threaded stud shaft.

    "Spool"; It's a "ring gear" carrier that takes the place of the differential. This is a drag racing (I never have to turn) item. If running a spool on a street car, it forces both tires to turn at the same speed while rounding a corner. This means that one tire has to loose traction. Not a good thing while driving through a canyon or in the rain!

    "Stroked"; This is when the piston stroke is increased over stock. It requires a modified (or different) crankshaft. The most common "stroked" engine is the 383. It's a combination of a 350 block with 400 crank. (the 400 crank requires minor modifications to the bearing surfaces)

    "stoichiometric ratio"; (try spelling that without looking it up!) It's the ratio of fuel (gasoline) to oxygen. Normally a car runs best with a ratio of 14.7 (I think). It's the job of the carb or EFI to maintain that ratio. The ratio would be different for different fuels.

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    "Tall block"; Normally a truck block (when talking production stuff) that has a taller deck height than a standard block. This allows a longer stroke.

    "TBI"; Throttle body injection. On this type of injection, the injector (or injectors) are mounted in the throttle body. The throttle body looks (and is mounted) like a carburetor. Also see "wet manifold".

    "TCS"; Transmission Controlled Spark. Installed on all engines starting in 1970, It switched in or out the vacuum to the distributor depending on temperature and transmission gear.

    "TDC"; top dead center

    "TH350"; TurboHydromatic transmission. Three speed automatic. Good for most small blocks.

    "TH375"; (or is it TH425?) TurboHydromatic transmission. Three speed automatic. From what I under stand, it's a TH400 with cheap gears.

    "TH400"; TurboHydromatic transmission. Three speed automatic and strong as all get out. If you have tons of torque, this is the trans to use.

    "Throttle Stop"; A device mounted on the carb that limits how far the throttle can be opened. Plan on there being one on a rental truck. (I wonder if there were ones on the Shelby GT350 mustangs that you used to be able to rent (yes, I'm that old! Heck, I remember seeing new Cobras at the local Ford dealer.))

    "TPI"; Tuned port injection. On a TPI injection (on a V8), there is a injector at each port of the intake manifold right near to where it mounts to the heads. Also see "dry manifold".

    "tri power"; three carbs, normally 3 two barrel carbs

    "Tubs"; When you want to run those monster big slicks, you have to make room for them! This means that you have to cut out the inner fenders. The opening is filled with "tubs". Here is a scan that I got from an ad in one of the car magazines. Also see "mini-tubs".

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    "vacuum secondarys"; This is when the secondarys are controlled (opened) by the manifold vacuum. The other way is with mechanical linkage (as in the Holley double pumpers).

    "VIN"; Vehicle Identification Number. It's the number that Chevy puts on your car and can be broken down to tell you what options were added. (PLEASE don't e-mail me asking for a break-down of your VIN!)

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    "Watts linkage"; This is the linkage that is used on race cars that prevents side to side movement of the car.

    "WOT"; Wide Open Throttle

    "wet manifold"; When you have a carb or "tbi" setup, the manifold runners are called wet due to the fact that fuel is present. See "dry manifold".

    "W-series engine"; 348 and 409 engines used from 1958 through 1964

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    "X frame"; This type frame was used on the older Impala's. The frame rails pinch in towards the driveshaft in the middle of the car. At both the front and the rear, the frame rails go wider for the attachment of the front and rear suspension. One of the problems with this type frame set-up has to deal with side impact protection. Also see "ladder frame".

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    "Z-bar"; This is the clutch bell crank when running a manual transmission.

    "Z16"; 375 hp 396 (1965 Chevelle only)

    "ZL1"; same as L88 except for all alum. 427 block

    "ZZ4"; 355 hp 350 Chevy crate motor

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