Mercedes-Benz 602, Service Manual

Page: 162 / 324

Pistons with angular channel
Due to the higher thermal load the pistons are
cooled with oil via an annular channel in the
piston crown. Moreover the piston pins are
supplied with oil injected through the two bores
(2.0 mm dia., arrows), ending in the annular
channel.
The required oil is supplied via injection nozzles
located in the crankcase on the right side.
The annular channel is deleted on engine
603.970. Only the piston crown is supplied
with oil.
A
recess is
located on the piston skirt (arrow) for
the oil injection nozzle.
The prechamber recess in the piston crown has
a diameter of 18 mm (normally aspirated engine
=
Piston crown
On
engines
602.96
and
603.97
from the start of
production and on engine
603.96
starting
‘moose horn’ recess pistons are installed
(previously ‘star’ recessed pistons).
The piston
crown is coated with aluminum oxide
on both piston versions.
A. ‘Moose
horn'
P O 3 2 2 1 0 - 1 3
03.10