Abstract: A dynamoelectric machine includes a plurality of groups of assembled laminations, each having two opposed end walls with at least one of the end walls incuding a plurality of locating recesses and spacer engaging tabs. The groups of laminations are secured within the machine between two end clamps. A plurality of spacers securable between adjacent ones of the groups and between the groups and the clamps provides air vents within the machine. Each of the spacers includes a keying arm portion engagable with one of the locating recesses to position the spacer relative to one end wall. The spacer engaging tabs abut the spacers, when so positioned by the locating recesses, to prevent adverse vibrational movement of the spacers during machine operation.