N'oge ntụgharị dị ala, mmegharị nke piston injin na-eji nwayọ nwayọ, ike mmịpụta na-adọta ngwakọta n'ime cylinders na-ebelata. N'oge a, ọ dị mkpa ka emeghe valvụ ihe oriri ruo ogologo oge o kwere mee, mgbe piston na-agbaba na etiti ndị nwụrụ anwụ ma banye na strok mkpakọ, a na-emechi valvụ ihe oriri ozugbo iji gbochie gas agwakọta ka ọ pụta. Ebe camshaft nke nwere akụkụ obe nke "karịrị" na-emechi valvụ oriri ngwa ngwa, camshaft "rounder" na-ewe ogologo oge iji mechie. Yabụ, na rpm dị ala, injin ahụ chọrọ camshaft “dị nkọ”.

N'ebe dị elu, piston nke injin ahụ na-emegharị ngwa ngwa, na ike ịmịnye ihe na-adọta ngwakọta n'ime cylinder na-esiwanye ike. Ọbụlagodi mgbe piston na-agbaba na etiti nwụrụ anwụ ma na-achọ ịbanye na strok mkpakọ, gas agwakọtara ga-abanye n'ime cylinder n'oge a enweghị ike ịkwụsị ya. N'ezie nke a bụ ihe anyị chọrọ, n'ihi na ọ bụrụ na ọtụtụ n'ime ngwakọta nwere ike ịdọrọ n'ime cylinder, mgbe ahụ, engine nwere ike nweta ike ọzọ. N'oge a, anyị kwesịrị idobe valvụ oriri na-emeghe mgbe piston na-ebili, ma ghara imechi ya maka oge a. camshaft "rounder" dị ugbu a na ebe a!

Ọdịdị nke ngalaba cam engine nwere njikọ chiri anya na ọsọ engine. N'ikwu ya n'ụzọ dị mfe, na obere revs anyị chọrọ camshaft "nkọwa"; na elu revs anyị chọrọ a "rounder" camshaft.