counterbore on each side that the hollow dowel goes
through. An O-ring is in each counterbore to prevent
oil leakage around the hollow dowel. Oil flows
through the hollow dowel into a vertical passage in
the cylinder head to the rocker arm shaft bracket.
The rocker arm shaft has an orifice to restrict the oil
flow to the rocker arms. The rear rocker arm bracket
also has an O-ring that seals against the head bolt.
This seal prevents oil from going down around the
head bolt and leaking past the head gasket or spacer
plate gasket. The O-ring must be replaced each time
the head bolt is removed from the rear rocker arm
All the riming gear bearings get lubricant under
pressure from the oil manifold through connecting
Oil goes to the components and attachments on
the outside of the engine through supply lines which
connect to the oil manifold. These components and
attachments are: turbocharger, air compressor and
After the lubrication oil has done its work, it goes
back to the engine oil pan.