Izinjini ezingu-645 zochungechunge zangena ekukhiqizeni ngo-1965. Njengoba uchungechunge lwe-567 lwalufinyelele umkhawulo ekukhuphukeni kwamandla amahhashi, kwakudingeka ukufuduka okukhulu; lokhu kufezwe ngokukhuphula ibhore ukusuka ku-8+1⁄2 ku-(216 mm) ochungechungeni lwe-567 ukuya ku-9+1⁄16 ku-(230 mm) ochungechungeni lwe-645, kuyilapho kugcinwa ukushaywa okufanayo nokuphakama kwedekhi. Ngenkathi i-crankcase ishintshiwe kusukela ochungechungeni lwe-567, 567C kanye nezinjini zakamuva (noma izinjini ezingu-567 eziguqulelwe ekucacisweni kwe-567C, ngezinye izikhathi ezibizwa ngokuthi izinjini ezingu-567AC noma ezingu-567BC) zingamukela izingxenye zesevisi engu-645, njengama-assemblies anamandla. Ngokuphambene, injini engu-567E isebenzisa ibhulokhi yochungechunge engu-645E enama-assemblies wamandla ochungechunge angu-567.

Zonke izinjini ezingama-645 zisebenzisa i-Roots blower noma i-turbocharger ukuze kukhishwe isilinda. Ezinjinini ezine-turbocharged, i-turbocharger idonsa ngegiya futhi ine-clutch edlulayo eyivumela ukuthi isebenze njenge-centrifugal blower ngesivinini esiphansi senjini (lapho ukugeleza kwegesi kanye nezinga lokushisa kukodwa kunganele ukushayela i-turbine) kanye ne-turbocharger eqhutshwa yi-exhaust. ngesivinini esiphezulu. I-turbocharger ingabuyela ekusebenzeni njengeshaja enkulu ngesikhathi sokufuna ukwanda okukhulu kwamandla okukhipha injini. Nakuba kubiza kakhulu ukuyigcina kune-Roots blowers, i-EMD ithi lo mklamo uvumela “kakhulu” ukunciphisa ukusetshenziswa kukaphethiloli nokukhipha umoya, ukusebenza okuthuthukisiwe kokuphakama kokuphakama okuphezulu, ngisho nokwenyuka okungafika kwamaphesenti angama-50 kwamandla ahhashi akalwe kakhulu ngaphezu kwezinjini eziphehlwa yi-Roots okufanayo. ukususwa kwenjini.