What is a 'short block'?

A 'short block' is an engine that includes only the following components:

• the engine block (the 'bottom half' of the engine, where the pistons are);
• the pistons, piston rings, and connecting rods;
• the crankshaft; and
• all the bearings and fasteners for the above.

A short block could be defined as a complete 'lower half' of an engine. However, short blocks usually do not have an oil pump, oil pan, or water pump.