Someone at the meet says they are putting a long block in, and someone else says it is a small block with a big block in the shed. Both of them assume you know what that means. This is the guide to engine terms as car people actually use them: what a short block and a long block are, what makes a big block big, and the words around a rebuild that get thrown about like everyone was born knowing them. Plain definitions, no fluff.
Short block, long block, complete engine
These describe how much of an engine you are getting, and they come up whenever an engine is bought, sold or rebuilt.
Bare block. Just the block: the cast iron or aluminium casting with the cylinders in it. Nothing inside, nothing bolted on.
Short block. The block with its rotating assembly fitted: crankshaft, connecting rods, pistons and bearings, and usually the camshaft if it lives in the block. No cylinder heads, no valvetrain, nothing on top. This is the bottom end, assembled.
Long block. A short block plus the cylinder heads, valves, camshaft or camshafts and the valvetrain. Often the timing cover and sump as well, though what exactly is included varies by seller, so ask. A long block is an engine that will run once you add everything that feeds and fires it.
Complete engine, turnkey, dressed. A long block plus the intake, exhaust manifolds, ignition, fuel system, water pump, alternator and the rest of the accessories. Bolt it in, connect it up, start it.
Crate engine. A new complete or long block engine sold in a crate by the manufacturer or a specialist, as opposed to one pulled from a car. The LS crate engine is why half the hot rods in the world have the same motor.
The rule of thumb: short block is the bottom end, long block adds the top end, complete adds everything else.
Big block and small block
These are families of American V8, and the words are about the physical size of the engine, not the capacity of one particular version.
Small block. The compact V8 families. Chevrolet's small block from 1955 (265 to 400 cubic inches over the years) is the one the term was coined for; Ford's Windsor (289, 302, 351W) and Cleveland (351C), Chrysler's LA (318, 340, 360), and Holden's own 253 and 308 are all small blocks. Lighter, physically smaller, fits in more engine bays. The GM LS family is the modern small block, which is why an LS swap is a small block swap.
Big block. The larger, heavier V8 families built for the bigger cars, trucks and drag strips: Chevrolet's 396, 427 and 454, Ford's FE (390, 427, 428) and 385-series (429, 460), Chrysler's B and RB (383, 440) and the 426 Hemi. Bigger bore spacing, taller deck, more capacity, more weight. A big block in a small car is a muscle car cliche for a reason.
The trap: a 400 cubic inch small block Chev is bigger in capacity than a 396 big block. Big and small describe the family and the casting, not the number on the air cleaner.
The rebuild words
Bottom end, top end. The bottom end is the crank, rods, pistons and bearings. The top end is the heads, valves and cam. "Fresh bottom end" means it has been rebuilt; "top end job" means the heads were done and the bottom left alone.
Rebuild, reco. Stripping the engine, measuring everything, replacing what is worn and machining what needs it. Reco is the Australian word for a reconditioned engine, usually an exchange unit from a shop.
Rebore, overbore, thirty thou over. Machining the cylinders slightly larger to clean up wear, then fitting oversize pistons. Thirty thou over is 0.030 of an inch over standard, the most common oversize.
Sleeved. A cylinder that has been machined out and fitted with a new liner, because it was too worn or damaged to bore.
Decked. The top face of the block (or the head) machined flat, which also raises compression slightly.
Stroker, bored and stroked. A longer-throw crankshaft that increases the stroke and therefore the capacity. A 302 Windsor becomes a 347 stroker; a 350 Chev becomes a 383. Bored and stroked means both were done.
Balanced and blueprinted. Balanced: the rotating assembly weighed and matched so it spins without vibration. Blueprinted: every clearance set to the exact design figure rather than the factory tolerance range. The words for an engine built properly rather than assembled.
Forged, cast. What the pistons, rods and crank are made from. Cast is standard and fine for standard power. Forged is stronger and what a boosted or high-revving engine needs. "Forged internals" is the phrase.
Built motor, stock bottom end. Built means the internals have been upgraded to take more power. Stock bottom end means they have not, and there is a limit to how much boost it will take before it lets go. Every forum argument about turbo kits is really about this.
Ported and polished. The intake and exhaust passages in the heads reshaped and smoothed for better flow. A head job is a rebuild of the heads; porting is the performance version.
Cam, bumpstick, lumpy cam. The camshaft decides when the valves open and for how long. A bigger cam gives more top-end power at the cost of a rough idle, which is the lumpy sound people pay for. Roller and flat tappet describe the type of lifter riding on it.
Compression. The ratio the piston squeezes the mixture to. Higher makes more power and wants better fuel; boosted engines usually run lower.
Swaps and the engines people name
Engine swap, conversion. Fitting an engine the car never came with. Australia says conversion as often as swap.
LS. GM's modern small block family (LS1, LS2, LS3, the truck LQ and LM versions). Cheap, light, strong, everywhere. "LS swap everything" is a joke because it is true.
Barra. Ford Australia's inline six from the Falcon, turbocharged in the XR6 Turbo and FPV cars. The local answer to the LS: tough bottom end, takes a lot of boost stock, now swapped into everything.
RB, JZ, SR. Nissan's RB26 and RB30, Toyota's 2JZ and 1JZ, Nissan's SR20: the Japanese inline engines that built drift and import culture. 2JZ is the one your mate says will take a thousand horsepower.
Hemi. Chrysler's hemispherical-chamber V8, old and new. Also a Chrysler Australia six in the 1970s Valiants, which confuses Americans.
Rotary. Mazda's Wankel engine, no pistons at all, in the RX-3, RX-7 and RX-8. Beloved, thirsty, and the reason "brap" is a word.
Every one of these engines and the cars they came in has a page on Drivesome, the social network for car enthusiasts, with photos and builds from the people running them. If a term is missing, ask there and someone will argue about it for a week.
More on car people
Questions people ask
What is the difference between a short block and a long block?
A short block is the engine block with the crank, rods and pistons fitted and no cylinder heads. A long block adds the heads, valves and camshaft. A complete engine adds the intake, exhaust, ignition, fuel system and accessories.
What is the difference between a big block and a small block?
They are families of V8 defined by the size of the casting, not the capacity of one version. Small blocks (Chevrolet 350, Ford 302, Holden 308) are lighter and physically smaller; big blocks (Chevrolet 454, Ford 460, Chrysler 440) are larger and heavier with more capacity.
Is the LS a small block?
Yes. The LS family is General Motors' modern small block, which is why it fits in so many engine bays and gets swapped into everything.
What does thirty thou over mean?
The cylinders have been bored 0.030 of an inch larger than standard during a rebuild, with matching oversize pistons.
