A na-akpọ akụkụ ala nke ngọngọ cylinder ebe a na-etinye crankshaft crankcase. A na-ekewa crankcase ka ọ bụrụ nnukwu crankcase dị elu na obere crankcase. A na-atụba crankcase elu na ngọngọ cylinder ka otu ahụ. A na-eji obere crankcase dị ala na-echekwa mmanụ na-ete mmanụ ma mechie crankcase nke elu, ya mere a na-akpọkwa ya pan mmanụ. Obere mmanụ ahụ nwere obere ike, a na-esikwa n'efere ígwè dị mkpa tee ya. Ọdịdị ya na-adabere n'ozuzu nhazi nke engine na ikike mmanụ. A na-etinye baffle mmanụ n'ime ite mmanụ iji gbochie oke mgbanwe na ọkwa mmanụ mgbe ụgbọ ala na-aga. A na-ejikwa ihe nkwụnye mmanụ na-agbapụta n'ala ala mmanụ, na-emekarị magnet na-adịgide adịgide n'elu plọg mmanụ na-agbapụta mmanụ iji nweta ibe ígwè n'ime mmanụ na-agba mmanụ ma belata ike engine. A na-etinye gasket n'etiti oghere nkwonkwo nke elu na nke ala crankcases iji gbochie nsị mmanụ.

The crankcase bụ akụkụ kasị mkpa nke engine. Ọ na-ebu ike na-ebufe site na mkpanaka njikọ ma gbanwee ya ka ọ bụrụ torque ka ọ pụta site na crankshaft ma mee ka ngwa ndị ọzọ dị na engine rụọ ọrụ. A na-edobe crankshaft site na ngwakọta nke ike centrifugal nke uka na-atụgharị, ike ikuku gas na-emegharị oge na ike na-emegharị ahụ, nke mere na a na-edobe ihe na-agbagọ na-ehulata na ibu torsion. Ya mere, a chọrọ crankshaft ka ọ nwee ike zuru oke na isi ike, na elu nke akwụkwọ akụkọ kwesịrị ịdị na-eyi ihe na-adịghị mma, na-arụ ọrụ n'otu n'otu, ma nwee ezigbo nguzozi.

Ihe mkpuchi crankcase ga-agwụ elu kọntaktị n'etiti nnukwu njedebe nke njikọ njikọ na akwụkwọ akụkọ n'ihi mmanụ na-adịghị ọcha na ike na-enweghị isi nke akwụkwọ akụkọ ahụ. Ọ bụrụ na mmanụ ahụ nwere nnukwu adịghị ọcha na nke siri ike, enwerekwa ihe ize ndụ nke ịcha elu akwụkwọ akụkọ. Ọ bụrụ na iyi ahụ siri ike, ọ ga-abụ na ọ ga-emetụta ogologo strok nke piston ahụ elu na ala, belata nrụpụta ọkụ ọkụ, ma na-ebelata mmepụta ike. Na mgbakwunye, crankshaft nwekwara ike ịkpata ọkụ n'elu akwụkwọ akụkọ n'ihi mmanye ezughị oke ma ọ bụ mmanụ dị oke mkpa, nke nwere ike imetụta mmegharị piston na-emegharị ahụ n'ọnọdụ ndị siri ike. Ya mere, a ga-eji mmanụ mmanye nke viscosity kwesịrị ekwesị mee ihe ma hụ na ịdị ọcha nke mmanụ ahụ dị ọcha.