Turning the valve seats

Turning the valve seats

• If necessary, turn the valve seats using suitable equipment.

Valve seat taper "α" 90° ± 20'

Checking the clearance between rockers and support shaft

1. Check that the inside diameter of the rockers is within the specified limits.

Inside diameter of rockers 16.010 + 0.028 mm

1. Check that the diameter of the rocker shaft is within the specified limits.

Diameter of rocker support shaft 15.988 ÷ 16.000 mm

1. Calculate the clearance between rockers and support shaft checking that it is within the specified limits.

Clearance between rockers and support shaft 0.010 + 0.040 mm

After machining, grind each valve in its seat as follows:

• coat the contact surfaces "A" and "B" of the valves and their seats with abrasive paste (SIPAL AREXONS Carbosilicium for valves);
• lubricate the valve stem with engine oil;
• fit the lower surface of the valve mushroom to the suction cup "C" of a pneumatic grinder;
• insert the valve in its guide and grind;
• after grinding, thoroughly clean the valve and the seat.