Manifolds, Cylinder Head & Valves

i)Assemble the valve rocker arm assemblies as detailed. Loosen the lock nuts on each valve lever and back of the adjusting screw.

j)Install the valve rocker arm assembly as detailed. Replace the longer cap screw through the center bracket and retorque to the correct figure.

k)Install the thermostat housing.

l)Install the thermostat bypass hose.

m)Reassemble the fuel injection pipes.

n)Refit the intake and exhaust manifolds.

o)Adjust the tappet clearance after the cylinder head is tightened to the correct torque for adjustments.

Tips for service of cylinder head

1)During cylinder head overhaul, Nozzle protrusion (protrusion of nozzle tip from head bottom face) should be checked thoroughly as it affects the fuel spray pattern of the nozzle.

2)Excessive carbon deposition on valve neck and valve stem indicates engine oil consumption due to excessive clearance between stem and valve guide.

3)Discard valve springs if they have lost tension or are broken.

4)Always replace valve collects whenever valves are opened for inspection or repairs.

5)Improper valve spring tension, valve lapping, tappet setting, timing or excessive cam lobe wear will cause valve seat damage and subsequent leakage.

6)While replacing piston rings ensure that the valve seats are ground/lapped for perfect seating to avoid oil throw from the exhaust.

7)While regrinding the valve maintain it’s concentricity with the guide to ensure proper seating.

8)Never remove the cylinder head in hot condition.