Plain English Meaning

The strong central case of a piston engine. It holds the crankshaft in place, supports the cylinders that bolt onto it, and keeps the engine oil inside.

Full Definition

The main housing of a reciprocating aircraft engine that encloses and supports the crankshaft, connecting rods, bearings, and other internal moving parts. It also provides mounting surfaces for the cylinders and accessories, and contains the engine's lubricating oil.

Context Anchor

Seen in aircraft engine descriptions, maintenance inspections, oil leak checks, and discussions of piston engine construction.

Derivation

From 'crank' (the rotating shaft that converts motion into rotary motion) plus 'case' (an enclosing container). Literally, the case that houses the crankshaft.