SERIES 60 SERVICE MANUAL 1.4 VALVES, SPRINGS, GUIDES, INSERTS, SEALS AND ROTATORS Four valves per cylinder, two each intake and exhaust, give the Series 60 engine excellent breathing and cooling characteristics. See Figure 1-64. Figure 1-64 Intake and Exhaust Valve Arrangements Valves are made of heat-treated alloys, with heads and stems precision ground. Stem ends are hardened to minimize wear in contact with the valve rocker buttons. Hard-alloy valve seat inserts, pressed into both intake and exhaust ports, can be replaced when worn to restore new engine performance. All information subject to change without notice. (Rev. 2005) 6SE483 0507 Copyright © 2005 DETROIT DIESEL CORPORATION 1-79