Ọrụ nju oyi mmanụ nnyefe
N'ihi na mmanụ nwere thermal conductivity na mgbe niile na-eru na engine, mmanụ ngwa nju oyi na-arụ a jụrụ ọrụ na engine crankcase, clutch, valve mgbakọ, wdg Ọbụna maka mmiri jụrụ engines, nanị akụkụ nke nwere ike mma site na mmiri bụ. isi cylinder na mgbidi cylinder, na akụkụ ndị ọzọ ka na-ajụ oyi site na ngwa nju oyi mmanụ.