1999 Volvo Penta "WT" Models Workshop Manual, Page 275Get this manual
a.lf necessary, dress the valve refacing machine grinding wheel to make sure it is smooth and trueSet chuck at 45 mark for grinding valvesbClamp the valve stem in the chuck of the machinecStart the grinder and move the valve head out in line with the grinder wheel by moving the lever to the leftdTurn the feed screw until the valve head just contacts wheelMove valve back and forth across the wheel and regulate the feed screw to provide light valve contacteContinue grinding until the valve face is true and smooth all around valveIf this makes the valve thin, the valve must be replaced as the valve will overheat and burnfRemove valve from chuck and place stem in "V" blockFeed valve squarely against grinding wheel to grind any pit from rocker arm end of stemNOTE: Only the extreme end of the valve stem is hardened to resist wearDo not grind end of stem excessivelygAfter cleaning valve face and cylinder head valve seat of grinding particles, make pencil marks about in(6,35 mm) apart across the valve face, place the valve in cylinder head and give the valve one-half turn in each direction while exerting firm pressure on face of valvehRemove valve and check face carefullyIf all pencil marks have not been removed at the point of contact with the valve seat, it will be necessary to repeat the refacing operation and recheck for proper seating iGrind and check remaining valves in the same mannerAssembly