SERVICE MANUALCYLINDER HEAD & VALVESSection 3e.Use valve guide installer (See Introductionfor tool list) to install new guide. Keep valveguide recession from cylinder head surfaceat limits specified below:NOTE: Install valve guides with (internal) threadedportion down. The 30 degree chamfer at the top ofthe guide is Intended to allow excess oil to drainaway from the top of the guide and the threads areintended only to distribute the small amount of oilwhich enters the guide, not to introduce oil.Inverting the guides can lead to excessive oilconsumption.300 SERIESIntakeExhaust25.20 mm (0.992 in)32.31 mm (1.272 in)25.70 mm (1.012 in)32.82 mm (1.292 in)400 SERIESIntakeExhaust30.66 mm (1.207 in)32.69 mm (1.287 in)31.17 mm (1.227 in)33.20 mm (1.307 in)Inspect and Repair Valves as follows:1.Visually INSPECT each valve for excessiveWEAR, BURN MARKS, WAR- PAGE, PITTINGor SCUFFING at:a.Valve Stem Grooves.b.Valve Stems.c.Valve Heads2.Replace valves which are seriously bent, worn,burnt, warped, pitted or scuffed.3.Resurface valve face angle, if necessary.a.Maintain a minimum valve face margin of1.73 mm (0.068 in) for intake valves and1.14 mm (0.045 in) for exhaust valves on300 Series engines.b.On 400 Series engines maintain a minimumvalve face margin of 2.24 mm (0.088 in) forintake valve and 1.14 mm (0.045 in) forexhaust valves. See Fig. 26.Figure 26. - Examples of Valve Face Marginc.Maintain valve face angles as shown in Fig.27.Figure 27. - Valve Face Angles (300/400Series)NOTE:An incorrect margin will not provide properheat dissipation and lead to warpage or breakage.4.Resurface valve face angle as follows:a.Set valve in grinder to desired angle.b.Dress the wheel to proper angle.c.Take a light cut-off valve face anglesurface, as shown in Fig. 28.CGES-185-3PRINTED IN UNITED STATES OF AMERICAPage 21
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
