This page is a work in progress. It is here to help establish a
dictionary of NCRS Lingo. New members and old members alike sometimes question what
some of the terms used to describe our Corvettes and the restoration process that we go
through to make them ready for NCRS Flight Awards®.Terms
with an * are taken from an official GM Abbreviations/Acronyms Manual.
Big Block Chevrolet engine. Engines that started in 1965 with 396 cubic inches and progressed to 427 cubic inches
for 1966 and then to 454 cubic inches from 1970 - 1974.
BC/CC
Base coat/clear coat paint *
BHP
Brake horsepower *
Big Block
Engines that started in 1965 with 396 cubic inches and progressed to 427 cubic inches
for 1966 and then to 454 cubic inches from 1970 - 1974.
Big Brake
Big Brake option available on 1957 through 1962.
Big Tank / Tanker / No Carpet Club
Optional larger gas tank, available 1959 through 1967.
Bolt on Wheels
Aluminum wheels on 1967 Corvette that appeared very much like the 1963-66 Knock-off
wheels, except that they bolted on just like standard wheels.
BOM
Bill of materials, used at prototype build sites as part number list for each vehicle *
Broach Marks
The marks on the deck of the block including the stamp pad, created by the factory
machining operation. Broach tool; leaves lines as the cutter moves across the deck in
a straight line from front to back. The ridges or grain of the marks will vary quite a bit
from engine to engine as the tooling wears or other factors enter into the process.
Re-stamped blocks are first decked to erase the original numbers and; most automotive
machine shops cut and leave broach marks across; the block side to side, which are
readily detected when inspecting a stamp pad. However, some very cleaver and
expensive shops cut the blocks like the factory so they can re-stamp and be nearly
undetected.
BPEGR
Back pressure exhaust gas recirculation *
BSW
Black sidewall tire *
BTC
Body Technology Center *
BTDC
Before top dead center *
Build sheet, Tank Sticker
It lists all the options the car had originally. Starting in with '67s, it is glued to
the top of the gas tank. Later years also may find them stashed various places inside the
car. A great piece of authentication, since Chevy has no records of how each car was
equipped. The National Corvette Museum has recently been given access to copies of all of
the build sheets from the Bowling Green Plant. This applies to 1981 and later cars
that were manufactured at Bowling Green. The Museum is now offering a service of
reproducing a copy of the build sheet and the Window Sticker. See the NCM web
site for further information. Like everything else, can be faked.
1953 -1962 Corvettes. The solid axle or straight axle cars.
C2
1963 - 1967 Corvettes. Mid-years and Sting Ray years.
C3
1968 - 1982 Corvettes. Includes 1968 Shark, and 1969 - 1976 Stingray years.
C4
1983 - 1996 *note: There were no 1983 production cars due to plant
change over from St. Louis to Bowling Green.
C5
1997 - 2004 Corvettes.
C6
2005 - and later Corvettes.
CAFE
Corporate average fuel economy *
CAMSHF or CAM
Camshaft *
Casting Number
Part number cast into a part as it is produced. Many castings also
have a date code cast into the part as well. Parts such as blocks, manifolds,
heads, transmission cases, differential cases and many more have casting numbers
that identify them as particular to certain applications. On most Chevrolet
blocks the casting number is located on the bellhousing flange behind the
driver's side head. This can usually be seen even with ignition shielding
in place.
CB
Citizens band (radio) *
CDI
Capacitor-discharge ignition system *
CEL
Check engine light (display) *
CFI
Cross fire injection *
CID
Cubic inch displacement (of engine) *
COM
Chassis Overhaul Manual
Convertible
Cars with a fold down canvas like top, and roll up windows.
COPO
(Chevrolet) Central Office Production Options (formerly), now SEO * Combinations
of options that were generally not available to the public. The order was
generated through the Chevrolet Central Office.
Coupe CPE *
A closed car with two doors.
CPO
Chevrolet part number only *
Crossfire Injection
Standard on 1982 model only. First fuel injection since 1965 two injectors
in a throttle body setup.
Almost every mechanical part made for a Corvette has a date code either cast or stamped
into it. These are used by the manufacturer to track quality control. They are now
used to determine if the part is probably correct for the Corvette it is installed on.
