Short block is an automotive term describing a bare engine including the block, crankshaft, and pistons, but not including the head, manifolds or any accessories like alternator or power steering pump. May or may not include camshaft. The camshaft will probably be included if the engine is a pushrod design and will not be included if it uses an overhead camshaft.
In other words, a short block is only the "bottom end" of the engine.
See also: Long block.
