MTU Gas engine8 V 4000 L62 Operating Instructions Manual page 63

Measuring valve depth
1. Check TDC position of piston in cylinder A1:
• If the rocker arms are unloaded on cylinder A1, the piston is in firing TDC.
• If the rocker arms are under load on cylinder A1, the piston is in overlap TDC.
2. Measure valve depth for each valve in two crankshaft positions (firing TDC and overlap TDC for cylinder
A1) according to the diagram. Diagram (→ Page 60).
3. Release adjusting screw (1) and remove
valve bridge. Do not remove rocker arm (2)!
4. Measure distance between valve stem end
and cylinder head top at the spark plug
bore with depth gauge (see figure).
• The specified value for a new cylinder
head: 93.8 mm.
• Admissible wear: 3 mm.
• If the measured value is > 96.8 mm, re‐
place the relevant cylinder head ahead of
schedule (→ Instructions for Overhaul of
Assemblies).
5. Install valve bridge.
6. Adjust valve clearance (→ Page 60)
Final steps
1. Remove barring device (→ Page 48).
2. Check condition of O-rings at the sleeves, replace if damaged.
MS150032/02E 2012-07 | Task Description | 63