housing vs crankcase

housing and crankcase both are nouns.

Word	Noun	Adjective	Verb	Adverb
housing	Yes	No	No	No
crankcase	Yes	No	No	No

As nouns, crankcase is a hyponym of housing; that is, crankcase is a word with a more specific, narrower meaning than housing:

housing: a protective cover designed to contain or support a mechanical component
crankcase: housing for a crankshaft

housing (noun)	crankcase (noun)
structures collectively in which people are housed	housing for a crankshaft
a protective cover designed to contain or support a mechanical component
stable gear consisting of a decorated covering for a horse, especially (formerly) for a warhorse