--- waxaa qoray Aaron Turpen 20-Mar-2015
Markaad bedesho suunka wakhtiga/silsiladda ama hagaajinta wakhtiga gaadhiga, fahanka calamadaha wakhtiga ku yaal shafka iyo jiidhyada kamaradadu waxay fure u tahay in la saxo. Tuners ayaa sidoo kale u baahan doona inay si dhow uga warqabaan calaamadahan maadaama ay muhiim u yihiin hagaajinta qiimayaasha RPM.

Inta badan mishiinnada waxay yeelan doonaan laba ama saddex calaamadood oo ku yaal jiidh-jilicsan ee gudaha si ay ula jaanqaadaan calaamadda "falaarta" ee ku taal block engine. Calaamado la mid ah ayaa sida caadiga ah laga heli doonaa ugu yaraan mid ka mid ah jilbaha-camshaft-yada. Marka suunka waqtiga ama silsiladda si habboon loo rakibo, calaamadda ku dheggan calaamadda xannibaadda ee shafka-mushaarka waxay la mid noqon doontaa calaamadda lagu dhejiyay shafka iyo madaxa. Hadafka dejinta wakhtiga waa in safkan uu dhaco.

Calaamadda xarunta dhintay ee sare (TDC) waxay noqon kartaa xarunta, bidix, ama summada midig, iyadoo ku xidhan mishiinka. Inta badan mishiinnada, waa udub dhexaadka saddexda calaamad, laakiin gaadhigaaga gaarka ahi wuu ka duwanaan karaa, markaa tixraac buug-gacmeedka mulkiilahaaga iyo/ama buug-gacmeedyada dayactirka dukaanka.