Pamarevs akaderera, kudzokororwa kweinjini pistons kunononoka, uye simba rekukwevera rekukwevera musanganiswa mumasilinda rinoderedzwa. Panguva ino, vharuvhu yekupinda inoda kuvhurwa kwenguva yakareba sezvinobvira, uye apo piston inomhanya ichidzika pasi yakafa pakati uye inopinda mukumanikidza sitiroko, vheji yekupinda inovharwa pakarepo kudzivirira gasi rakasanganiswa kubuda kunze. Nepo camshaft ine "sharper" cross-section inovhara valve yekupinza nekukurumidza, "rounder" camshaft inotora nguva yakareba kuvhara. Saka, panguva yakaderera rpm injini inoda "yakapinza" camshaft.

Pamarevs akakwirira, piston yeinjini inodzoka nekukurumidza, uye simba rekukwevera rekukwevera musanganiswa mucylinder rakasimba. Kunyangwe iyo piston ichimhanya ichienda kuzasi kwakafa pakati uye yave kuda kupinda mukumanikidza sitiroko, gasi rakasanganiswa rinopinda muhumburumbira panguva ino uye haigone kukanganiswa. Zvechokwadi izvi ndizvo zvatinoda, nokuti kana yakawanda yemusanganiswa inogona kukweverwa muhumburumbira, ipapo injini inogona kuwana simba rakawanda. Panguva ino, tinoda kuchengetedza vheji yekutora yakazaruka apo piston inosimuka, uye usaivhara kwenguva. Iyo "rounder" camshaft yava pachiitiko!

Chimiro chechikamu chejini cam chakabatana zvakanyanya nekumhanya kweinjini. Kuzvitaura zviri nyore, pa low revs tinoda "sharper" camshaft; pahigh revs tinoda "rounder" camshaft.