This assembly consists of the bare engine block fitted with the rotating assembly, which includes the crankshaft, connecting rods, and pistons. It does not include the cylinder head, valvetrain, timing components, or external accessories. Mechanics order these assemblies when the bottom end suffers catastrophic failure but the top end components remain salvageable.
The heads are fine but we spun a main bearing, so we're just going to order a short block.
Buying a short block saves money on parts but requires significantly more labor to clean and transfer the old cylinder heads and timing gear.
Do not mix it up with
- Long block: A short block is just the bottom end, whereas a long block includes the cylinder heads and valvetrain.
Related terms
Long block
A replacement engine assembly that includes the engine block, rotating assembly, cylinder heads, and valvetrain.
Bottom-end
The lower section of an engine block containing the crankshaft, connecting rods, and main bearings.
Crate engine
A fully assembled, brand-new or remanufactured engine delivered ready to install.