An engine with a date code of C 10 4 (March 10, 1964) could not be correct for a
'63 Corvette as the engine was made after the car was made. Parts too early are usually
not correct either, as they would have been installed on an earlier vehicle, such as a D
19 5 (April. 19, 1965) in a '67 Corvette. The date code on an engine block is typically on
the bellhousing flange behind the distributor. On early big blocks, it was on the passenger
side near the pan rail, but later (1970) moved up to the same location as the Small
Blocks.
DIST
Distributor (an engine part) * Distributes spark from coil to spark plugs.
Controls spark timing.
DLI
Distributorless ignition system *
Documentation, History
Depends on who is listening to the pitch. Many cars have no documentation or history. It
is a good thing to have. You can check up on when modifications were done, where stuff
like missing ignition shielding went, etc. If there is something atypical about the car,
like a hand-stamped block, you can sometimes get affidavits from former owners that this
is the original block and was never removed from the car.
DWO
Design work order
DYNO
Dynamometer * Device for measuring mechanical force, or power.
Fuel Injection. Early cars 1957 - 1965 used Fuel Injection that was unlike our
modern electronic Fuel Injection cars of today. They often were very difficult for
mechanics to adjust or maintain. They were often taken off of cars and replaced with
carburetors. That history leads to today's restored Fuel Injection cars being a
little rare.
Replacement engine assembly includes block, crank, cam, pistons, rods, heads and valve
train components all assembled and ready to install. Timing gears and chain are also
included. The oil pump is commonly installed. This is the basic engine
including all of the parts for that base engine. Things like covers, waterpumps,
flywheels, and other parts that may vary depending on the application are not included.
This engine may be serviceable in a Corvette or a 9 passenger van. Either
with an automatic transmission or four speed. Fuel delivery may be carburetor, or
fuel injection. This is why certain parts may be included on one version and deleted
on another. GM refers to this as a "Targetmaster" engine.
National Corvette Museum. Bowling Green, KY. Just across the
road from the Bowling Green Corvette Plant. NCM
web site
NM
*NM*NCRS Technical Discussion Board and NCRS Discussion
Board. Identifies a message with no content, or no message.
NOM
Not Original Motor. This may or may not matter to you, but it probably will
to someone else if you have to sell the car later. Pay less for NOM.
NORS
NOS refers to New Old Replacement Stock. These are parts that have
been laying around in their original boxes since who knows when. They
are usually preferred over reproduction parts, but they are not always correct
for your car. There were many parts for our Corvettes that were used
on the assembly line that were never sold as replacement parts. For
any number of reasons the replacement parts could be configured differently
than the parts that the car was delivered with. That is one of the reasons
that NCRS is so serious about Bowtie cars. These are examples of cars
that remain unrestored, unmolested original cars. They may not look
like much to the casual observer, but to many NCRS members they are a living
laboratory where we can see how the factory assembled these cars and what
parts were used on the days that our example car was assembled.
NOS
NOS refers to New Old Stock. These are parts that have been laying
around in their original boxes since who knows when. They differ from
NORS in that the part is identical to the part used during assembly. The problem
here is knowing NOS from NORS. Experience and consulting with Team Leaders,
Master Judges, and other trusted sources is the only way to know.
MPL
Master parts list (computer code) *
MVMA
Motor Vehicle Manufacturers' Association (successor to AMA)
Original Equipment Manufacture. Many times these are not manufactured by GM but
subcontracted to one or more vendors. The parts from different vendors may vary
slightly. These parts often were and are mixed during the production runs.
A high performance SERVICE engine assembly usually configured differently than any
available PRODUCTION engines. It is composed of PRODUCTION and GMPP components
PG
Powerglide Transmission
PID
Part identification (in MPL) *
P/N PTN
Part number
Positrac / Positraction / Posi
Limited slip differential.
Production Engine Assembly
A full-dressed PRODUCTION engine, just as delivered to the vehicle assembly plants,
which is sold through SERVICE. These are exactly the same as the engine installed in
passenger cars or trucks. PRODUCTION engine assemblies are usually only available during
the current model year or until GMSPO inventory of the PRODUCTION
engines is exhausted.
Protect-o-plate
This a metal warranty card which has the original purchaser's name on it. It also has
some information on the original configuration of the car, not as extensive as the build
sheet. It was first included in 1965.
Small Block Chevrolet engine. Chevrolet engines derived from the 265 cubic inch, block design first introduced
in 1955. SBC's include 283's, 302's, 305's, 307's 327's, 350's, and
400's.
Service Engine
This is an engine assembly which is composed of all PRODUCTION pieces and is configured
the same as a PRODUCTION configuration. It usually lacks some of the peripheral components
which must be transferred from the replaced engine or otherwise acquired. When completed,
it will have the same configuration as the replaced engine.
Shark
1968 Corvettes were designated Shark.
Side Pipe / Side Exhaust
Optional equipment available on 1965 through 1967 and 1969.
Small Block
Chevrolet engines derived from the 265 cubic inch, block design first introduced
in 1955. SBC's include 283's, 302's, 305's, 307's 327's, 350's, and
400's.
Replacement engine that usually includes only the block, crank, connecting rods,
pistons, camshaft, timing gears and chain. It is all assembled and ready for heads
and valve train components, intake manifold, carburetor or fuel injection, exhaust
manifolds, and other items too numerous to mention. This referred to as a
"Partial Engine" by GM
SHP / Special High Performance
A Higher performance carburetor engine, either small block or big block, generally with
a mechanical lifter cam, however, some had special hydraulic lifter cams.
Sting Ray
1963 - 1967 Corvettes were designated Sting Ray. Note there seems to be some question of
the 1968 model was it a Sting Ray, or a Stingray, or neither?
Stingray
1969 - 1976 Corvettes were designated Stingray.
Straight Axle / Solid Axle
1953 -1962 Corvettes. These are the Corvettes that predate the 4 wheel independent
suspension of 1963 and later cars.
SWC - S/W/C * Split Window Coupe
1963, only Corvette Coupe with the two piece rear window. One year only feature
due to poor rear visibility.
Guide Lamp T-3 headlamps used from 1956 to 1972 in different configurations.
T-top
Removable top panels. Two panels one over the drive seat and the other over the
passenger seat.
Tank Sticker, Build Sheet
It lists all the options the car had originally. Starting in with '67s, it is glued to
the top of the gas tank. Later years also may find them stashed various places inside the
car. A great piece of authentication, since Chevy has no records of how each car was
equipped. The National Corvette Museum has recently been given access to copies of all of
the build sheets from the Bowling Green Plant. This applies to 1981 and later cars
that were manufactured at Bowling Green. The Museum is now offering a service of
reproducing a copy of the build sheet and the Window Sticker. See the NCM web
site for further information. Like everything else, can be faked.
Targa Top
Removable single top panel. Opens car roof from side to side.
Transmission Controlled Spark. Common in late 60's early 70's.
THM
Turbo Hydra Matic Transmission
TL
*TL* NCRS Technical Discussion Board and NCRS Discussion
Board. Used to denote posts by NCRS Team Leaders or other NCRS Officials.
It is used to identify posts as being genuine.
TI / Transistor Ignition
Tri Power / 3 deuces / 3 X 2 / Three two Barrel Carburetors
The "ZO6" was the hottest '63 Corvette variation.
Equipped with heavy-duty suspension and heavy duty brakes, it was only available
as a 327 cubic inch 360 horsepower, fuel-injected 4 speed transmission Coupe.
Early production provided a special 36 gallon fuel tank, later versions could
be ordered with a standard fuel tank. 199 ZO6's were built, and less than
90 are believed to have been the "big tank" version.
ZR1
1970-72 Special Purpose Package: (Not recommended for normal traffic situations)
Includes LT1, 370-hp 350 cu-in. engine, special 4-speed close-ratio
transmission, HD power brakes, full transistor ignition system, aluminum radiator,
special springs with matching shock absorbers, special front and rear stabilizer
bars. 1972 included 255-hp engine available for registration in California.
1990-95 LT5 engine, an aluminum-block V-8 with the same bore as the standard
(L98) 350ci displacement unit, but with 375 horsepower. To accomplish this
power boost, the new block featured four overhead camshafts and 32 valves.
The LT5s were built by Mercury Marine in Oklahoma and assembled into the ZR-1
vehicle at Bowling Green. Available only in coupe configuration, the
ZR-1 was distinguishable from other Corvette coupes by its wider tail section,
its now convex rear fascia and four "square" taillights. 6,939
ZR-1s were turned out.
ZR2
1971-72 Special Purpose Package: (Not recommended for normal traffic situations)
Includes LS6, 425-hp 454 cu-in. engine, special 4-speed close-ratio
transmission, HD power brakes, full transistor ignition system, aluminum radiator,
special springs with matching shock absorbers, special front and rear stabilizer
bars.
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